Kconfig 65 KB

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  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_KRETPROBES
  28. select HAVE_FTRACE_MCOUNT_RECORD
  29. select HAVE_DYNAMIC_FTRACE
  30. select HAVE_FUNCTION_TRACER
  31. select HAVE_FUNCTION_GRAPH_TRACER
  32. select HAVE_FUNCTION_TRACE_MCOUNT_TEST
  33. select HAVE_KVM
  34. select HAVE_ARCH_KGDB
  35. select HAVE_ARCH_TRACEHOOK
  36. select HAVE_GENERIC_DMA_COHERENT if X86_32
  37. select HAVE_EFFICIENT_UNALIGNED_ACCESS
  38. select USER_STACKTRACE_SUPPORT
  39. config ARCH_DEFCONFIG
  40. string
  41. default "arch/x86/configs/i386_defconfig" if X86_32
  42. default "arch/x86/configs/x86_64_defconfig" if X86_64
  43. config GENERIC_TIME
  44. def_bool y
  45. config GENERIC_CMOS_UPDATE
  46. def_bool y
  47. config CLOCKSOURCE_WATCHDOG
  48. def_bool y
  49. config GENERIC_CLOCKEVENTS
  50. def_bool y
  51. config GENERIC_CLOCKEVENTS_BROADCAST
  52. def_bool y
  53. depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
  54. config LOCKDEP_SUPPORT
  55. def_bool y
  56. config STACKTRACE_SUPPORT
  57. def_bool y
  58. config HAVE_LATENCYTOP_SUPPORT
  59. def_bool y
  60. config FAST_CMPXCHG_LOCAL
  61. bool
  62. default y
  63. config MMU
  64. def_bool y
  65. config ZONE_DMA
  66. def_bool y
  67. config SBUS
  68. bool
  69. config GENERIC_ISA_DMA
  70. def_bool y
  71. config GENERIC_IOMAP
  72. def_bool y
  73. config GENERIC_BUG
  74. def_bool y
  75. depends on BUG
  76. select GENERIC_BUG_RELATIVE_POINTERS if X86_64
  77. config GENERIC_BUG_RELATIVE_POINTERS
  78. bool
  79. config GENERIC_HWEIGHT
  80. def_bool y
  81. config GENERIC_GPIO
  82. bool
  83. config ARCH_MAY_HAVE_PC_FDC
  84. def_bool y
  85. config RWSEM_GENERIC_SPINLOCK
  86. def_bool !X86_XADD
  87. config RWSEM_XCHGADD_ALGORITHM
  88. def_bool X86_XADD
  89. config ARCH_HAS_CPU_IDLE_WAIT
  90. def_bool y
  91. config GENERIC_CALIBRATE_DELAY
  92. def_bool y
  93. config GENERIC_TIME_VSYSCALL
  94. bool
  95. default X86_64
  96. config ARCH_HAS_CPU_RELAX
  97. def_bool y
  98. config ARCH_HAS_DEFAULT_IDLE
  99. def_bool y
  100. config ARCH_HAS_CACHE_LINE_SIZE
  101. def_bool y
  102. config HAVE_SETUP_PER_CPU_AREA
  103. def_bool y
  104. config HAVE_CPUMASK_OF_CPU_MAP
  105. def_bool X86_64_SMP
  106. config ARCH_HIBERNATION_POSSIBLE
  107. def_bool y
  108. config ARCH_SUSPEND_POSSIBLE
  109. def_bool y
  110. config ZONE_DMA32
  111. bool
  112. default X86_64
  113. config ARCH_POPULATES_NODE_MAP
  114. def_bool y
  115. config AUDIT_ARCH
  116. bool
  117. default X86_64
  118. config ARCH_SUPPORTS_OPTIMIZED_INLINING
  119. def_bool y
  120. # Use the generic interrupt handling code in kernel/irq/:
  121. config GENERIC_HARDIRQS
  122. bool
  123. default y
  124. config GENERIC_IRQ_PROBE
  125. bool
  126. default y
  127. config GENERIC_PENDING_IRQ
  128. bool
  129. depends on GENERIC_HARDIRQS && SMP
  130. default y
  131. config USE_GENERIC_SMP_HELPERS
  132. def_bool y
  133. depends on SMP
  134. config X86_32_SMP
  135. def_bool y
  136. depends on X86_32 && SMP
  137. config X86_64_SMP
  138. def_bool y
  139. depends on X86_64 && SMP
  140. config X86_HT
  141. bool
  142. depends on SMP
  143. default y
  144. config X86_TRAMPOLINE
  145. bool
  146. depends on SMP || (64BIT && ACPI_SLEEP)
  147. default y
  148. config X86_32_LAZY_GS
  149. def_bool y
  150. depends on X86_32 && !CC_STACKPROTECTOR
  151. config KTIME_SCALAR
  152. def_bool X86_32
  153. source "init/Kconfig"
  154. source "kernel/Kconfig.freezer"
  155. menu "Processor type and features"
  156. source "kernel/time/Kconfig"
  157. config SMP
  158. bool "Symmetric multi-processing support"
  159. ---help---
  160. This enables support for systems with more than one CPU. If you have
  161. a system with only one CPU, like most personal computers, say N. If
  162. you have a system with more than one CPU, say Y.
  163. If you say N here, the kernel will run on single and multiprocessor
  164. machines, but will use only one CPU of a multiprocessor machine. If
  165. you say Y here, the kernel will run on many, but not all,
  166. singleprocessor machines. On a singleprocessor machine, the kernel
  167. will run faster if you say N here.
  168. Note that if you say Y here and choose architecture "586" or
  169. "Pentium" under "Processor family", the kernel will not work on 486
  170. architectures. Similarly, multiprocessor kernels for the "PPro"
  171. architecture may not work on all Pentium based boards.
  172. People using multiprocessor machines who say Y here should also say
  173. Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
  174. Management" code will be disabled if you say Y here.
  175. See also <file:Documentation/i386/IO-APIC.txt>,
  176. <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
  177. <http://www.tldp.org/docs.html#howto>.
  178. If you don't know what to do here, say N.
  179. config X86_X2APIC
  180. bool "Support x2apic"
  181. depends on X86_LOCAL_APIC && X86_64
  182. ---help---
  183. This enables x2apic support on CPUs that have this feature.
  184. This allows 32-bit apic IDs (so it can support very large systems),
  185. and accesses the local apic via MSRs not via mmio.
  186. ( On certain CPU models you may need to enable INTR_REMAP too,
  187. to get functional x2apic mode. )
  188. If you don't know what to do here, say N.
  189. config SPARSE_IRQ
  190. bool "Support sparse irq numbering"
  191. depends on PCI_MSI || HT_IRQ
  192. ---help---
  193. This enables support for sparse irqs. This is useful for distro
  194. kernels that want to define a high CONFIG_NR_CPUS value but still
  195. want to have low kernel memory footprint on smaller machines.
  196. ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
  197. out the irq_desc[] array in a more NUMA-friendly way. )
  198. If you don't know what to do here, say N.
  199. config NUMA_MIGRATE_IRQ_DESC
  200. bool "Move irq desc when changing irq smp_affinity"
  201. depends on SPARSE_IRQ && NUMA
  202. default n
  203. ---help---
  204. This enables moving irq_desc to cpu/node that irq will use handled.
  205. If you don't know what to do here, say N.
  206. config X86_MPPARSE
  207. bool "Enable MPS table" if ACPI
  208. default y
  209. depends on X86_LOCAL_APIC
  210. ---help---
  211. For old smp systems that do not have proper acpi support. Newer systems
  212. (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
  213. config X86_BIGSMP
  214. bool "Support for big SMP systems with more than 8 CPUs"
  215. depends on X86_32 && SMP
  216. ---help---
  217. This option is needed for the systems that have more than 8 CPUs
  218. if X86_32
  219. config X86_EXTENDED_PLATFORM
  220. bool "Support for extended (non-PC) x86 platforms"
  221. default y
  222. ---help---
  223. If you disable this option then the kernel will only support
  224. standard PC platforms. (which covers the vast majority of
  225. systems out there.)
  226. If you enable this option then you'll be able to select support
  227. for the following (non-PC) 32 bit x86 platforms:
  228. AMD Elan
  229. NUMAQ (IBM/Sequent)
  230. RDC R-321x SoC
  231. SGI 320/540 (Visual Workstation)
  232. Summit/EXA (IBM x440)
  233. Unisys ES7000 IA32 series
  234. If you have one of these systems, or if you want to build a
  235. generic distribution kernel, say Y here - otherwise say N.
  236. endif
  237. if X86_64
  238. config X86_EXTENDED_PLATFORM
  239. bool "Support for extended (non-PC) x86 platforms"
  240. default y
  241. ---help---
  242. If you disable this option then the kernel will only support
  243. standard PC platforms. (which covers the vast majority of
  244. systems out there.)
  245. If you enable this option then you'll be able to select support
  246. for the following (non-PC) 64 bit x86 platforms:
  247. ScaleMP vSMP
  248. SGI Ultraviolet
  249. If you have one of these systems, or if you want to build a
  250. generic distribution kernel, say Y here - otherwise say N.
  251. endif
  252. # This is an alphabetically sorted list of 64 bit extended platforms
  253. # Please maintain the alphabetic order if and when there are additions
  254. config X86_VSMP
  255. bool "ScaleMP vSMP"
  256. select PARAVIRT
  257. depends on X86_64 && PCI
  258. depends on X86_EXTENDED_PLATFORM
  259. ---help---
  260. Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
  261. supposed to run on these EM64T-based machines. Only choose this option
  262. if you have one of these machines.
  263. config X86_UV
  264. bool "SGI Ultraviolet"
  265. depends on X86_64
  266. depends on X86_EXTENDED_PLATFORM
  267. select X86_X2APIC
  268. ---help---
  269. This option is needed in order to support SGI Ultraviolet systems.
  270. If you don't have one of these, you should say N here.
  271. # Following is an alphabetically sorted list of 32 bit extended platforms
  272. # Please maintain the alphabetic order if and when there are additions
  273. config X86_ELAN
  274. bool "AMD Elan"
  275. depends on X86_32
  276. depends on X86_EXTENDED_PLATFORM
  277. ---help---
  278. Select this for an AMD Elan processor.
  279. Do not use this option for K6/Athlon/Opteron processors!
  280. If unsure, choose "PC-compatible" instead.
  281. config X86_RDC321X
  282. bool "RDC R-321x SoC"
  283. depends on X86_32
  284. depends on X86_EXTENDED_PLATFORM
  285. select M486
  286. select X86_REBOOTFIXUPS
  287. ---help---
  288. This option is needed for RDC R-321x system-on-chip, also known
  289. as R-8610-(G).
  290. If you don't have one of these chips, you should say N here.
  291. config X86_32_NON_STANDARD
  292. bool "Support non-standard 32-bit SMP architectures"
  293. depends on X86_32 && SMP
  294. depends on X86_EXTENDED_PLATFORM
  295. ---help---
  296. This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
  297. subarchitectures. It is intended for a generic binary kernel.
  298. if you select them all, kernel will probe it one by one. and will
  299. fallback to default.
  300. # Alphabetically sorted list of Non standard 32 bit platforms
  301. config X86_NUMAQ
  302. bool "NUMAQ (IBM/Sequent)"
  303. depends on X86_32_NON_STANDARD
  304. select NUMA
  305. select X86_MPPARSE
  306. ---help---
  307. This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
  308. NUMA multiquad box. This changes the way that processors are
  309. bootstrapped, and uses Clustered Logical APIC addressing mode instead
  310. of Flat Logical. You will need a new lynxer.elf file to flash your
  311. firmware with - send email to <Martin.Bligh@us.ibm.com>.
  312. config X86_VISWS
  313. bool "SGI 320/540 (Visual Workstation)"
  314. depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
  315. depends on X86_32_NON_STANDARD
  316. ---help---
  317. The SGI Visual Workstation series is an IA32-based workstation
  318. based on SGI systems chips with some legacy PC hardware attached.
  319. Say Y here to create a kernel to run on the SGI 320 or 540.
  320. A kernel compiled for the Visual Workstation will run on general
  321. PCs as well. See <file:Documentation/sgi-visws.txt> for details.
  322. config X86_SUMMIT
  323. bool "Summit/EXA (IBM x440)"
  324. depends on X86_32_NON_STANDARD
  325. ---help---
  326. This option is needed for IBM systems that use the Summit/EXA chipset.
  327. In particular, it is needed for the x440.
  328. config X86_ES7000
  329. bool "Unisys ES7000 IA32 series"
  330. depends on X86_32_NON_STANDARD && X86_BIGSMP
  331. ---help---
  332. Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
  333. supposed to run on an IA32-based Unisys ES7000 system.
  334. config SCHED_OMIT_FRAME_POINTER
  335. def_bool y
  336. prompt "Single-depth WCHAN output"
  337. depends on X86
  338. ---help---
  339. Calculate simpler /proc/<PID>/wchan values. If this option
  340. is disabled then wchan values will recurse back to the
  341. caller function. This provides more accurate wchan values,
  342. at the expense of slightly more scheduling overhead.
  343. If in doubt, say "Y".
  344. menuconfig PARAVIRT_GUEST
  345. bool "Paravirtualized guest support"
  346. ---help---
  347. Say Y here to get to see options related to running Linux under
  348. various hypervisors. This option alone does not add any kernel code.
  349. If you say N, all options in this submenu will be skipped and disabled.
  350. if PARAVIRT_GUEST
  351. source "arch/x86/xen/Kconfig"
  352. config VMI
  353. bool "VMI Guest support"
  354. select PARAVIRT
  355. depends on X86_32
  356. ---help---
  357. VMI provides a paravirtualized interface to the VMware ESX server
  358. (it could be used by other hypervisors in theory too, but is not
  359. at the moment), by linking the kernel to a GPL-ed ROM module
  360. provided by the hypervisor.
  361. config KVM_CLOCK
  362. bool "KVM paravirtualized clock"
  363. select PARAVIRT
  364. select PARAVIRT_CLOCK
  365. ---help---
  366. Turning on this option will allow you to run a paravirtualized clock
  367. when running over the KVM hypervisor. Instead of relying on a PIT
  368. (or probably other) emulation by the underlying device model, the host
  369. provides the guest with timing infrastructure such as time of day, and
  370. system time
  371. config KVM_GUEST
  372. bool "KVM Guest support"
  373. select PARAVIRT
  374. ---help---
  375. This option enables various optimizations for running under the KVM
  376. hypervisor.
  377. source "arch/x86/lguest/Kconfig"
  378. config PARAVIRT
  379. bool "Enable paravirtualization code"
  380. ---help---
  381. This changes the kernel so it can modify itself when it is run
  382. under a hypervisor, potentially improving performance significantly
  383. over full virtualization. However, when run without a hypervisor
  384. the kernel is theoretically slower and slightly larger.
  385. config PARAVIRT_CLOCK
  386. bool
  387. default n
  388. endif
  389. config PARAVIRT_DEBUG
  390. bool "paravirt-ops debugging"
  391. depends on PARAVIRT && DEBUG_KERNEL
  392. ---help---
  393. Enable to debug paravirt_ops internals. Specifically, BUG if
  394. a paravirt_op is missing when it is called.
  395. config MEMTEST
  396. bool "Memtest"
  397. ---help---
  398. This option adds a kernel parameter 'memtest', which allows memtest
  399. to be set.
  400. memtest=0, mean disabled; -- default
  401. memtest=1, mean do 1 test pattern;
  402. ...
  403. memtest=4, mean do 4 test patterns.
  404. If you are unsure how to answer this question, answer N.
  405. config X86_SUMMIT_NUMA
  406. def_bool y
  407. depends on X86_32 && NUMA && X86_32_NON_STANDARD
  408. config X86_CYCLONE_TIMER
  409. def_bool y
  410. depends on X86_32_NON_STANDARD
  411. source "arch/x86/Kconfig.cpu"
  412. config HPET_TIMER
  413. def_bool X86_64
  414. prompt "HPET Timer Support" if X86_32
  415. ---help---
  416. Use the IA-PC HPET (High Precision Event Timer) to manage
  417. time in preference to the PIT and RTC, if a HPET is
  418. present.
  419. HPET is the next generation timer replacing legacy 8254s.
  420. The HPET provides a stable time base on SMP
  421. systems, unlike the TSC, but it is more expensive to access,
  422. as it is off-chip. You can find the HPET spec at
  423. <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
  424. You can safely choose Y here. However, HPET will only be
  425. activated if the platform and the BIOS support this feature.
  426. Otherwise the 8254 will be used for timing services.
  427. Choose N to continue using the legacy 8254 timer.
  428. config HPET_EMULATE_RTC
  429. def_bool y
  430. depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
  431. # Mark as embedded because too many people got it wrong.
  432. # The code disables itself when not needed.
  433. config DMI
  434. default y
  435. bool "Enable DMI scanning" if EMBEDDED
  436. ---help---
  437. Enabled scanning of DMI to identify machine quirks. Say Y
  438. here unless you have verified that your setup is not
  439. affected by entries in the DMI blacklist. Required by PNP
  440. BIOS code.
  441. config GART_IOMMU
  442. bool "GART IOMMU support" if EMBEDDED
  443. default y
  444. select SWIOTLB
  445. select AGP
  446. depends on X86_64 && PCI
  447. ---help---
  448. Support for full DMA access of devices with 32bit memory access only
  449. on systems with more than 3GB. This is usually needed for USB,
  450. sound, many IDE/SATA chipsets and some other devices.
  451. Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
  452. based hardware IOMMU and a software bounce buffer based IOMMU used
  453. on Intel systems and as fallback.
  454. The code is only active when needed (enough memory and limited
  455. device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
  456. too.
  457. config CALGARY_IOMMU
  458. bool "IBM Calgary IOMMU support"
  459. select SWIOTLB
  460. depends on X86_64 && PCI && EXPERIMENTAL
  461. ---help---
  462. Support for hardware IOMMUs in IBM's xSeries x366 and x460
  463. systems. Needed to run systems with more than 3GB of memory
  464. properly with 32-bit PCI devices that do not support DAC
  465. (Double Address Cycle). Calgary also supports bus level
  466. isolation, where all DMAs pass through the IOMMU. This
  467. prevents them from going anywhere except their intended
  468. destination. This catches hard-to-find kernel bugs and
  469. mis-behaving drivers and devices that do not use the DMA-API
  470. properly to set up their DMA buffers. The IOMMU can be
  471. turned off at boot time with the iommu=off parameter.
  472. Normally the kernel will make the right choice by itself.
  473. If unsure, say Y.
  474. config CALGARY_IOMMU_ENABLED_BY_DEFAULT
  475. def_bool y
  476. prompt "Should Calgary be enabled by default?"
  477. depends on CALGARY_IOMMU
  478. ---help---
  479. Should Calgary be enabled by default? if you choose 'y', Calgary
  480. will be used (if it exists). If you choose 'n', Calgary will not be
  481. used even if it exists. If you choose 'n' and would like to use
  482. Calgary anyway, pass 'iommu=calgary' on the kernel command line.
  483. If unsure, say Y.
  484. config AMD_IOMMU
  485. bool "AMD IOMMU support"
  486. select SWIOTLB
  487. select PCI_MSI
  488. depends on X86_64 && PCI && ACPI
  489. ---help---
  490. With this option you can enable support for AMD IOMMU hardware in
  491. your system. An IOMMU is a hardware component which provides
  492. remapping of DMA memory accesses from devices. With an AMD IOMMU you
  493. can isolate the the DMA memory of different devices and protect the
  494. system from misbehaving device drivers or hardware.
  495. You can find out if your system has an AMD IOMMU if you look into
  496. your BIOS for an option to enable it or if you have an IVRS ACPI
  497. table.
  498. config AMD_IOMMU_STATS
  499. bool "Export AMD IOMMU statistics to debugfs"
  500. depends on AMD_IOMMU
  501. select DEBUG_FS
  502. ---help---
  503. This option enables code in the AMD IOMMU driver to collect various
  504. statistics about whats happening in the driver and exports that
  505. information to userspace via debugfs.
  506. If unsure, say N.
  507. # need this always selected by IOMMU for the VIA workaround
  508. config SWIOTLB
  509. def_bool y if X86_64
  510. ---help---
  511. Support for software bounce buffers used on x86-64 systems
  512. which don't have a hardware IOMMU (e.g. the current generation
  513. of Intel's x86-64 CPUs). Using this PCI devices which can only
  514. access 32-bits of memory can be used on systems with more than
  515. 3 GB of memory. If unsure, say Y.
  516. config IOMMU_HELPER
  517. def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
  518. config IOMMU_API
  519. def_bool (AMD_IOMMU || DMAR)
  520. config MAXSMP
  521. bool "Configure Maximum number of SMP Processors and NUMA Nodes"
  522. depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
  523. select CPUMASK_OFFSTACK
  524. default n
  525. ---help---
  526. Configure maximum number of CPUS and NUMA Nodes for this architecture.
  527. If unsure, say N.
  528. config NR_CPUS
  529. int "Maximum number of CPUs" if SMP && !MAXSMP
  530. range 2 512 if SMP && !MAXSMP
  531. default "1" if !SMP
  532. default "4096" if MAXSMP
  533. default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
  534. default "8" if SMP
  535. ---help---
  536. This allows you to specify the maximum number of CPUs which this
  537. kernel will support. The maximum supported value is 512 and the
  538. minimum value which makes sense is 2.
  539. This is purely to save memory - each supported CPU adds
  540. approximately eight kilobytes to the kernel image.
  541. config SCHED_SMT
  542. bool "SMT (Hyperthreading) scheduler support"
  543. depends on X86_HT
  544. ---help---
  545. SMT scheduler support improves the CPU scheduler's decision making
  546. when dealing with Intel Pentium 4 chips with HyperThreading at a
  547. cost of slightly increased overhead in some places. If unsure say
  548. N here.
  549. config SCHED_MC
  550. def_bool y
  551. prompt "Multi-core scheduler support"
  552. depends on X86_HT
  553. ---help---
  554. Multi-core scheduler support improves the CPU scheduler's decision
  555. making when dealing with multi-core CPU chips at a cost of slightly
  556. increased overhead in some places. If unsure say N here.
  557. source "kernel/Kconfig.preempt"
  558. config X86_UP_APIC
  559. bool "Local APIC support on uniprocessors"
  560. depends on X86_32 && !SMP && !X86_32_NON_STANDARD
  561. ---help---
  562. A local APIC (Advanced Programmable Interrupt Controller) is an
  563. integrated interrupt controller in the CPU. If you have a single-CPU
  564. system which has a processor with a local APIC, you can say Y here to
  565. enable and use it. If you say Y here even though your machine doesn't
  566. have a local APIC, then the kernel will still run with no slowdown at
  567. all. The local APIC supports CPU-generated self-interrupts (timer,
  568. performance counters), and the NMI watchdog which detects hard
  569. lockups.
  570. config X86_UP_IOAPIC
  571. bool "IO-APIC support on uniprocessors"
  572. depends on X86_UP_APIC
  573. ---help---
  574. An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
  575. SMP-capable replacement for PC-style interrupt controllers. Most
  576. SMP systems and many recent uniprocessor systems have one.
  577. If you have a single-CPU system with an IO-APIC, you can say Y here
  578. to use it. If you say Y here even though your machine doesn't have
  579. an IO-APIC, then the kernel will still run with no slowdown at all.
  580. config X86_LOCAL_APIC
  581. def_bool y
  582. depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
  583. config X86_IO_APIC
  584. def_bool y
  585. depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
  586. config X86_VISWS_APIC
  587. def_bool y
  588. depends on X86_32 && X86_VISWS
  589. config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
  590. bool "Reroute for broken boot IRQs"
  591. default n
  592. depends on X86_IO_APIC
  593. ---help---
  594. This option enables a workaround that fixes a source of
  595. spurious interrupts. This is recommended when threaded
  596. interrupt handling is used on systems where the generation of
  597. superfluous "boot interrupts" cannot be disabled.
  598. Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
  599. entry in the chipset's IO-APIC is masked (as, e.g. the RT
  600. kernel does during interrupt handling). On chipsets where this
  601. boot IRQ generation cannot be disabled, this workaround keeps
  602. the original IRQ line masked so that only the equivalent "boot
  603. IRQ" is delivered to the CPUs. The workaround also tells the
  604. kernel to set up the IRQ handler on the boot IRQ line. In this
  605. way only one interrupt is delivered to the kernel. Otherwise
  606. the spurious second interrupt may cause the kernel to bring
  607. down (vital) interrupt lines.
  608. Only affects "broken" chipsets. Interrupt sharing may be
  609. increased on these systems.
  610. config X86_MCE
  611. bool "Machine Check Exception"
  612. ---help---
  613. Machine Check Exception support allows the processor to notify the
  614. kernel if it detects a problem (e.g. overheating, component failure).
  615. The action the kernel takes depends on the severity of the problem,
  616. ranging from a warning message on the console, to halting the machine.
  617. Your processor must be a Pentium or newer to support this - check the
  618. flags in /proc/cpuinfo for mce. Note that some older Pentium systems
  619. have a design flaw which leads to false MCE events - hence MCE is
  620. disabled on all P5 processors, unless explicitly enabled with "mce"
  621. as a boot argument. Similarly, if MCE is built in and creates a
  622. problem on some new non-standard machine, you can boot with "nomce"
  623. to disable it. MCE support simply ignores non-MCE processors like
  624. the 386 and 486, so nearly everyone can say Y here.
  625. config X86_MCE_INTEL
  626. def_bool y
  627. prompt "Intel MCE features"
  628. depends on X86_64 && X86_MCE && X86_LOCAL_APIC
  629. ---help---
  630. Additional support for intel specific MCE features such as
  631. the thermal monitor.
  632. config X86_MCE_AMD
  633. def_bool y
  634. prompt "AMD MCE features"
  635. depends on X86_64 && X86_MCE && X86_LOCAL_APIC
  636. ---help---
  637. Additional support for AMD specific MCE features such as
  638. the DRAM Error Threshold.
  639. config X86_MCE_NONFATAL
  640. tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
  641. depends on X86_32 && X86_MCE
  642. ---help---
  643. Enabling this feature starts a timer that triggers every 5 seconds which
  644. will look at the machine check registers to see if anything happened.
  645. Non-fatal problems automatically get corrected (but still logged).
  646. Disable this if you don't want to see these messages.
  647. Seeing the messages this option prints out may be indicative of dying
  648. or out-of-spec (ie, overclocked) hardware.
  649. This option only does something on certain CPUs.
  650. (AMD Athlon/Duron and Intel Pentium 4)
  651. config X86_MCE_P4THERMAL
  652. bool "check for P4 thermal throttling interrupt."
  653. depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP)
  654. ---help---
  655. Enabling this feature will cause a message to be printed when the P4
  656. enters thermal throttling.
  657. config VM86
  658. bool "Enable VM86 support" if EMBEDDED
  659. default y
  660. depends on X86_32
  661. ---help---
  662. This option is required by programs like DOSEMU to run 16-bit legacy
  663. code on X86 processors. It also may be needed by software like
  664. XFree86 to initialize some video cards via BIOS. Disabling this
  665. option saves about 6k.
  666. config TOSHIBA
  667. tristate "Toshiba Laptop support"
  668. depends on X86_32
  669. ---help---
  670. This adds a driver to safely access the System Management Mode of
  671. the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
  672. not work on models with a Phoenix BIOS. The System Management Mode
  673. is used to set the BIOS and power saving options on Toshiba portables.
  674. For information on utilities to make use of this driver see the
  675. Toshiba Linux utilities web site at:
  676. <http://www.buzzard.org.uk/toshiba/>.
  677. Say Y if you intend to run this kernel on a Toshiba portable.
  678. Say N otherwise.
  679. config I8K
  680. tristate "Dell laptop support"
  681. ---help---
  682. This adds a driver to safely access the System Management Mode
  683. of the CPU on the Dell Inspiron 8000. The System Management Mode
  684. is used to read cpu temperature and cooling fan status and to
  685. control the fans on the I8K portables.
  686. This driver has been tested only on the Inspiron 8000 but it may
  687. also work with other Dell laptops. You can force loading on other
  688. models by passing the parameter `force=1' to the module. Use at
  689. your own risk.
  690. For information on utilities to make use of this driver see the
  691. I8K Linux utilities web site at:
  692. <http://people.debian.org/~dz/i8k/>
  693. Say Y if you intend to run this kernel on a Dell Inspiron 8000.
  694. Say N otherwise.
  695. config X86_REBOOTFIXUPS
  696. bool "Enable X86 board specific fixups for reboot"
  697. depends on X86_32
  698. ---help---
  699. This enables chipset and/or board specific fixups to be done
  700. in order to get reboot to work correctly. This is only needed on
  701. some combinations of hardware and BIOS. The symptom, for which
  702. this config is intended, is when reboot ends with a stalled/hung
  703. system.
  704. Currently, the only fixup is for the Geode machines using
  705. CS5530A and CS5536 chipsets and the RDC R-321x SoC.
  706. Say Y if you want to enable the fixup. Currently, it's safe to
  707. enable this option even if you don't need it.
  708. Say N otherwise.
  709. config MICROCODE
  710. tristate "/dev/cpu/microcode - microcode support"
  711. select FW_LOADER
  712. ---help---
  713. If you say Y here, you will be able to update the microcode on
  714. certain Intel and AMD processors. The Intel support is for the
  715. IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
  716. Pentium 4, Xeon etc. The AMD support is for family 0x10 and
  717. 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
  718. You will obviously need the actual microcode binary data itself
  719. which is not shipped with the Linux kernel.
  720. This option selects the general module only, you need to select
  721. at least one vendor specific module as well.
  722. To compile this driver as a module, choose M here: the
  723. module will be called microcode.
  724. config MICROCODE_INTEL
  725. bool "Intel microcode patch loading support"
  726. depends on MICROCODE
  727. default MICROCODE
  728. select FW_LOADER
  729. ---help---
  730. This options enables microcode patch loading support for Intel
  731. processors.
  732. For latest news and information on obtaining all the required
  733. Intel ingredients for this driver, check:
  734. <http://www.urbanmyth.org/microcode/>.
  735. config MICROCODE_AMD
  736. bool "AMD microcode patch loading support"
  737. depends on MICROCODE
  738. select FW_LOADER
  739. ---help---
  740. If you select this option, microcode patch loading support for AMD
  741. processors will be enabled.
  742. config MICROCODE_OLD_INTERFACE
  743. def_bool y
  744. depends on MICROCODE
  745. config X86_MSR
  746. tristate "/dev/cpu/*/msr - Model-specific register support"
  747. ---help---
  748. This device gives privileged processes access to the x86
  749. Model-Specific Registers (MSRs). It is a character device with
  750. major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
  751. MSR accesses are directed to a specific CPU on multi-processor
  752. systems.
  753. config X86_CPUID
  754. tristate "/dev/cpu/*/cpuid - CPU information support"
  755. ---help---
  756. This device gives processes access to the x86 CPUID instruction to
  757. be executed on a specific processor. It is a character device
  758. with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
  759. /dev/cpu/31/cpuid.
  760. choice
  761. prompt "High Memory Support"
  762. default HIGHMEM4G if !X86_NUMAQ
  763. default HIGHMEM64G if X86_NUMAQ
  764. depends on X86_32
  765. config NOHIGHMEM
  766. bool "off"
  767. depends on !X86_NUMAQ
  768. ---help---
  769. Linux can use up to 64 Gigabytes of physical memory on x86 systems.
  770. However, the address space of 32-bit x86 processors is only 4
  771. Gigabytes large. That means that, if you have a large amount of
  772. physical memory, not all of it can be "permanently mapped" by the
  773. kernel. The physical memory that's not permanently mapped is called
  774. "high memory".
  775. If you are compiling a kernel which will never run on a machine with
  776. more than 1 Gigabyte total physical RAM, answer "off" here (default
  777. choice and suitable for most users). This will result in a "3GB/1GB"
  778. split: 3GB are mapped so that each process sees a 3GB virtual memory
  779. space and the remaining part of the 4GB virtual memory space is used
  780. by the kernel to permanently map as much physical memory as
  781. possible.
  782. If the machine has between 1 and 4 Gigabytes physical RAM, then
  783. answer "4GB" here.
  784. If more than 4 Gigabytes is used then answer "64GB" here. This
  785. selection turns Intel PAE (Physical Address Extension) mode on.
  786. PAE implements 3-level paging on IA32 processors. PAE is fully
  787. supported by Linux, PAE mode is implemented on all recent Intel
  788. processors (Pentium Pro and better). NOTE: If you say "64GB" here,
  789. then the kernel will not boot on CPUs that don't support PAE!
  790. The actual amount of total physical memory will either be
  791. auto detected or can be forced by using a kernel command line option
  792. such as "mem=256M". (Try "man bootparam" or see the documentation of
  793. your boot loader (lilo or loadlin) about how to pass options to the
  794. kernel at boot time.)
  795. If unsure, say "off".
  796. config HIGHMEM4G
  797. bool "4GB"
  798. depends on !X86_NUMAQ
  799. ---help---
  800. Select this if you have a 32-bit processor and between 1 and 4
  801. gigabytes of physical RAM.
  802. config HIGHMEM64G
  803. bool "64GB"
  804. depends on !M386 && !M486
  805. select X86_PAE
  806. ---help---
  807. Select this if you have a 32-bit processor and more than 4
  808. gigabytes of physical RAM.
  809. endchoice
  810. choice
  811. depends on EXPERIMENTAL
  812. prompt "Memory split" if EMBEDDED
  813. default VMSPLIT_3G
  814. depends on X86_32
  815. ---help---
  816. Select the desired split between kernel and user memory.
  817. If the address range available to the kernel is less than the
  818. physical memory installed, the remaining memory will be available
  819. as "high memory". Accessing high memory is a little more costly
  820. than low memory, as it needs to be mapped into the kernel first.
  821. Note that increasing the kernel address space limits the range
  822. available to user programs, making the address space there
  823. tighter. Selecting anything other than the default 3G/1G split
  824. will also likely make your kernel incompatible with binary-only
  825. kernel modules.
  826. If you are not absolutely sure what you are doing, leave this
  827. option alone!
  828. config VMSPLIT_3G
  829. bool "3G/1G user/kernel split"
  830. config VMSPLIT_3G_OPT
  831. depends on !X86_PAE
  832. bool "3G/1G user/kernel split (for full 1G low memory)"
  833. config VMSPLIT_2G
  834. bool "2G/2G user/kernel split"
  835. config VMSPLIT_2G_OPT
  836. depends on !X86_PAE
  837. bool "2G/2G user/kernel split (for full 2G low memory)"
  838. config VMSPLIT_1G
  839. bool "1G/3G user/kernel split"
  840. endchoice
  841. config PAGE_OFFSET
  842. hex
  843. default 0xB0000000 if VMSPLIT_3G_OPT
  844. default 0x80000000 if VMSPLIT_2G
  845. default 0x78000000 if VMSPLIT_2G_OPT
  846. default 0x40000000 if VMSPLIT_1G
  847. default 0xC0000000
  848. depends on X86_32
  849. config HIGHMEM
  850. def_bool y
  851. depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
  852. config X86_PAE
  853. bool "PAE (Physical Address Extension) Support"
  854. depends on X86_32 && !HIGHMEM4G
  855. ---help---
  856. PAE is required for NX support, and furthermore enables
  857. larger swapspace support for non-overcommit purposes. It
  858. has the cost of more pagetable lookup overhead, and also
  859. consumes more pagetable space per process.
  860. config ARCH_PHYS_ADDR_T_64BIT
  861. def_bool X86_64 || X86_PAE
  862. config DIRECT_GBPAGES
  863. bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
  864. default y
  865. depends on X86_64
  866. ---help---
  867. Allow the kernel linear mapping to use 1GB pages on CPUs that
  868. support it. This can improve the kernel's performance a tiny bit by
  869. reducing TLB pressure. If in doubt, say "Y".
  870. # Common NUMA Features
  871. config NUMA
  872. bool "Numa Memory Allocation and Scheduler Support"
  873. depends on SMP
  874. depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
  875. default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
  876. ---help---
  877. Enable NUMA (Non Uniform Memory Access) support.
  878. The kernel will try to allocate memory used by a CPU on the
  879. local memory controller of the CPU and add some more
  880. NUMA awareness to the kernel.
  881. For 64-bit this is recommended if the system is Intel Core i7
  882. (or later), AMD Opteron, or EM64T NUMA.
  883. For 32-bit this is only needed on (rare) 32-bit-only platforms
  884. that support NUMA topologies, such as NUMAQ / Summit, or if you
  885. boot a 32-bit kernel on a 64-bit NUMA platform.
  886. Otherwise, you should say N.
  887. comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
  888. depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
  889. config K8_NUMA
  890. def_bool y
  891. prompt "Old style AMD Opteron NUMA detection"
  892. depends on X86_64 && NUMA && PCI
  893. ---help---
  894. Enable K8 NUMA node topology detection. You should say Y here if
  895. you have a multi processor AMD K8 system. This uses an old
  896. method to read the NUMA configuration directly from the builtin
  897. Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
  898. instead, which also takes priority if both are compiled in.
  899. config X86_64_ACPI_NUMA
  900. def_bool y
  901. prompt "ACPI NUMA detection"
  902. depends on X86_64 && NUMA && ACPI && PCI
  903. select ACPI_NUMA
  904. ---help---
  905. Enable ACPI SRAT based node topology detection.
  906. # Some NUMA nodes have memory ranges that span
  907. # other nodes. Even though a pfn is valid and
  908. # between a node's start and end pfns, it may not
  909. # reside on that node. See memmap_init_zone()
  910. # for details.
  911. config NODES_SPAN_OTHER_NODES
  912. def_bool y
  913. depends on X86_64_ACPI_NUMA
  914. config NUMA_EMU
  915. bool "NUMA emulation"
  916. depends on X86_64 && NUMA
  917. ---help---
  918. Enable NUMA emulation. A flat machine will be split
  919. into virtual nodes when booted with "numa=fake=N", where N is the
  920. number of nodes. This is only useful for debugging.
  921. config NODES_SHIFT
  922. int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
  923. range 1 9 if X86_64
  924. default "9" if MAXSMP
  925. default "6" if X86_64
  926. default "4" if X86_NUMAQ
  927. default "3"
  928. depends on NEED_MULTIPLE_NODES
  929. ---help---
  930. Specify the maximum number of NUMA Nodes available on the target
  931. system. Increases memory reserved to accomodate various tables.
  932. config HAVE_ARCH_BOOTMEM_NODE
  933. def_bool y
  934. depends on X86_32 && NUMA
  935. config ARCH_HAVE_MEMORY_PRESENT
  936. def_bool y
  937. depends on X86_32 && DISCONTIGMEM
  938. config NEED_NODE_MEMMAP_SIZE
  939. def_bool y
  940. depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
  941. config HAVE_ARCH_ALLOC_REMAP
  942. def_bool y
  943. depends on X86_32 && NUMA
  944. config ARCH_FLATMEM_ENABLE
  945. def_bool y
  946. depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
  947. config ARCH_DISCONTIGMEM_ENABLE
  948. def_bool y
  949. depends on NUMA && X86_32
  950. config ARCH_DISCONTIGMEM_DEFAULT
  951. def_bool y
  952. depends on NUMA && X86_32
  953. config ARCH_SPARSEMEM_DEFAULT
  954. def_bool y
  955. depends on X86_64
  956. config ARCH_SPARSEMEM_ENABLE
  957. def_bool y
  958. depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
  959. select SPARSEMEM_STATIC if X86_32
  960. select SPARSEMEM_VMEMMAP_ENABLE if X86_64
  961. config ARCH_SELECT_MEMORY_MODEL
  962. def_bool y
  963. depends on ARCH_SPARSEMEM_ENABLE
  964. config ARCH_MEMORY_PROBE
  965. def_bool X86_64
  966. depends on MEMORY_HOTPLUG
  967. source "mm/Kconfig"
  968. config HIGHPTE
  969. bool "Allocate 3rd-level pagetables from highmem"
  970. depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
  971. ---help---
  972. The VM uses one page table entry for each page of physical memory.
  973. For systems with a lot of RAM, this can be wasteful of precious
  974. low memory. Setting this option will put user-space page table
  975. entries in high memory.
  976. config X86_CHECK_BIOS_CORRUPTION
  977. bool "Check for low memory corruption"
  978. ---help---
  979. Periodically check for memory corruption in low memory, which
  980. is suspected to be caused by BIOS. Even when enabled in the
  981. configuration, it is disabled at runtime. Enable it by
  982. setting "memory_corruption_check=1" on the kernel command
  983. line. By default it scans the low 64k of memory every 60
  984. seconds; see the memory_corruption_check_size and
  985. memory_corruption_check_period parameters in
  986. Documentation/kernel-parameters.txt to adjust this.
  987. When enabled with the default parameters, this option has
  988. almost no overhead, as it reserves a relatively small amount
  989. of memory and scans it infrequently. It both detects corruption
  990. and prevents it from affecting the running system.
  991. It is, however, intended as a diagnostic tool; if repeatable
  992. BIOS-originated corruption always affects the same memory,
  993. you can use memmap= to prevent the kernel from using that
  994. memory.
  995. config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
  996. bool "Set the default setting of memory_corruption_check"
  997. depends on X86_CHECK_BIOS_CORRUPTION
  998. default y
  999. ---help---
  1000. Set whether the default state of memory_corruption_check is
  1001. on or off.
  1002. config X86_RESERVE_LOW_64K
  1003. bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
  1004. default y
  1005. ---help---
  1006. Reserve the first 64K of physical RAM on BIOSes that are known
  1007. to potentially corrupt that memory range. A numbers of BIOSes are
  1008. known to utilize this area during suspend/resume, so it must not
  1009. be used by the kernel.
  1010. Set this to N if you are absolutely sure that you trust the BIOS
  1011. to get all its memory reservations and usages right.
  1012. If you have doubts about the BIOS (e.g. suspend/resume does not
  1013. work or there's kernel crashes after certain hardware hotplug
  1014. events) and it's not AMI or Phoenix, then you might want to enable
  1015. X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
  1016. corruption patterns.
  1017. Say Y if unsure.
  1018. config MATH_EMULATION
  1019. bool
  1020. prompt "Math emulation" if X86_32
  1021. ---help---
  1022. Linux can emulate a math coprocessor (used for floating point
  1023. operations) if you don't have one. 486DX and Pentium processors have
  1024. a math coprocessor built in, 486SX and 386 do not, unless you added
  1025. a 487DX or 387, respectively. (The messages during boot time can
  1026. give you some hints here ["man dmesg"].) Everyone needs either a
  1027. coprocessor or this emulation.
  1028. If you don't have a math coprocessor, you need to say Y here; if you
  1029. say Y here even though you have a coprocessor, the coprocessor will
  1030. be used nevertheless. (This behavior can be changed with the kernel
  1031. command line option "no387", which comes handy if your coprocessor
  1032. is broken. Try "man bootparam" or see the documentation of your boot
  1033. loader (lilo or loadlin) about how to pass options to the kernel at
  1034. boot time.) This means that it is a good idea to say Y here if you
  1035. intend to use this kernel on different machines.
  1036. More information about the internals of the Linux math coprocessor
  1037. emulation can be found in <file:arch/x86/math-emu/README>.
  1038. If you are not sure, say Y; apart from resulting in a 66 KB bigger
  1039. kernel, it won't hurt.
  1040. config MTRR
  1041. bool "MTRR (Memory Type Range Register) support"
  1042. ---help---
  1043. On Intel P6 family processors (Pentium Pro, Pentium II and later)
  1044. the Memory Type Range Registers (MTRRs) may be used to control
  1045. processor access to memory ranges. This is most useful if you have
  1046. a video (VGA) card on a PCI or AGP bus. Enabling write-combining
  1047. allows bus write transfers to be combined into a larger transfer
  1048. before bursting over the PCI/AGP bus. This can increase performance
  1049. of image write operations 2.5 times or more. Saying Y here creates a
  1050. /proc/mtrr file which may be used to manipulate your processor's
  1051. MTRRs. Typically the X server should use this.
  1052. This code has a reasonably generic interface so that similar
  1053. control registers on other processors can be easily supported
  1054. as well:
  1055. The Cyrix 6x86, 6x86MX and M II processors have Address Range
  1056. Registers (ARRs) which provide a similar functionality to MTRRs. For
  1057. these, the ARRs are used to emulate the MTRRs.
  1058. The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
  1059. MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
  1060. write-combining. All of these processors are supported by this code
  1061. and it makes sense to say Y here if you have one of them.
  1062. Saying Y here also fixes a problem with buggy SMP BIOSes which only
  1063. set the MTRRs for the boot CPU and not for the secondary CPUs. This
  1064. can lead to all sorts of problems, so it's good to say Y here.
  1065. You can safely say Y even if your machine doesn't have MTRRs, you'll
  1066. just add about 9 KB to your kernel.
  1067. See <file:Documentation/x86/mtrr.txt> for more information.
  1068. config MTRR_SANITIZER
  1069. def_bool y
  1070. prompt "MTRR cleanup support"
  1071. depends on MTRR
  1072. ---help---
  1073. Convert MTRR layout from continuous to discrete, so X drivers can
  1074. add writeback entries.
  1075. Can be disabled with disable_mtrr_cleanup on the kernel command line.
  1076. The largest mtrr entry size for a continous block can be set with
  1077. mtrr_chunk_size.
  1078. If unsure, say Y.
  1079. config MTRR_SANITIZER_ENABLE_DEFAULT
  1080. int "MTRR cleanup enable value (0-1)"
  1081. range 0 1
  1082. default "0"
  1083. depends on MTRR_SANITIZER
  1084. ---help---
  1085. Enable mtrr cleanup default value
  1086. config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
  1087. int "MTRR cleanup spare reg num (0-7)"
  1088. range 0 7
  1089. default "1"
  1090. depends on MTRR_SANITIZER
  1091. ---help---
  1092. mtrr cleanup spare entries default, it can be changed via
  1093. mtrr_spare_reg_nr=N on the kernel command line.
  1094. config X86_PAT
  1095. bool
  1096. prompt "x86 PAT support"
  1097. depends on MTRR
  1098. ---help---
  1099. Use PAT attributes to setup page level cache control.
  1100. PATs are the modern equivalents of MTRRs and are much more
  1101. flexible than MTRRs.
  1102. Say N here if you see bootup problems (boot crash, boot hang,
  1103. spontaneous reboots) or a non-working video driver.
  1104. If unsure, say Y.
  1105. config EFI
  1106. bool "EFI runtime service support"
  1107. depends on ACPI
  1108. ---help---
  1109. This enables the kernel to use EFI runtime services that are
  1110. available (such as the EFI variable services).
  1111. This option is only useful on systems that have EFI firmware.
  1112. In addition, you should use the latest ELILO loader available
  1113. at <http://elilo.sourceforge.net> in order to take advantage
  1114. of EFI runtime services. However, even with this option, the
  1115. resultant kernel should continue to boot on existing non-EFI
  1116. platforms.
  1117. config SECCOMP
  1118. def_bool y
  1119. prompt "Enable seccomp to safely compute untrusted bytecode"
  1120. ---help---
  1121. This kernel feature is useful for number crunching applications
  1122. that may need to compute untrusted bytecode during their
  1123. execution. By using pipes or other transports made available to
  1124. the process as file descriptors supporting the read/write
  1125. syscalls, it's possible to isolate those applications in
  1126. their own address space using seccomp. Once seccomp is
  1127. enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
  1128. and the task is only allowed to execute a few safe syscalls
  1129. defined by each seccomp mode.
  1130. If unsure, say Y. Only embedded should say N here.
  1131. config CC_STACKPROTECTOR_ALL
  1132. bool
  1133. config CC_STACKPROTECTOR
  1134. bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
  1135. select CC_STACKPROTECTOR_ALL
  1136. ---help---
  1137. This option turns on the -fstack-protector GCC feature. This
  1138. feature puts, at the beginning of functions, a canary value on
  1139. the stack just before the return address, and validates
  1140. the value just before actually returning. Stack based buffer
  1141. overflows (that need to overwrite this return address) now also
  1142. overwrite the canary, which gets detected and the attack is then
  1143. neutralized via a kernel panic.
  1144. This feature requires gcc version 4.2 or above, or a distribution
  1145. gcc with the feature backported. Older versions are automatically
  1146. detected and for those versions, this configuration option is
  1147. ignored. (and a warning is printed during bootup)
  1148. source kernel/Kconfig.hz
  1149. config KEXEC
  1150. bool "kexec system call"
  1151. ---help---
  1152. kexec is a system call that implements the ability to shutdown your
  1153. current kernel, and to start another kernel. It is like a reboot
  1154. but it is independent of the system firmware. And like a reboot
  1155. you can start any kernel with it, not just Linux.
  1156. The name comes from the similarity to the exec system call.
  1157. It is an ongoing process to be certain the hardware in a machine
  1158. is properly shutdown, so do not be surprised if this code does not
  1159. initially work for you. It may help to enable device hotplugging
  1160. support. As of this writing the exact hardware interface is
  1161. strongly in flux, so no good recommendation can be made.
  1162. config CRASH_DUMP
  1163. bool "kernel crash dumps"
  1164. depends on X86_64 || (X86_32 && HIGHMEM)
  1165. ---help---
  1166. Generate crash dump after being started by kexec.
  1167. This should be normally only set in special crash dump kernels
  1168. which are loaded in the main kernel with kexec-tools into
  1169. a specially reserved region and then later executed after
  1170. a crash by kdump/kexec. The crash dump kernel must be compiled
  1171. to a memory address not used by the main kernel or BIOS using
  1172. PHYSICAL_START, or it must be built as a relocatable image
  1173. (CONFIG_RELOCATABLE=y).
  1174. For more details see Documentation/kdump/kdump.txt
  1175. config KEXEC_JUMP
  1176. bool "kexec jump (EXPERIMENTAL)"
  1177. depends on EXPERIMENTAL
  1178. depends on KEXEC && HIBERNATION && X86_32
  1179. ---help---
  1180. Jump between original kernel and kexeced kernel and invoke
  1181. code in physical address mode via KEXEC
  1182. config PHYSICAL_START
  1183. hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
  1184. default "0x1000000" if X86_NUMAQ
  1185. default "0x200000" if X86_64
  1186. default "0x100000"
  1187. ---help---
  1188. This gives the physical address where the kernel is loaded.
  1189. If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
  1190. bzImage will decompress itself to above physical address and
  1191. run from there. Otherwise, bzImage will run from the address where
  1192. it has been loaded by the boot loader and will ignore above physical
  1193. address.
  1194. In normal kdump cases one does not have to set/change this option
  1195. as now bzImage can be compiled as a completely relocatable image
  1196. (CONFIG_RELOCATABLE=y) and be used to load and run from a different
  1197. address. This option is mainly useful for the folks who don't want
  1198. to use a bzImage for capturing the crash dump and want to use a
  1199. vmlinux instead. vmlinux is not relocatable hence a kernel needs
  1200. to be specifically compiled to run from a specific memory area
  1201. (normally a reserved region) and this option comes handy.
  1202. So if you are using bzImage for capturing the crash dump, leave
  1203. the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
  1204. Otherwise if you plan to use vmlinux for capturing the crash dump
  1205. change this value to start of the reserved region (Typically 16MB
  1206. 0x1000000). In other words, it can be set based on the "X" value as
  1207. specified in the "crashkernel=YM@XM" command line boot parameter
  1208. passed to the panic-ed kernel. Typically this parameter is set as
  1209. crashkernel=64M@16M. Please take a look at
  1210. Documentation/kdump/kdump.txt for more details about crash dumps.
  1211. Usage of bzImage for capturing the crash dump is recommended as
  1212. one does not have to build two kernels. Same kernel can be used
  1213. as production kernel and capture kernel. Above option should have
  1214. gone away after relocatable bzImage support is introduced. But it
  1215. is present because there are users out there who continue to use
  1216. vmlinux for dump capture. This option should go away down the
  1217. line.
  1218. Don't change this unless you know what you are doing.
  1219. config RELOCATABLE
  1220. bool "Build a relocatable kernel (EXPERIMENTAL)"
  1221. depends on EXPERIMENTAL
  1222. ---help---
  1223. This builds a kernel image that retains relocation information
  1224. so it can be loaded someplace besides the default 1MB.
  1225. The relocations tend to make the kernel binary about 10% larger,
  1226. but are discarded at runtime.
  1227. One use is for the kexec on panic case where the recovery kernel
  1228. must live at a different physical address than the primary
  1229. kernel.
  1230. Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
  1231. it has been loaded at and the compile time physical address
  1232. (CONFIG_PHYSICAL_START) is ignored.
  1233. config PHYSICAL_ALIGN
  1234. hex
  1235. prompt "Alignment value to which kernel should be aligned" if X86_32
  1236. default "0x100000" if X86_32
  1237. default "0x200000" if X86_64
  1238. range 0x2000 0x400000
  1239. ---help---
  1240. This value puts the alignment restrictions on physical address
  1241. where kernel is loaded and run from. Kernel is compiled for an
  1242. address which meets above alignment restriction.
  1243. If bootloader loads the kernel at a non-aligned address and
  1244. CONFIG_RELOCATABLE is set, kernel will move itself to nearest
  1245. address aligned to above value and run from there.
  1246. If bootloader loads the kernel at a non-aligned address and
  1247. CONFIG_RELOCATABLE is not set, kernel will ignore the run time
  1248. load address and decompress itself to the address it has been
  1249. compiled for and run from there. The address for which kernel is
  1250. compiled already meets above alignment restrictions. Hence the
  1251. end result is that kernel runs from a physical address meeting
  1252. above alignment restrictions.
  1253. Don't change this unless you know what you are doing.
  1254. config HOTPLUG_CPU
  1255. bool "Support for hot-pluggable CPUs"
  1256. depends on SMP && HOTPLUG
  1257. ---help---
  1258. Say Y here to allow turning CPUs off and on. CPUs can be
  1259. controlled through /sys/devices/system/cpu.
  1260. ( Note: power management support will enable this option
  1261. automatically on SMP systems. )
  1262. Say N if you want to disable CPU hotplug.
  1263. config COMPAT_VDSO
  1264. def_bool y
  1265. prompt "Compat VDSO support"
  1266. depends on X86_32 || IA32_EMULATION
  1267. ---help---
  1268. Map the 32-bit VDSO to the predictable old-style address too.
  1269. ---help---
  1270. Say N here if you are running a sufficiently recent glibc
  1271. version (2.3.3 or later), to remove the high-mapped
  1272. VDSO mapping and to exclusively use the randomized VDSO.
  1273. If unsure, say Y.
  1274. config CMDLINE_BOOL
  1275. bool "Built-in kernel command line"
  1276. default n
  1277. ---help---
  1278. Allow for specifying boot arguments to the kernel at
  1279. build time. On some systems (e.g. embedded ones), it is
  1280. necessary or convenient to provide some or all of the
  1281. kernel boot arguments with the kernel itself (that is,
  1282. to not rely on the boot loader to provide them.)
  1283. To compile command line arguments into the kernel,
  1284. set this option to 'Y', then fill in the
  1285. the boot arguments in CONFIG_CMDLINE.
  1286. Systems with fully functional boot loaders (i.e. non-embedded)
  1287. should leave this option set to 'N'.
  1288. config CMDLINE
  1289. string "Built-in kernel command string"
  1290. depends on CMDLINE_BOOL
  1291. default ""
  1292. ---help---
  1293. Enter arguments here that should be compiled into the kernel
  1294. image and used at boot time. If the boot loader provides a
  1295. command line at boot time, it is appended to this string to
  1296. form the full kernel command line, when the system boots.
  1297. However, you can use the CONFIG_CMDLINE_OVERRIDE option to
  1298. change this behavior.
  1299. In most cases, the command line (whether built-in or provided
  1300. by the boot loader) should specify the device for the root
  1301. file system.
  1302. config CMDLINE_OVERRIDE
  1303. bool "Built-in command line overrides boot loader arguments"
  1304. default n
  1305. depends on CMDLINE_BOOL
  1306. ---help---
  1307. Set this option to 'Y' to have the kernel ignore the boot loader
  1308. command line, and use ONLY the built-in command line.
  1309. This is used to work around broken boot loaders. This should
  1310. be set to 'N' under normal conditions.
  1311. endmenu
  1312. config ARCH_ENABLE_MEMORY_HOTPLUG
  1313. def_bool y
  1314. depends on X86_64 || (X86_32 && HIGHMEM)
  1315. config ARCH_ENABLE_MEMORY_HOTREMOVE
  1316. def_bool y
  1317. depends on MEMORY_HOTPLUG
  1318. config HAVE_ARCH_EARLY_PFN_TO_NID
  1319. def_bool X86_64
  1320. depends on NUMA
  1321. menu "Power management and ACPI options"
  1322. config ARCH_HIBERNATION_HEADER
  1323. def_bool y
  1324. depends on X86_64 && HIBERNATION
  1325. source "kernel/power/Kconfig"
  1326. source "drivers/acpi/Kconfig"
  1327. config X86_APM_BOOT
  1328. bool
  1329. default y
  1330. depends on APM || APM_MODULE
  1331. menuconfig APM
  1332. tristate "APM (Advanced Power Management) BIOS support"
  1333. depends on X86_32 && PM_SLEEP
  1334. ---help---
  1335. APM is a BIOS specification for saving power using several different
  1336. techniques. This is mostly useful for battery powered laptops with
  1337. APM compliant BIOSes. If you say Y here, the system time will be
  1338. reset after a RESUME operation, the /proc/apm device will provide
  1339. battery status information, and user-space programs will receive
  1340. notification of APM "events" (e.g. battery status change).
  1341. If you select "Y" here, you can disable actual use of the APM
  1342. BIOS by passing the "apm=off" option to the kernel at boot time.
  1343. Note that the APM support is almost completely disabled for
  1344. machines with more than one CPU.
  1345. In order to use APM, you will need supporting software. For location
  1346. and more information, read <file:Documentation/power/pm.txt> and the
  1347. Battery Powered Linux mini-HOWTO, available from
  1348. <http://www.tldp.org/docs.html#howto>.
  1349. This driver does not spin down disk drives (see the hdparm(8)
  1350. manpage ("man 8 hdparm") for that), and it doesn't turn off
  1351. VESA-compliant "green" monitors.
  1352. This driver does not support the TI 4000M TravelMate and the ACER
  1353. 486/DX4/75 because they don't have compliant BIOSes. Many "green"
  1354. desktop machines also don't have compliant BIOSes, and this driver
  1355. may cause those machines to panic during the boot phase.
  1356. Generally, if you don't have a battery in your machine, there isn't
  1357. much point in using this driver and you should say N. If you get
  1358. random kernel OOPSes or reboots that don't seem to be related to
  1359. anything, try disabling/enabling this option (or disabling/enabling
  1360. APM in your BIOS).
  1361. Some other things you should try when experiencing seemingly random,
  1362. "weird" problems:
  1363. 1) make sure that you have enough swap space and that it is
  1364. enabled.
  1365. 2) pass the "no-hlt" option to the kernel
  1366. 3) switch on floating point emulation in the kernel and pass
  1367. the "no387" option to the kernel
  1368. 4) pass the "floppy=nodma" option to the kernel
  1369. 5) pass the "mem=4M" option to the kernel (thereby disabling
  1370. all but the first 4 MB of RAM)
  1371. 6) make sure that the CPU is not over clocked.
  1372. 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
  1373. 8) disable the cache from your BIOS settings
  1374. 9) install a fan for the video card or exchange video RAM
  1375. 10) install a better fan for the CPU
  1376. 11) exchange RAM chips
  1377. 12) exchange the motherboard.
  1378. To compile this driver as a module, choose M here: the
  1379. module will be called apm.
  1380. if APM
  1381. config APM_IGNORE_USER_SUSPEND
  1382. bool "Ignore USER SUSPEND"
  1383. ---help---
  1384. This option will ignore USER SUSPEND requests. On machines with a
  1385. compliant APM BIOS, you want to say N. However, on the NEC Versa M
  1386. series notebooks, it is necessary to say Y because of a BIOS bug.
  1387. config APM_DO_ENABLE
  1388. bool "Enable PM at boot time"
  1389. ---help---
  1390. Enable APM features at boot time. From page 36 of the APM BIOS
  1391. specification: "When disabled, the APM BIOS does not automatically
  1392. power manage devices, enter the Standby State, enter the Suspend
  1393. State, or take power saving steps in response to CPU Idle calls."
  1394. This driver will make CPU Idle calls when Linux is idle (unless this
  1395. feature is turned off -- see "Do CPU IDLE calls", below). This
  1396. should always save battery power, but more complicated APM features
  1397. will be dependent on your BIOS implementation. You may need to turn
  1398. this option off if your computer hangs at boot time when using APM
  1399. support, or if it beeps continuously instead of suspending. Turn
  1400. this off if you have a NEC UltraLite Versa 33/C or a Toshiba
  1401. T400CDT. This is off by default since most machines do fine without
  1402. this feature.
  1403. config APM_CPU_IDLE
  1404. bool "Make CPU Idle calls when idle"
  1405. ---help---
  1406. Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
  1407. On some machines, this can activate improved power savings, such as
  1408. a slowed CPU clock rate, when the machine is idle. These idle calls
  1409. are made after the idle loop has run for some length of time (e.g.,
  1410. 333 mS). On some machines, this will cause a hang at boot time or
  1411. whenever the CPU becomes idle. (On machines with more than one CPU,
  1412. this option does nothing.)
  1413. config APM_DISPLAY_BLANK
  1414. bool "Enable console blanking using APM"
  1415. ---help---
  1416. Enable console blanking using the APM. Some laptops can use this to
  1417. turn off the LCD backlight when the screen blanker of the Linux
  1418. virtual console blanks the screen. Note that this is only used by
  1419. the virtual console screen blanker, and won't turn off the backlight
  1420. when using the X Window system. This also doesn't have anything to
  1421. do with your VESA-compliant power-saving monitor. Further, this
  1422. option doesn't work for all laptops -- it might not turn off your
  1423. backlight at all, or it might print a lot of errors to the console,
  1424. especially if you are using gpm.
  1425. config APM_ALLOW_INTS
  1426. bool "Allow interrupts during APM BIOS calls"
  1427. ---help---
  1428. Normally we disable external interrupts while we are making calls to
  1429. the APM BIOS as a measure to lessen the effects of a badly behaving
  1430. BIOS implementation. The BIOS should reenable interrupts if it
  1431. needs to. Unfortunately, some BIOSes do not -- especially those in
  1432. many of the newer IBM Thinkpads. If you experience hangs when you
  1433. suspend, try setting this to Y. Otherwise, say N.
  1434. endif # APM
  1435. source "arch/x86/kernel/cpu/cpufreq/Kconfig"
  1436. source "drivers/cpuidle/Kconfig"
  1437. source "drivers/idle/Kconfig"
  1438. endmenu
  1439. menu "Bus options (PCI etc.)"
  1440. config PCI
  1441. bool "PCI support"
  1442. default y
  1443. select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
  1444. ---help---
  1445. Find out whether you have a PCI motherboard. PCI is the name of a
  1446. bus system, i.e. the way the CPU talks to the other stuff inside
  1447. your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
  1448. VESA. If you have PCI, say Y, otherwise N.
  1449. choice
  1450. prompt "PCI access mode"
  1451. depends on X86_32 && PCI
  1452. default PCI_GOANY
  1453. ---help---
  1454. On PCI systems, the BIOS can be used to detect the PCI devices and
  1455. determine their configuration. However, some old PCI motherboards
  1456. have BIOS bugs and may crash if this is done. Also, some embedded
  1457. PCI-based systems don't have any BIOS at all. Linux can also try to
  1458. detect the PCI hardware directly without using the BIOS.
  1459. With this option, you can specify how Linux should detect the
  1460. PCI devices. If you choose "BIOS", the BIOS will be used,
  1461. if you choose "Direct", the BIOS won't be used, and if you
  1462. choose "MMConfig", then PCI Express MMCONFIG will be used.
  1463. If you choose "Any", the kernel will try MMCONFIG, then the
  1464. direct access method and falls back to the BIOS if that doesn't
  1465. work. If unsure, go with the default, which is "Any".
  1466. config PCI_GOBIOS
  1467. bool "BIOS"
  1468. config PCI_GOMMCONFIG
  1469. bool "MMConfig"
  1470. config PCI_GODIRECT
  1471. bool "Direct"
  1472. config PCI_GOOLPC
  1473. bool "OLPC"
  1474. depends on OLPC
  1475. config PCI_GOANY
  1476. bool "Any"
  1477. endchoice
  1478. config PCI_BIOS
  1479. def_bool y
  1480. depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
  1481. # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
  1482. config PCI_DIRECT
  1483. def_bool y
  1484. depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
  1485. config PCI_MMCONFIG
  1486. def_bool y
  1487. depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
  1488. config PCI_OLPC
  1489. def_bool y
  1490. depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
  1491. config PCI_DOMAINS
  1492. def_bool y
  1493. depends on PCI
  1494. config PCI_MMCONFIG
  1495. bool "Support mmconfig PCI config space access"
  1496. depends on X86_64 && PCI && ACPI
  1497. config DMAR
  1498. bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
  1499. depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
  1500. ---help---
  1501. DMA remapping (DMAR) devices support enables independent address
  1502. translations for Direct Memory Access (DMA) from devices.
  1503. These DMA remapping devices are reported via ACPI tables
  1504. and include PCI device scope covered by these DMA
  1505. remapping devices.
  1506. config DMAR_DEFAULT_ON
  1507. def_bool n
  1508. prompt "Enable DMA Remapping Devices by default"
  1509. depends on DMAR
  1510. help
  1511. Selecting this option will enable a DMAR device at boot time if
  1512. one is found. If this option is not selected, DMAR support can
  1513. be enabled by passing intel_iommu=on to the kernel. It is
  1514. recommended you say N here while the DMAR code remains
  1515. experimental.
  1516. config DMAR_GFX_WA
  1517. def_bool y
  1518. prompt "Support for Graphics workaround"
  1519. depends on DMAR
  1520. ---help---
  1521. Current Graphics drivers tend to use physical address
  1522. for DMA and avoid using DMA APIs. Setting this config
  1523. option permits the IOMMU driver to set a unity map for
  1524. all the OS-visible memory. Hence the driver can continue
  1525. to use physical addresses for DMA.
  1526. config DMAR_FLOPPY_WA
  1527. def_bool y
  1528. depends on DMAR
  1529. ---help---
  1530. Floppy disk drivers are know to bypass DMA API calls
  1531. thereby failing to work when IOMMU is enabled. This
  1532. workaround will setup a 1:1 mapping for the first
  1533. 16M to make floppy (an ISA device) work.
  1534. config INTR_REMAP
  1535. bool "Support for Interrupt Remapping (EXPERIMENTAL)"
  1536. depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
  1537. select X86_X2APIC
  1538. ---help---
  1539. Supports Interrupt remapping for IO-APIC and MSI devices.
  1540. To use x2apic mode in the CPU's which support x2APIC enhancements or
  1541. to support platforms with CPU's having > 8 bit APIC ID, say Y.
  1542. source "drivers/pci/pcie/Kconfig"
  1543. source "drivers/pci/Kconfig"
  1544. # x86_64 have no ISA slots, but do have ISA-style DMA.
  1545. config ISA_DMA_API
  1546. def_bool y
  1547. if X86_32
  1548. config ISA
  1549. bool "ISA support"
  1550. ---help---
  1551. Find out whether you have ISA slots on your motherboard. ISA is the
  1552. name of a bus system, i.e. the way the CPU talks to the other stuff
  1553. inside your box. Other bus systems are PCI, EISA, MicroChannel
  1554. (MCA) or VESA. ISA is an older system, now being displaced by PCI;
  1555. newer boards don't support it. If you have ISA, say Y, otherwise N.
  1556. config EISA
  1557. bool "EISA support"
  1558. depends on ISA
  1559. ---help---
  1560. The Extended Industry Standard Architecture (EISA) bus was
  1561. developed as an open alternative to the IBM MicroChannel bus.
  1562. The EISA bus provided some of the features of the IBM MicroChannel
  1563. bus while maintaining backward compatibility with cards made for
  1564. the older ISA bus. The EISA bus saw limited use between 1988 and
  1565. 1995 when it was made obsolete by the PCI bus.
  1566. Say Y here if you are building a kernel for an EISA-based machine.
  1567. Otherwise, say N.
  1568. source "drivers/eisa/Kconfig"
  1569. config MCA
  1570. bool "MCA support"
  1571. ---help---
  1572. MicroChannel Architecture is found in some IBM PS/2 machines and
  1573. laptops. It is a bus system similar to PCI or ISA. See
  1574. <file:Documentation/mca.txt> (and especially the web page given
  1575. there) before attempting to build an MCA bus kernel.
  1576. source "drivers/mca/Kconfig"
  1577. config SCx200
  1578. tristate "NatSemi SCx200 support"
  1579. ---help---
  1580. This provides basic support for National Semiconductor's
  1581. (now AMD's) Geode processors. The driver probes for the
  1582. PCI-IDs of several on-chip devices, so its a good dependency
  1583. for other scx200_* drivers.
  1584. If compiled as a module, the driver is named scx200.
  1585. config SCx200HR_TIMER
  1586. tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
  1587. depends on SCx200 && GENERIC_TIME
  1588. default y
  1589. ---help---
  1590. This driver provides a clocksource built upon the on-chip
  1591. 27MHz high-resolution timer. Its also a workaround for
  1592. NSC Geode SC-1100's buggy TSC, which loses time when the
  1593. processor goes idle (as is done by the scheduler). The
  1594. other workaround is idle=poll boot option.
  1595. config GEODE_MFGPT_TIMER
  1596. def_bool y
  1597. prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
  1598. depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
  1599. ---help---
  1600. This driver provides a clock event source based on the MFGPT
  1601. timer(s) in the CS5535 and CS5536 companion chip for the geode.
  1602. MFGPTs have a better resolution and max interval than the
  1603. generic PIT, and are suitable for use as high-res timers.
  1604. config OLPC
  1605. bool "One Laptop Per Child support"
  1606. default n
  1607. ---help---
  1608. Add support for detecting the unique features of the OLPC
  1609. XO hardware.
  1610. endif # X86_32
  1611. config K8_NB
  1612. def_bool y
  1613. depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
  1614. source "drivers/pcmcia/Kconfig"
  1615. source "drivers/pci/hotplug/Kconfig"
  1616. endmenu
  1617. menu "Executable file formats / Emulations"
  1618. source "fs/Kconfig.binfmt"
  1619. config IA32_EMULATION
  1620. bool "IA32 Emulation"
  1621. depends on X86_64
  1622. select COMPAT_BINFMT_ELF
  1623. ---help---
  1624. Include code to run 32-bit programs under a 64-bit kernel. You should
  1625. likely turn this on, unless you're 100% sure that you don't have any
  1626. 32-bit programs left.
  1627. config IA32_AOUT
  1628. tristate "IA32 a.out support"
  1629. depends on IA32_EMULATION
  1630. ---help---
  1631. Support old a.out binaries in the 32bit emulation.
  1632. config COMPAT
  1633. def_bool y
  1634. depends on IA32_EMULATION
  1635. config COMPAT_FOR_U64_ALIGNMENT
  1636. def_bool COMPAT
  1637. depends on X86_64
  1638. config SYSVIPC_COMPAT
  1639. def_bool y
  1640. depends on COMPAT && SYSVIPC
  1641. endmenu
  1642. config HAVE_ATOMIC_IOMAP
  1643. def_bool y
  1644. depends on X86_32
  1645. source "net/Kconfig"
  1646. source "drivers/Kconfig"
  1647. source "drivers/firmware/Kconfig"
  1648. source "fs/Kconfig"
  1649. source "arch/x86/Kconfig.debug"
  1650. source "security/Kconfig"
  1651. source "crypto/Kconfig"
  1652. source "arch/x86/kvm/Kconfig"
  1653. source "lib/Kconfig"