Kconfig 67 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_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
  34. select HAVE_FTRACE_SYSCALLS
  35. select HAVE_KVM
  36. select HAVE_ARCH_KGDB
  37. select HAVE_ARCH_TRACEHOOK
  38. select HAVE_GENERIC_DMA_COHERENT if X86_32
  39. select HAVE_EFFICIENT_UNALIGNED_ACCESS
  40. select USER_STACKTRACE_SUPPORT
  41. select HAVE_DMA_API_DEBUG
  42. select HAVE_KERNEL_GZIP
  43. select HAVE_KERNEL_BZIP2
  44. select HAVE_KERNEL_LZMA
  45. config ARCH_DEFCONFIG
  46. string
  47. default "arch/x86/configs/i386_defconfig" if X86_32
  48. default "arch/x86/configs/x86_64_defconfig" if X86_64
  49. config GENERIC_TIME
  50. def_bool y
  51. config GENERIC_CMOS_UPDATE
  52. def_bool y
  53. config CLOCKSOURCE_WATCHDOG
  54. def_bool y
  55. config GENERIC_CLOCKEVENTS
  56. def_bool y
  57. config GENERIC_CLOCKEVENTS_BROADCAST
  58. def_bool y
  59. depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
  60. config LOCKDEP_SUPPORT
  61. def_bool y
  62. config STACKTRACE_SUPPORT
  63. def_bool y
  64. config HAVE_LATENCYTOP_SUPPORT
  65. def_bool y
  66. config FAST_CMPXCHG_LOCAL
  67. bool
  68. default y
  69. config MMU
  70. def_bool y
  71. config ZONE_DMA
  72. def_bool y
  73. config SBUS
  74. bool
  75. config GENERIC_ISA_DMA
  76. def_bool y
  77. config GENERIC_IOMAP
  78. def_bool y
  79. config GENERIC_BUG
  80. def_bool y
  81. depends on BUG
  82. select GENERIC_BUG_RELATIVE_POINTERS if X86_64
  83. config GENERIC_BUG_RELATIVE_POINTERS
  84. bool
  85. config GENERIC_HWEIGHT
  86. def_bool y
  87. config GENERIC_GPIO
  88. bool
  89. config ARCH_MAY_HAVE_PC_FDC
  90. def_bool y
  91. config RWSEM_GENERIC_SPINLOCK
  92. def_bool !X86_XADD
  93. config RWSEM_XCHGADD_ALGORITHM
  94. def_bool X86_XADD
  95. config ARCH_HAS_CPU_IDLE_WAIT
  96. def_bool y
  97. config GENERIC_CALIBRATE_DELAY
  98. def_bool y
  99. config GENERIC_TIME_VSYSCALL
  100. bool
  101. default X86_64
  102. config ARCH_HAS_CPU_RELAX
  103. def_bool y
  104. config ARCH_HAS_DEFAULT_IDLE
  105. def_bool y
  106. config ARCH_HAS_CACHE_LINE_SIZE
  107. def_bool y
  108. config HAVE_SETUP_PER_CPU_AREA
  109. def_bool y
  110. config HAVE_DYNAMIC_PER_CPU_AREA
  111. def_bool y
  112. config HAVE_CPUMASK_OF_CPU_MAP
  113. def_bool X86_64_SMP
  114. config ARCH_HIBERNATION_POSSIBLE
  115. def_bool y
  116. config ARCH_SUSPEND_POSSIBLE
  117. def_bool y
  118. config ZONE_DMA32
  119. bool
  120. default X86_64
  121. config ARCH_POPULATES_NODE_MAP
  122. def_bool y
  123. config AUDIT_ARCH
  124. bool
  125. default X86_64
  126. config ARCH_SUPPORTS_OPTIMIZED_INLINING
  127. def_bool y
  128. config ARCH_SUPPORTS_DEBUG_PAGEALLOC
  129. def_bool y
  130. # Use the generic interrupt handling code in kernel/irq/:
  131. config GENERIC_HARDIRQS
  132. bool
  133. default y
  134. config GENERIC_HARDIRQS_NO__DO_IRQ
  135. def_bool y
  136. config GENERIC_IRQ_PROBE
  137. bool
  138. default y
  139. config GENERIC_PENDING_IRQ
  140. bool
  141. depends on GENERIC_HARDIRQS && SMP
  142. default y
  143. config USE_GENERIC_SMP_HELPERS
  144. def_bool y
  145. depends on SMP
  146. config X86_32_SMP
  147. def_bool y
  148. depends on X86_32 && SMP
  149. config X86_64_SMP
  150. def_bool y
  151. depends on X86_64 && SMP
  152. config X86_HT
  153. bool
  154. depends on SMP
  155. default y
  156. config X86_TRAMPOLINE
  157. bool
  158. depends on SMP || (64BIT && ACPI_SLEEP)
  159. default y
  160. config X86_32_LAZY_GS
  161. def_bool y
  162. depends on X86_32 && !CC_STACKPROTECTOR
  163. config KTIME_SCALAR
  164. def_bool X86_32
  165. source "init/Kconfig"
  166. source "kernel/Kconfig.freezer"
  167. menu "Processor type and features"
  168. source "kernel/time/Kconfig"
  169. config SMP
  170. bool "Symmetric multi-processing support"
  171. ---help---
  172. This enables support for systems with more than one CPU. If you have
  173. a system with only one CPU, like most personal computers, say N. If
  174. you have a system with more than one CPU, say Y.
  175. If you say N here, the kernel will run on single and multiprocessor
  176. machines, but will use only one CPU of a multiprocessor machine. If
  177. you say Y here, the kernel will run on many, but not all,
  178. singleprocessor machines. On a singleprocessor machine, the kernel
  179. will run faster if you say N here.
  180. Note that if you say Y here and choose architecture "586" or
  181. "Pentium" under "Processor family", the kernel will not work on 486
  182. architectures. Similarly, multiprocessor kernels for the "PPro"
  183. architecture may not work on all Pentium based boards.
  184. People using multiprocessor machines who say Y here should also say
  185. Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
  186. Management" code will be disabled if you say Y here.
  187. See also <file:Documentation/i386/IO-APIC.txt>,
  188. <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
  189. <http://www.tldp.org/docs.html#howto>.
  190. If you don't know what to do here, say N.
  191. config X86_X2APIC
  192. bool "Support x2apic"
  193. depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
  194. ---help---
  195. This enables x2apic support on CPUs that have this feature.
  196. This allows 32-bit apic IDs (so it can support very large systems),
  197. and accesses the local apic via MSRs not via mmio.
  198. If you don't know what to do here, say N.
  199. config SPARSE_IRQ
  200. bool "Support sparse irq numbering"
  201. depends on PCI_MSI || HT_IRQ
  202. ---help---
  203. This enables support for sparse irqs. This is useful for distro
  204. kernels that want to define a high CONFIG_NR_CPUS value but still
  205. want to have low kernel memory footprint on smaller machines.
  206. ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
  207. out the irq_desc[] array in a more NUMA-friendly way. )
  208. If you don't know what to do here, say N.
  209. config NUMA_MIGRATE_IRQ_DESC
  210. bool "Move irq desc when changing irq smp_affinity"
  211. depends on SPARSE_IRQ && NUMA
  212. depends on BROKEN
  213. default n
  214. ---help---
  215. This enables moving irq_desc to cpu/node that irq will use handled.
  216. If you don't know what to do here, say N.
  217. config X86_MPPARSE
  218. bool "Enable MPS table" if ACPI
  219. default y
  220. depends on X86_LOCAL_APIC
  221. ---help---
  222. For old smp systems that do not have proper acpi support. Newer systems
  223. (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
  224. config X86_BIGSMP
  225. bool "Support for big SMP systems with more than 8 CPUs"
  226. depends on X86_32 && SMP
  227. ---help---
  228. This option is needed for the systems that have more than 8 CPUs
  229. if X86_32
  230. config X86_EXTENDED_PLATFORM
  231. bool "Support for extended (non-PC) x86 platforms"
  232. default y
  233. ---help---
  234. If you disable this option then the kernel will only support
  235. standard PC platforms. (which covers the vast majority of
  236. systems out there.)
  237. If you enable this option then you'll be able to select support
  238. for the following (non-PC) 32 bit x86 platforms:
  239. AMD Elan
  240. NUMAQ (IBM/Sequent)
  241. RDC R-321x SoC
  242. SGI 320/540 (Visual Workstation)
  243. Summit/EXA (IBM x440)
  244. Unisys ES7000 IA32 series
  245. If you have one of these systems, or if you want to build a
  246. generic distribution kernel, say Y here - otherwise say N.
  247. endif
  248. if X86_64
  249. config X86_EXTENDED_PLATFORM
  250. bool "Support for extended (non-PC) x86 platforms"
  251. default y
  252. ---help---
  253. If you disable this option then the kernel will only support
  254. standard PC platforms. (which covers the vast majority of
  255. systems out there.)
  256. If you enable this option then you'll be able to select support
  257. for the following (non-PC) 64 bit x86 platforms:
  258. ScaleMP vSMP
  259. SGI Ultraviolet
  260. If you have one of these systems, or if you want to build a
  261. generic distribution kernel, say Y here - otherwise say N.
  262. endif
  263. # This is an alphabetically sorted list of 64 bit extended platforms
  264. # Please maintain the alphabetic order if and when there are additions
  265. config X86_VSMP
  266. bool "ScaleMP vSMP"
  267. select PARAVIRT
  268. depends on X86_64 && PCI
  269. depends on X86_EXTENDED_PLATFORM
  270. ---help---
  271. Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
  272. supposed to run on these EM64T-based machines. Only choose this option
  273. if you have one of these machines.
  274. config X86_UV
  275. bool "SGI Ultraviolet"
  276. depends on X86_64
  277. depends on X86_EXTENDED_PLATFORM
  278. depends on NUMA
  279. select X86_X2APIC
  280. ---help---
  281. This option is needed in order to support SGI Ultraviolet systems.
  282. If you don't have one of these, you should say N here.
  283. # Following is an alphabetically sorted list of 32 bit extended platforms
  284. # Please maintain the alphabetic order if and when there are additions
  285. config X86_ELAN
  286. bool "AMD Elan"
  287. depends on X86_32
  288. depends on X86_EXTENDED_PLATFORM
  289. ---help---
  290. Select this for an AMD Elan processor.
  291. Do not use this option for K6/Athlon/Opteron processors!
  292. If unsure, choose "PC-compatible" instead.
  293. config X86_RDC321X
  294. bool "RDC R-321x SoC"
  295. depends on X86_32
  296. depends on X86_EXTENDED_PLATFORM
  297. select M486
  298. select X86_REBOOTFIXUPS
  299. ---help---
  300. This option is needed for RDC R-321x system-on-chip, also known
  301. as R-8610-(G).
  302. If you don't have one of these chips, you should say N here.
  303. config X86_32_NON_STANDARD
  304. bool "Support non-standard 32-bit SMP architectures"
  305. depends on X86_32 && SMP
  306. depends on X86_EXTENDED_PLATFORM
  307. ---help---
  308. This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
  309. subarchitectures. It is intended for a generic binary kernel.
  310. if you select them all, kernel will probe it one by one. and will
  311. fallback to default.
  312. # Alphabetically sorted list of Non standard 32 bit platforms
  313. config X86_NUMAQ
  314. bool "NUMAQ (IBM/Sequent)"
  315. depends on X86_32_NON_STANDARD
  316. select NUMA
  317. select X86_MPPARSE
  318. ---help---
  319. This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
  320. NUMA multiquad box. This changes the way that processors are
  321. bootstrapped, and uses Clustered Logical APIC addressing mode instead
  322. of Flat Logical. You will need a new lynxer.elf file to flash your
  323. firmware with - send email to <Martin.Bligh@us.ibm.com>.
  324. config X86_VISWS
  325. bool "SGI 320/540 (Visual Workstation)"
  326. depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
  327. depends on X86_32_NON_STANDARD
  328. ---help---
  329. The SGI Visual Workstation series is an IA32-based workstation
  330. based on SGI systems chips with some legacy PC hardware attached.
  331. Say Y here to create a kernel to run on the SGI 320 or 540.
  332. A kernel compiled for the Visual Workstation will run on general
  333. PCs as well. See <file:Documentation/sgi-visws.txt> for details.
  334. config X86_SUMMIT
  335. bool "Summit/EXA (IBM x440)"
  336. depends on X86_32_NON_STANDARD
  337. ---help---
  338. This option is needed for IBM systems that use the Summit/EXA chipset.
  339. In particular, it is needed for the x440.
  340. config X86_ES7000
  341. bool "Unisys ES7000 IA32 series"
  342. depends on X86_32_NON_STANDARD && X86_BIGSMP
  343. ---help---
  344. Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
  345. supposed to run on an IA32-based Unisys ES7000 system.
  346. config SCHED_OMIT_FRAME_POINTER
  347. def_bool y
  348. prompt "Single-depth WCHAN output"
  349. depends on X86
  350. ---help---
  351. Calculate simpler /proc/<PID>/wchan values. If this option
  352. is disabled then wchan values will recurse back to the
  353. caller function. This provides more accurate wchan values,
  354. at the expense of slightly more scheduling overhead.
  355. If in doubt, say "Y".
  356. menuconfig PARAVIRT_GUEST
  357. bool "Paravirtualized guest support"
  358. ---help---
  359. Say Y here to get to see options related to running Linux under
  360. various hypervisors. This option alone does not add any kernel code.
  361. If you say N, all options in this submenu will be skipped and disabled.
  362. if PARAVIRT_GUEST
  363. source "arch/x86/xen/Kconfig"
  364. config VMI
  365. bool "VMI Guest support"
  366. select PARAVIRT
  367. depends on X86_32
  368. ---help---
  369. VMI provides a paravirtualized interface to the VMware ESX server
  370. (it could be used by other hypervisors in theory too, but is not
  371. at the moment), by linking the kernel to a GPL-ed ROM module
  372. provided by the hypervisor.
  373. config KVM_CLOCK
  374. bool "KVM paravirtualized clock"
  375. select PARAVIRT
  376. select PARAVIRT_CLOCK
  377. ---help---
  378. Turning on this option will allow you to run a paravirtualized clock
  379. when running over the KVM hypervisor. Instead of relying on a PIT
  380. (or probably other) emulation by the underlying device model, the host
  381. provides the guest with timing infrastructure such as time of day, and
  382. system time
  383. config KVM_GUEST
  384. bool "KVM Guest support"
  385. select PARAVIRT
  386. ---help---
  387. This option enables various optimizations for running under the KVM
  388. hypervisor.
  389. source "arch/x86/lguest/Kconfig"
  390. config PARAVIRT
  391. bool "Enable paravirtualization code"
  392. ---help---
  393. This changes the kernel so it can modify itself when it is run
  394. under a hypervisor, potentially improving performance significantly
  395. over full virtualization. However, when run without a hypervisor
  396. the kernel is theoretically slower and slightly larger.
  397. config PARAVIRT_SPINLOCKS
  398. bool "Paravirtualization layer for spinlocks"
  399. depends on PARAVIRT && SMP && EXPERIMENTAL
  400. ---help---
  401. Paravirtualized spinlocks allow a pvops backend to replace the
  402. spinlock implementation with something virtualization-friendly
  403. (for example, block the virtual CPU rather than spinning).
  404. Unfortunately the downside is an up to 5% performance hit on
  405. native kernels, with various workloads.
  406. If you are unsure how to answer this question, answer N.
  407. config PARAVIRT_CLOCK
  408. bool
  409. default n
  410. endif
  411. config PARAVIRT_DEBUG
  412. bool "paravirt-ops debugging"
  413. depends on PARAVIRT && DEBUG_KERNEL
  414. ---help---
  415. Enable to debug paravirt_ops internals. Specifically, BUG if
  416. a paravirt_op is missing when it is called.
  417. config MEMTEST
  418. bool "Memtest"
  419. ---help---
  420. This option adds a kernel parameter 'memtest', which allows memtest
  421. to be set.
  422. memtest=0, mean disabled; -- default
  423. memtest=1, mean do 1 test pattern;
  424. ...
  425. memtest=4, mean do 4 test patterns.
  426. If you are unsure how to answer this question, answer N.
  427. config X86_SUMMIT_NUMA
  428. def_bool y
  429. depends on X86_32 && NUMA && X86_32_NON_STANDARD
  430. config X86_CYCLONE_TIMER
  431. def_bool y
  432. depends on X86_32_NON_STANDARD
  433. source "arch/x86/Kconfig.cpu"
  434. config HPET_TIMER
  435. def_bool X86_64
  436. prompt "HPET Timer Support" if X86_32
  437. ---help---
  438. Use the IA-PC HPET (High Precision Event Timer) to manage
  439. time in preference to the PIT and RTC, if a HPET is
  440. present.
  441. HPET is the next generation timer replacing legacy 8254s.
  442. The HPET provides a stable time base on SMP
  443. systems, unlike the TSC, but it is more expensive to access,
  444. as it is off-chip. You can find the HPET spec at
  445. <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
  446. You can safely choose Y here. However, HPET will only be
  447. activated if the platform and the BIOS support this feature.
  448. Otherwise the 8254 will be used for timing services.
  449. Choose N to continue using the legacy 8254 timer.
  450. config HPET_EMULATE_RTC
  451. def_bool y
  452. depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
  453. # Mark as embedded because too many people got it wrong.
  454. # The code disables itself when not needed.
  455. config DMI
  456. default y
  457. bool "Enable DMI scanning" if EMBEDDED
  458. ---help---
  459. Enabled scanning of DMI to identify machine quirks. Say Y
  460. here unless you have verified that your setup is not
  461. affected by entries in the DMI blacklist. Required by PNP
  462. BIOS code.
  463. config GART_IOMMU
  464. bool "GART IOMMU support" if EMBEDDED
  465. default y
  466. select SWIOTLB
  467. select AGP
  468. depends on X86_64 && PCI
  469. ---help---
  470. Support for full DMA access of devices with 32bit memory access only
  471. on systems with more than 3GB. This is usually needed for USB,
  472. sound, many IDE/SATA chipsets and some other devices.
  473. Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
  474. based hardware IOMMU and a software bounce buffer based IOMMU used
  475. on Intel systems and as fallback.
  476. The code is only active when needed (enough memory and limited
  477. device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
  478. too.
  479. config CALGARY_IOMMU
  480. bool "IBM Calgary IOMMU support"
  481. select SWIOTLB
  482. depends on X86_64 && PCI && EXPERIMENTAL
  483. ---help---
  484. Support for hardware IOMMUs in IBM's xSeries x366 and x460
  485. systems. Needed to run systems with more than 3GB of memory
  486. properly with 32-bit PCI devices that do not support DAC
  487. (Double Address Cycle). Calgary also supports bus level
  488. isolation, where all DMAs pass through the IOMMU. This
  489. prevents them from going anywhere except their intended
  490. destination. This catches hard-to-find kernel bugs and
  491. mis-behaving drivers and devices that do not use the DMA-API
  492. properly to set up their DMA buffers. The IOMMU can be
  493. turned off at boot time with the iommu=off parameter.
  494. Normally the kernel will make the right choice by itself.
  495. If unsure, say Y.
  496. config CALGARY_IOMMU_ENABLED_BY_DEFAULT
  497. def_bool y
  498. prompt "Should Calgary be enabled by default?"
  499. depends on CALGARY_IOMMU
  500. ---help---
  501. Should Calgary be enabled by default? if you choose 'y', Calgary
  502. will be used (if it exists). If you choose 'n', Calgary will not be
  503. used even if it exists. If you choose 'n' and would like to use
  504. Calgary anyway, pass 'iommu=calgary' on the kernel command line.
  505. If unsure, say Y.
  506. config AMD_IOMMU
  507. bool "AMD IOMMU support"
  508. select SWIOTLB
  509. select PCI_MSI
  510. depends on X86_64 && PCI && ACPI
  511. ---help---
  512. With this option you can enable support for AMD IOMMU hardware in
  513. your system. An IOMMU is a hardware component which provides
  514. remapping of DMA memory accesses from devices. With an AMD IOMMU you
  515. can isolate the the DMA memory of different devices and protect the
  516. system from misbehaving device drivers or hardware.
  517. You can find out if your system has an AMD IOMMU if you look into
  518. your BIOS for an option to enable it or if you have an IVRS ACPI
  519. table.
  520. config AMD_IOMMU_STATS
  521. bool "Export AMD IOMMU statistics to debugfs"
  522. depends on AMD_IOMMU
  523. select DEBUG_FS
  524. ---help---
  525. This option enables code in the AMD IOMMU driver to collect various
  526. statistics about whats happening in the driver and exports that
  527. information to userspace via debugfs.
  528. If unsure, say N.
  529. # need this always selected by IOMMU for the VIA workaround
  530. config SWIOTLB
  531. def_bool y if X86_64
  532. ---help---
  533. Support for software bounce buffers used on x86-64 systems
  534. which don't have a hardware IOMMU (e.g. the current generation
  535. of Intel's x86-64 CPUs). Using this PCI devices which can only
  536. access 32-bits of memory can be used on systems with more than
  537. 3 GB of memory. If unsure, say Y.
  538. config IOMMU_HELPER
  539. def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
  540. config IOMMU_API
  541. def_bool (AMD_IOMMU || DMAR)
  542. config MAXSMP
  543. bool "Configure Maximum number of SMP Processors and NUMA Nodes"
  544. depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
  545. select CPUMASK_OFFSTACK
  546. default n
  547. ---help---
  548. Configure maximum number of CPUS and NUMA Nodes for this architecture.
  549. If unsure, say N.
  550. config NR_CPUS
  551. int "Maximum number of CPUs" if SMP && !MAXSMP
  552. range 2 8 if SMP && X86_32 && !X86_BIGSMP
  553. range 2 512 if SMP && !MAXSMP
  554. default "1" if !SMP
  555. default "4096" if MAXSMP
  556. default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
  557. default "8" if SMP
  558. ---help---
  559. This allows you to specify the maximum number of CPUs which this
  560. kernel will support. The maximum supported value is 512 and the
  561. minimum value which makes sense is 2.
  562. This is purely to save memory - each supported CPU adds
  563. approximately eight kilobytes to the kernel image.
  564. config SCHED_SMT
  565. bool "SMT (Hyperthreading) scheduler support"
  566. depends on X86_HT
  567. ---help---
  568. SMT scheduler support improves the CPU scheduler's decision making
  569. when dealing with Intel Pentium 4 chips with HyperThreading at a
  570. cost of slightly increased overhead in some places. If unsure say
  571. N here.
  572. config SCHED_MC
  573. def_bool y
  574. prompt "Multi-core scheduler support"
  575. depends on X86_HT
  576. ---help---
  577. Multi-core scheduler support improves the CPU scheduler's decision
  578. making when dealing with multi-core CPU chips at a cost of slightly
  579. increased overhead in some places. If unsure say N here.
  580. source "kernel/Kconfig.preempt"
  581. config X86_UP_APIC
  582. bool "Local APIC support on uniprocessors"
  583. depends on X86_32 && !SMP && !X86_32_NON_STANDARD
  584. ---help---
  585. A local APIC (Advanced Programmable Interrupt Controller) is an
  586. integrated interrupt controller in the CPU. If you have a single-CPU
  587. system which has a processor with a local APIC, you can say Y here to
  588. enable and use it. If you say Y here even though your machine doesn't
  589. have a local APIC, then the kernel will still run with no slowdown at
  590. all. The local APIC supports CPU-generated self-interrupts (timer,
  591. performance counters), and the NMI watchdog which detects hard
  592. lockups.
  593. config X86_UP_IOAPIC
  594. bool "IO-APIC support on uniprocessors"
  595. depends on X86_UP_APIC
  596. ---help---
  597. An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
  598. SMP-capable replacement for PC-style interrupt controllers. Most
  599. SMP systems and many recent uniprocessor systems have one.
  600. If you have a single-CPU system with an IO-APIC, you can say Y here
  601. to use it. If you say Y here even though your machine doesn't have
  602. an IO-APIC, then the kernel will still run with no slowdown at all.
  603. config X86_LOCAL_APIC
  604. def_bool y
  605. depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
  606. config X86_IO_APIC
  607. def_bool y
  608. depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
  609. config X86_VISWS_APIC
  610. def_bool y
  611. depends on X86_32 && X86_VISWS
  612. config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
  613. bool "Reroute for broken boot IRQs"
  614. default n
  615. depends on X86_IO_APIC
  616. ---help---
  617. This option enables a workaround that fixes a source of
  618. spurious interrupts. This is recommended when threaded
  619. interrupt handling is used on systems where the generation of
  620. superfluous "boot interrupts" cannot be disabled.
  621. Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
  622. entry in the chipset's IO-APIC is masked (as, e.g. the RT
  623. kernel does during interrupt handling). On chipsets where this
  624. boot IRQ generation cannot be disabled, this workaround keeps
  625. the original IRQ line masked so that only the equivalent "boot
  626. IRQ" is delivered to the CPUs. The workaround also tells the
  627. kernel to set up the IRQ handler on the boot IRQ line. In this
  628. way only one interrupt is delivered to the kernel. Otherwise
  629. the spurious second interrupt may cause the kernel to bring
  630. down (vital) interrupt lines.
  631. Only affects "broken" chipsets. Interrupt sharing may be
  632. increased on these systems.
  633. config X86_MCE
  634. bool "Machine Check Exception"
  635. ---help---
  636. Machine Check Exception support allows the processor to notify the
  637. kernel if it detects a problem (e.g. overheating, component failure).
  638. The action the kernel takes depends on the severity of the problem,
  639. ranging from a warning message on the console, to halting the machine.
  640. Your processor must be a Pentium or newer to support this - check the
  641. flags in /proc/cpuinfo for mce. Note that some older Pentium systems
  642. have a design flaw which leads to false MCE events - hence MCE is
  643. disabled on all P5 processors, unless explicitly enabled with "mce"
  644. as a boot argument. Similarly, if MCE is built in and creates a
  645. problem on some new non-standard machine, you can boot with "nomce"
  646. to disable it. MCE support simply ignores non-MCE processors like
  647. the 386 and 486, so nearly everyone can say Y here.
  648. config X86_OLD_MCE
  649. depends on X86_32 && X86_MCE
  650. bool "Use legacy machine check code (will go away)"
  651. default n
  652. select X86_ANCIENT_MCE
  653. ---help---
  654. Use the old i386 machine check code. This is merely intended for
  655. testing in a transition period. Try this if you run into any machine
  656. check related software problems, but report the problem to
  657. linux-kernel. When in doubt say no.
  658. config X86_NEW_MCE
  659. depends on X86_MCE
  660. bool
  661. default y if (!X86_OLD_MCE && X86_32) || X86_64
  662. config X86_MCE_INTEL
  663. def_bool y
  664. prompt "Intel MCE features"
  665. depends on X86_NEW_MCE && X86_LOCAL_APIC
  666. ---help---
  667. Additional support for intel specific MCE features such as
  668. the thermal monitor.
  669. config X86_MCE_AMD
  670. def_bool y
  671. prompt "AMD MCE features"
  672. depends on X86_NEW_MCE && X86_LOCAL_APIC
  673. ---help---
  674. Additional support for AMD specific MCE features such as
  675. the DRAM Error Threshold.
  676. config X86_ANCIENT_MCE
  677. def_bool n
  678. depends on X86_32
  679. prompt "Support for old Pentium 5 / WinChip machine checks"
  680. ---help---
  681. Include support for machine check handling on old Pentium 5 or WinChip
  682. systems. These typically need to be enabled explicitely on the command
  683. line.
  684. config X86_MCE_THRESHOLD
  685. depends on X86_MCE_AMD || X86_MCE_INTEL
  686. bool
  687. default y
  688. config X86_MCE_INJECT
  689. depends on X86_NEW_MCE
  690. tristate "Machine check injector support"
  691. ---help---
  692. Provide support for injecting machine checks for testing purposes.
  693. If you don't know what a machine check is and you don't do kernel
  694. QA it is safe to say n.
  695. config X86_MCE_NONFATAL
  696. tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
  697. depends on X86_OLD_MCE
  698. ---help---
  699. Enabling this feature starts a timer that triggers every 5 seconds which
  700. will look at the machine check registers to see if anything happened.
  701. Non-fatal problems automatically get corrected (but still logged).
  702. Disable this if you don't want to see these messages.
  703. Seeing the messages this option prints out may be indicative of dying
  704. or out-of-spec (ie, overclocked) hardware.
  705. This option only does something on certain CPUs.
  706. (AMD Athlon/Duron and Intel Pentium 4)
  707. config X86_MCE_P4THERMAL
  708. bool "check for P4 thermal throttling interrupt."
  709. depends on X86_OLD_MCE && X86_MCE && (X86_UP_APIC || SMP)
  710. ---help---
  711. Enabling this feature will cause a message to be printed when the P4
  712. enters thermal throttling.
  713. config X86_THERMAL_VECTOR
  714. def_bool y
  715. depends on X86_MCE_P4THERMAL || X86_MCE_INTEL
  716. config VM86
  717. bool "Enable VM86 support" if EMBEDDED
  718. default y
  719. depends on X86_32
  720. ---help---
  721. This option is required by programs like DOSEMU to run 16-bit legacy
  722. code on X86 processors. It also may be needed by software like
  723. XFree86 to initialize some video cards via BIOS. Disabling this
  724. option saves about 6k.
  725. config TOSHIBA
  726. tristate "Toshiba Laptop support"
  727. depends on X86_32
  728. ---help---
  729. This adds a driver to safely access the System Management Mode of
  730. the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
  731. not work on models with a Phoenix BIOS. The System Management Mode
  732. is used to set the BIOS and power saving options on Toshiba portables.
  733. For information on utilities to make use of this driver see the
  734. Toshiba Linux utilities web site at:
  735. <http://www.buzzard.org.uk/toshiba/>.
  736. Say Y if you intend to run this kernel on a Toshiba portable.
  737. Say N otherwise.
  738. config I8K
  739. tristate "Dell laptop support"
  740. ---help---
  741. This adds a driver to safely access the System Management Mode
  742. of the CPU on the Dell Inspiron 8000. The System Management Mode
  743. is used to read cpu temperature and cooling fan status and to
  744. control the fans on the I8K portables.
  745. This driver has been tested only on the Inspiron 8000 but it may
  746. also work with other Dell laptops. You can force loading on other
  747. models by passing the parameter `force=1' to the module. Use at
  748. your own risk.
  749. For information on utilities to make use of this driver see the
  750. I8K Linux utilities web site at:
  751. <http://people.debian.org/~dz/i8k/>
  752. Say Y if you intend to run this kernel on a Dell Inspiron 8000.
  753. Say N otherwise.
  754. config X86_REBOOTFIXUPS
  755. bool "Enable X86 board specific fixups for reboot"
  756. depends on X86_32
  757. ---help---
  758. This enables chipset and/or board specific fixups to be done
  759. in order to get reboot to work correctly. This is only needed on
  760. some combinations of hardware and BIOS. The symptom, for which
  761. this config is intended, is when reboot ends with a stalled/hung
  762. system.
  763. Currently, the only fixup is for the Geode machines using
  764. CS5530A and CS5536 chipsets and the RDC R-321x SoC.
  765. Say Y if you want to enable the fixup. Currently, it's safe to
  766. enable this option even if you don't need it.
  767. Say N otherwise.
  768. config MICROCODE
  769. tristate "/dev/cpu/microcode - microcode support"
  770. select FW_LOADER
  771. ---help---
  772. If you say Y here, you will be able to update the microcode on
  773. certain Intel and AMD processors. The Intel support is for the
  774. IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
  775. Pentium 4, Xeon etc. The AMD support is for family 0x10 and
  776. 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
  777. You will obviously need the actual microcode binary data itself
  778. which is not shipped with the Linux kernel.
  779. This option selects the general module only, you need to select
  780. at least one vendor specific module as well.
  781. To compile this driver as a module, choose M here: the
  782. module will be called microcode.
  783. config MICROCODE_INTEL
  784. bool "Intel microcode patch loading support"
  785. depends on MICROCODE
  786. default MICROCODE
  787. select FW_LOADER
  788. ---help---
  789. This options enables microcode patch loading support for Intel
  790. processors.
  791. For latest news and information on obtaining all the required
  792. Intel ingredients for this driver, check:
  793. <http://www.urbanmyth.org/microcode/>.
  794. config MICROCODE_AMD
  795. bool "AMD microcode patch loading support"
  796. depends on MICROCODE
  797. select FW_LOADER
  798. ---help---
  799. If you select this option, microcode patch loading support for AMD
  800. processors will be enabled.
  801. config MICROCODE_OLD_INTERFACE
  802. def_bool y
  803. depends on MICROCODE
  804. config X86_MSR
  805. tristate "/dev/cpu/*/msr - Model-specific register support"
  806. ---help---
  807. This device gives privileged processes access to the x86
  808. Model-Specific Registers (MSRs). It is a character device with
  809. major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
  810. MSR accesses are directed to a specific CPU on multi-processor
  811. systems.
  812. config X86_CPUID
  813. tristate "/dev/cpu/*/cpuid - CPU information support"
  814. ---help---
  815. This device gives processes access to the x86 CPUID instruction to
  816. be executed on a specific processor. It is a character device
  817. with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
  818. /dev/cpu/31/cpuid.
  819. config X86_CPU_DEBUG
  820. tristate "/sys/kernel/debug/x86/cpu/* - CPU Debug support"
  821. ---help---
  822. If you select this option, this will provide various x86 CPUs
  823. information through debugfs.
  824. choice
  825. prompt "High Memory Support"
  826. default HIGHMEM4G if !X86_NUMAQ
  827. default HIGHMEM64G if X86_NUMAQ
  828. depends on X86_32
  829. config NOHIGHMEM
  830. bool "off"
  831. depends on !X86_NUMAQ
  832. ---help---
  833. Linux can use up to 64 Gigabytes of physical memory on x86 systems.
  834. However, the address space of 32-bit x86 processors is only 4
  835. Gigabytes large. That means that, if you have a large amount of
  836. physical memory, not all of it can be "permanently mapped" by the
  837. kernel. The physical memory that's not permanently mapped is called
  838. "high memory".
  839. If you are compiling a kernel which will never run on a machine with
  840. more than 1 Gigabyte total physical RAM, answer "off" here (default
  841. choice and suitable for most users). This will result in a "3GB/1GB"
  842. split: 3GB are mapped so that each process sees a 3GB virtual memory
  843. space and the remaining part of the 4GB virtual memory space is used
  844. by the kernel to permanently map as much physical memory as
  845. possible.
  846. If the machine has between 1 and 4 Gigabytes physical RAM, then
  847. answer "4GB" here.
  848. If more than 4 Gigabytes is used then answer "64GB" here. This
  849. selection turns Intel PAE (Physical Address Extension) mode on.
  850. PAE implements 3-level paging on IA32 processors. PAE is fully
  851. supported by Linux, PAE mode is implemented on all recent Intel
  852. processors (Pentium Pro and better). NOTE: If you say "64GB" here,
  853. then the kernel will not boot on CPUs that don't support PAE!
  854. The actual amount of total physical memory will either be
  855. auto detected or can be forced by using a kernel command line option
  856. such as "mem=256M". (Try "man bootparam" or see the documentation of
  857. your boot loader (lilo or loadlin) about how to pass options to the
  858. kernel at boot time.)
  859. If unsure, say "off".
  860. config HIGHMEM4G
  861. bool "4GB"
  862. depends on !X86_NUMAQ
  863. ---help---
  864. Select this if you have a 32-bit processor and between 1 and 4
  865. gigabytes of physical RAM.
  866. config HIGHMEM64G
  867. bool "64GB"
  868. depends on !M386 && !M486
  869. select X86_PAE
  870. ---help---
  871. Select this if you have a 32-bit processor and more than 4
  872. gigabytes of physical RAM.
  873. endchoice
  874. choice
  875. depends on EXPERIMENTAL
  876. prompt "Memory split" if EMBEDDED
  877. default VMSPLIT_3G
  878. depends on X86_32
  879. ---help---
  880. Select the desired split between kernel and user memory.
  881. If the address range available to the kernel is less than the
  882. physical memory installed, the remaining memory will be available
  883. as "high memory". Accessing high memory is a little more costly
  884. than low memory, as it needs to be mapped into the kernel first.
  885. Note that increasing the kernel address space limits the range
  886. available to user programs, making the address space there
  887. tighter. Selecting anything other than the default 3G/1G split
  888. will also likely make your kernel incompatible with binary-only
  889. kernel modules.
  890. If you are not absolutely sure what you are doing, leave this
  891. option alone!
  892. config VMSPLIT_3G
  893. bool "3G/1G user/kernel split"
  894. config VMSPLIT_3G_OPT
  895. depends on !X86_PAE
  896. bool "3G/1G user/kernel split (for full 1G low memory)"
  897. config VMSPLIT_2G
  898. bool "2G/2G user/kernel split"
  899. config VMSPLIT_2G_OPT
  900. depends on !X86_PAE
  901. bool "2G/2G user/kernel split (for full 2G low memory)"
  902. config VMSPLIT_1G
  903. bool "1G/3G user/kernel split"
  904. endchoice
  905. config PAGE_OFFSET
  906. hex
  907. default 0xB0000000 if VMSPLIT_3G_OPT
  908. default 0x80000000 if VMSPLIT_2G
  909. default 0x78000000 if VMSPLIT_2G_OPT
  910. default 0x40000000 if VMSPLIT_1G
  911. default 0xC0000000
  912. depends on X86_32
  913. config HIGHMEM
  914. def_bool y
  915. depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
  916. config X86_PAE
  917. bool "PAE (Physical Address Extension) Support"
  918. depends on X86_32 && !HIGHMEM4G
  919. ---help---
  920. PAE is required for NX support, and furthermore enables
  921. larger swapspace support for non-overcommit purposes. It
  922. has the cost of more pagetable lookup overhead, and also
  923. consumes more pagetable space per process.
  924. config ARCH_PHYS_ADDR_T_64BIT
  925. def_bool X86_64 || X86_PAE
  926. config DIRECT_GBPAGES
  927. bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
  928. default y
  929. depends on X86_64
  930. ---help---
  931. Allow the kernel linear mapping to use 1GB pages on CPUs that
  932. support it. This can improve the kernel's performance a tiny bit by
  933. reducing TLB pressure. If in doubt, say "Y".
  934. # Common NUMA Features
  935. config NUMA
  936. bool "Numa Memory Allocation and Scheduler Support"
  937. depends on SMP
  938. depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
  939. default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
  940. ---help---
  941. Enable NUMA (Non Uniform Memory Access) support.
  942. The kernel will try to allocate memory used by a CPU on the
  943. local memory controller of the CPU and add some more
  944. NUMA awareness to the kernel.
  945. For 64-bit this is recommended if the system is Intel Core i7
  946. (or later), AMD Opteron, or EM64T NUMA.
  947. For 32-bit this is only needed on (rare) 32-bit-only platforms
  948. that support NUMA topologies, such as NUMAQ / Summit, or if you
  949. boot a 32-bit kernel on a 64-bit NUMA platform.
  950. Otherwise, you should say N.
  951. comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
  952. depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
  953. config K8_NUMA
  954. def_bool y
  955. prompt "Old style AMD Opteron NUMA detection"
  956. depends on X86_64 && NUMA && PCI
  957. ---help---
  958. Enable K8 NUMA node topology detection. You should say Y here if
  959. you have a multi processor AMD K8 system. This uses an old
  960. method to read the NUMA configuration directly from the builtin
  961. Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
  962. instead, which also takes priority if both are compiled in.
  963. config X86_64_ACPI_NUMA
  964. def_bool y
  965. prompt "ACPI NUMA detection"
  966. depends on X86_64 && NUMA && ACPI && PCI
  967. select ACPI_NUMA
  968. ---help---
  969. Enable ACPI SRAT based node topology detection.
  970. # Some NUMA nodes have memory ranges that span
  971. # other nodes. Even though a pfn is valid and
  972. # between a node's start and end pfns, it may not
  973. # reside on that node. See memmap_init_zone()
  974. # for details.
  975. config NODES_SPAN_OTHER_NODES
  976. def_bool y
  977. depends on X86_64_ACPI_NUMA
  978. config NUMA_EMU
  979. bool "NUMA emulation"
  980. depends on X86_64 && NUMA
  981. ---help---
  982. Enable NUMA emulation. A flat machine will be split
  983. into virtual nodes when booted with "numa=fake=N", where N is the
  984. number of nodes. This is only useful for debugging.
  985. config NODES_SHIFT
  986. int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
  987. range 1 9
  988. default "9" if MAXSMP
  989. default "6" if X86_64
  990. default "4" if X86_NUMAQ
  991. default "3"
  992. depends on NEED_MULTIPLE_NODES
  993. ---help---
  994. Specify the maximum number of NUMA Nodes available on the target
  995. system. Increases memory reserved to accommodate various tables.
  996. config HAVE_ARCH_BOOTMEM
  997. def_bool y
  998. depends on X86_32 && NUMA
  999. config ARCH_HAVE_MEMORY_PRESENT
  1000. def_bool y
  1001. depends on X86_32 && DISCONTIGMEM
  1002. config NEED_NODE_MEMMAP_SIZE
  1003. def_bool y
  1004. depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
  1005. config HAVE_ARCH_ALLOC_REMAP
  1006. def_bool y
  1007. depends on X86_32 && NUMA
  1008. config ARCH_FLATMEM_ENABLE
  1009. def_bool y
  1010. depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
  1011. config ARCH_DISCONTIGMEM_ENABLE
  1012. def_bool y
  1013. depends on NUMA && X86_32
  1014. config ARCH_DISCONTIGMEM_DEFAULT
  1015. def_bool y
  1016. depends on NUMA && X86_32
  1017. config ARCH_SPARSEMEM_DEFAULT
  1018. def_bool y
  1019. depends on X86_64
  1020. config ARCH_SPARSEMEM_ENABLE
  1021. def_bool y
  1022. depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
  1023. select SPARSEMEM_STATIC if X86_32
  1024. select SPARSEMEM_VMEMMAP_ENABLE if X86_64
  1025. config ARCH_SELECT_MEMORY_MODEL
  1026. def_bool y
  1027. depends on ARCH_SPARSEMEM_ENABLE
  1028. config ARCH_MEMORY_PROBE
  1029. def_bool X86_64
  1030. depends on MEMORY_HOTPLUG
  1031. source "mm/Kconfig"
  1032. config HIGHPTE
  1033. bool "Allocate 3rd-level pagetables from highmem"
  1034. depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
  1035. ---help---
  1036. The VM uses one page table entry for each page of physical memory.
  1037. For systems with a lot of RAM, this can be wasteful of precious
  1038. low memory. Setting this option will put user-space page table
  1039. entries in high memory.
  1040. config X86_CHECK_BIOS_CORRUPTION
  1041. bool "Check for low memory corruption"
  1042. ---help---
  1043. Periodically check for memory corruption in low memory, which
  1044. is suspected to be caused by BIOS. Even when enabled in the
  1045. configuration, it is disabled at runtime. Enable it by
  1046. setting "memory_corruption_check=1" on the kernel command
  1047. line. By default it scans the low 64k of memory every 60
  1048. seconds; see the memory_corruption_check_size and
  1049. memory_corruption_check_period parameters in
  1050. Documentation/kernel-parameters.txt to adjust this.
  1051. When enabled with the default parameters, this option has
  1052. almost no overhead, as it reserves a relatively small amount
  1053. of memory and scans it infrequently. It both detects corruption
  1054. and prevents it from affecting the running system.
  1055. It is, however, intended as a diagnostic tool; if repeatable
  1056. BIOS-originated corruption always affects the same memory,
  1057. you can use memmap= to prevent the kernel from using that
  1058. memory.
  1059. config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
  1060. bool "Set the default setting of memory_corruption_check"
  1061. depends on X86_CHECK_BIOS_CORRUPTION
  1062. default y
  1063. ---help---
  1064. Set whether the default state of memory_corruption_check is
  1065. on or off.
  1066. config X86_RESERVE_LOW_64K
  1067. bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
  1068. default y
  1069. ---help---
  1070. Reserve the first 64K of physical RAM on BIOSes that are known
  1071. to potentially corrupt that memory range. A numbers of BIOSes are
  1072. known to utilize this area during suspend/resume, so it must not
  1073. be used by the kernel.
  1074. Set this to N if you are absolutely sure that you trust the BIOS
  1075. to get all its memory reservations and usages right.
  1076. If you have doubts about the BIOS (e.g. suspend/resume does not
  1077. work or there's kernel crashes after certain hardware hotplug
  1078. events) and it's not AMI or Phoenix, then you might want to enable
  1079. X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
  1080. corruption patterns.
  1081. Say Y if unsure.
  1082. config MATH_EMULATION
  1083. bool
  1084. prompt "Math emulation" if X86_32
  1085. ---help---
  1086. Linux can emulate a math coprocessor (used for floating point
  1087. operations) if you don't have one. 486DX and Pentium processors have
  1088. a math coprocessor built in, 486SX and 386 do not, unless you added
  1089. a 487DX or 387, respectively. (The messages during boot time can
  1090. give you some hints here ["man dmesg"].) Everyone needs either a
  1091. coprocessor or this emulation.
  1092. If you don't have a math coprocessor, you need to say Y here; if you
  1093. say Y here even though you have a coprocessor, the coprocessor will
  1094. be used nevertheless. (This behavior can be changed with the kernel
  1095. command line option "no387", which comes handy if your coprocessor
  1096. is broken. Try "man bootparam" or see the documentation of your boot
  1097. loader (lilo or loadlin) about how to pass options to the kernel at
  1098. boot time.) This means that it is a good idea to say Y here if you
  1099. intend to use this kernel on different machines.
  1100. More information about the internals of the Linux math coprocessor
  1101. emulation can be found in <file:arch/x86/math-emu/README>.
  1102. If you are not sure, say Y; apart from resulting in a 66 KB bigger
  1103. kernel, it won't hurt.
  1104. config MTRR
  1105. bool "MTRR (Memory Type Range Register) support"
  1106. ---help---
  1107. On Intel P6 family processors (Pentium Pro, Pentium II and later)
  1108. the Memory Type Range Registers (MTRRs) may be used to control
  1109. processor access to memory ranges. This is most useful if you have
  1110. a video (VGA) card on a PCI or AGP bus. Enabling write-combining
  1111. allows bus write transfers to be combined into a larger transfer
  1112. before bursting over the PCI/AGP bus. This can increase performance
  1113. of image write operations 2.5 times or more. Saying Y here creates a
  1114. /proc/mtrr file which may be used to manipulate your processor's
  1115. MTRRs. Typically the X server should use this.
  1116. This code has a reasonably generic interface so that similar
  1117. control registers on other processors can be easily supported
  1118. as well:
  1119. The Cyrix 6x86, 6x86MX and M II processors have Address Range
  1120. Registers (ARRs) which provide a similar functionality to MTRRs. For
  1121. these, the ARRs are used to emulate the MTRRs.
  1122. The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
  1123. MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
  1124. write-combining. All of these processors are supported by this code
  1125. and it makes sense to say Y here if you have one of them.
  1126. Saying Y here also fixes a problem with buggy SMP BIOSes which only
  1127. set the MTRRs for the boot CPU and not for the secondary CPUs. This
  1128. can lead to all sorts of problems, so it's good to say Y here.
  1129. You can safely say Y even if your machine doesn't have MTRRs, you'll
  1130. just add about 9 KB to your kernel.
  1131. See <file:Documentation/x86/mtrr.txt> for more information.
  1132. config MTRR_SANITIZER
  1133. def_bool y
  1134. prompt "MTRR cleanup support"
  1135. depends on MTRR
  1136. ---help---
  1137. Convert MTRR layout from continuous to discrete, so X drivers can
  1138. add writeback entries.
  1139. Can be disabled with disable_mtrr_cleanup on the kernel command line.
  1140. The largest mtrr entry size for a continuous block can be set with
  1141. mtrr_chunk_size.
  1142. If unsure, say Y.
  1143. config MTRR_SANITIZER_ENABLE_DEFAULT
  1144. int "MTRR cleanup enable value (0-1)"
  1145. range 0 1
  1146. default "0"
  1147. depends on MTRR_SANITIZER
  1148. ---help---
  1149. Enable mtrr cleanup default value
  1150. config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
  1151. int "MTRR cleanup spare reg num (0-7)"
  1152. range 0 7
  1153. default "1"
  1154. depends on MTRR_SANITIZER
  1155. ---help---
  1156. mtrr cleanup spare entries default, it can be changed via
  1157. mtrr_spare_reg_nr=N on the kernel command line.
  1158. config X86_PAT
  1159. bool
  1160. prompt "x86 PAT support"
  1161. depends on MTRR
  1162. ---help---
  1163. Use PAT attributes to setup page level cache control.
  1164. PATs are the modern equivalents of MTRRs and are much more
  1165. flexible than MTRRs.
  1166. Say N here if you see bootup problems (boot crash, boot hang,
  1167. spontaneous reboots) or a non-working video driver.
  1168. If unsure, say Y.
  1169. config EFI
  1170. bool "EFI runtime service support"
  1171. depends on ACPI
  1172. ---help---
  1173. This enables the kernel to use EFI runtime services that are
  1174. available (such as the EFI variable services).
  1175. This option is only useful on systems that have EFI firmware.
  1176. In addition, you should use the latest ELILO loader available
  1177. at <http://elilo.sourceforge.net> in order to take advantage
  1178. of EFI runtime services. However, even with this option, the
  1179. resultant kernel should continue to boot on existing non-EFI
  1180. platforms.
  1181. config SECCOMP
  1182. def_bool y
  1183. prompt "Enable seccomp to safely compute untrusted bytecode"
  1184. ---help---
  1185. This kernel feature is useful for number crunching applications
  1186. that may need to compute untrusted bytecode during their
  1187. execution. By using pipes or other transports made available to
  1188. the process as file descriptors supporting the read/write
  1189. syscalls, it's possible to isolate those applications in
  1190. their own address space using seccomp. Once seccomp is
  1191. enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
  1192. and the task is only allowed to execute a few safe syscalls
  1193. defined by each seccomp mode.
  1194. If unsure, say Y. Only embedded should say N here.
  1195. config CC_STACKPROTECTOR_ALL
  1196. bool
  1197. config CC_STACKPROTECTOR
  1198. bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
  1199. select CC_STACKPROTECTOR_ALL
  1200. ---help---
  1201. This option turns on the -fstack-protector GCC feature. This
  1202. feature puts, at the beginning of functions, a canary value on
  1203. the stack just before the return address, and validates
  1204. the value just before actually returning. Stack based buffer
  1205. overflows (that need to overwrite this return address) now also
  1206. overwrite the canary, which gets detected and the attack is then
  1207. neutralized via a kernel panic.
  1208. This feature requires gcc version 4.2 or above, or a distribution
  1209. gcc with the feature backported. Older versions are automatically
  1210. detected and for those versions, this configuration option is
  1211. ignored. (and a warning is printed during bootup)
  1212. source kernel/Kconfig.hz
  1213. config KEXEC
  1214. bool "kexec system call"
  1215. ---help---
  1216. kexec is a system call that implements the ability to shutdown your
  1217. current kernel, and to start another kernel. It is like a reboot
  1218. but it is independent of the system firmware. And like a reboot
  1219. you can start any kernel with it, not just Linux.
  1220. The name comes from the similarity to the exec system call.
  1221. It is an ongoing process to be certain the hardware in a machine
  1222. is properly shutdown, so do not be surprised if this code does not
  1223. initially work for you. It may help to enable device hotplugging
  1224. support. As of this writing the exact hardware interface is
  1225. strongly in flux, so no good recommendation can be made.
  1226. config CRASH_DUMP
  1227. bool "kernel crash dumps"
  1228. depends on X86_64 || (X86_32 && HIGHMEM)
  1229. ---help---
  1230. Generate crash dump after being started by kexec.
  1231. This should be normally only set in special crash dump kernels
  1232. which are loaded in the main kernel with kexec-tools into
  1233. a specially reserved region and then later executed after
  1234. a crash by kdump/kexec. The crash dump kernel must be compiled
  1235. to a memory address not used by the main kernel or BIOS using
  1236. PHYSICAL_START, or it must be built as a relocatable image
  1237. (CONFIG_RELOCATABLE=y).
  1238. For more details see Documentation/kdump/kdump.txt
  1239. config KEXEC_JUMP
  1240. bool "kexec jump (EXPERIMENTAL)"
  1241. depends on EXPERIMENTAL
  1242. depends on KEXEC && HIBERNATION
  1243. ---help---
  1244. Jump between original kernel and kexeced kernel and invoke
  1245. code in physical address mode via KEXEC
  1246. config PHYSICAL_START
  1247. hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
  1248. default "0x1000000" if X86_NUMAQ
  1249. default "0x200000" if X86_64
  1250. default "0x100000"
  1251. ---help---
  1252. This gives the physical address where the kernel is loaded.
  1253. If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
  1254. bzImage will decompress itself to above physical address and
  1255. run from there. Otherwise, bzImage will run from the address where
  1256. it has been loaded by the boot loader and will ignore above physical
  1257. address.
  1258. In normal kdump cases one does not have to set/change this option
  1259. as now bzImage can be compiled as a completely relocatable image
  1260. (CONFIG_RELOCATABLE=y) and be used to load and run from a different
  1261. address. This option is mainly useful for the folks who don't want
  1262. to use a bzImage for capturing the crash dump and want to use a
  1263. vmlinux instead. vmlinux is not relocatable hence a kernel needs
  1264. to be specifically compiled to run from a specific memory area
  1265. (normally a reserved region) and this option comes handy.
  1266. So if you are using bzImage for capturing the crash dump, leave
  1267. the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
  1268. Otherwise if you plan to use vmlinux for capturing the crash dump
  1269. change this value to start of the reserved region (Typically 16MB
  1270. 0x1000000). In other words, it can be set based on the "X" value as
  1271. specified in the "crashkernel=YM@XM" command line boot parameter
  1272. passed to the panic-ed kernel. Typically this parameter is set as
  1273. crashkernel=64M@16M. Please take a look at
  1274. Documentation/kdump/kdump.txt for more details about crash dumps.
  1275. Usage of bzImage for capturing the crash dump is recommended as
  1276. one does not have to build two kernels. Same kernel can be used
  1277. as production kernel and capture kernel. Above option should have
  1278. gone away after relocatable bzImage support is introduced. But it
  1279. is present because there are users out there who continue to use
  1280. vmlinux for dump capture. This option should go away down the
  1281. line.
  1282. Don't change this unless you know what you are doing.
  1283. config RELOCATABLE
  1284. bool "Build a relocatable kernel (EXPERIMENTAL)"
  1285. depends on EXPERIMENTAL
  1286. ---help---
  1287. This builds a kernel image that retains relocation information
  1288. so it can be loaded someplace besides the default 1MB.
  1289. The relocations tend to make the kernel binary about 10% larger,
  1290. but are discarded at runtime.
  1291. One use is for the kexec on panic case where the recovery kernel
  1292. must live at a different physical address than the primary
  1293. kernel.
  1294. Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
  1295. it has been loaded at and the compile time physical address
  1296. (CONFIG_PHYSICAL_START) is ignored.
  1297. config PHYSICAL_ALIGN
  1298. hex
  1299. prompt "Alignment value to which kernel should be aligned" if X86_32
  1300. default "0x100000" if X86_32
  1301. default "0x200000" if X86_64
  1302. range 0x2000 0x400000
  1303. ---help---
  1304. This value puts the alignment restrictions on physical address
  1305. where kernel is loaded and run from. Kernel is compiled for an
  1306. address which meets above alignment restriction.
  1307. If bootloader loads the kernel at a non-aligned address and
  1308. CONFIG_RELOCATABLE is set, kernel will move itself to nearest
  1309. address aligned to above value and run from there.
  1310. If bootloader loads the kernel at a non-aligned address and
  1311. CONFIG_RELOCATABLE is not set, kernel will ignore the run time
  1312. load address and decompress itself to the address it has been
  1313. compiled for and run from there. The address for which kernel is
  1314. compiled already meets above alignment restrictions. Hence the
  1315. end result is that kernel runs from a physical address meeting
  1316. above alignment restrictions.
  1317. Don't change this unless you know what you are doing.
  1318. config HOTPLUG_CPU
  1319. bool "Support for hot-pluggable CPUs"
  1320. depends on SMP && HOTPLUG
  1321. ---help---
  1322. Say Y here to allow turning CPUs off and on. CPUs can be
  1323. controlled through /sys/devices/system/cpu.
  1324. ( Note: power management support will enable this option
  1325. automatically on SMP systems. )
  1326. Say N if you want to disable CPU hotplug.
  1327. config COMPAT_VDSO
  1328. def_bool y
  1329. prompt "Compat VDSO support"
  1330. depends on X86_32 || IA32_EMULATION
  1331. ---help---
  1332. Map the 32-bit VDSO to the predictable old-style address too.
  1333. ---help---
  1334. Say N here if you are running a sufficiently recent glibc
  1335. version (2.3.3 or later), to remove the high-mapped
  1336. VDSO mapping and to exclusively use the randomized VDSO.
  1337. If unsure, say Y.
  1338. config CMDLINE_BOOL
  1339. bool "Built-in kernel command line"
  1340. default n
  1341. ---help---
  1342. Allow for specifying boot arguments to the kernel at
  1343. build time. On some systems (e.g. embedded ones), it is
  1344. necessary or convenient to provide some or all of the
  1345. kernel boot arguments with the kernel itself (that is,
  1346. to not rely on the boot loader to provide them.)
  1347. To compile command line arguments into the kernel,
  1348. set this option to 'Y', then fill in the
  1349. the boot arguments in CONFIG_CMDLINE.
  1350. Systems with fully functional boot loaders (i.e. non-embedded)
  1351. should leave this option set to 'N'.
  1352. config CMDLINE
  1353. string "Built-in kernel command string"
  1354. depends on CMDLINE_BOOL
  1355. default ""
  1356. ---help---
  1357. Enter arguments here that should be compiled into the kernel
  1358. image and used at boot time. If the boot loader provides a
  1359. command line at boot time, it is appended to this string to
  1360. form the full kernel command line, when the system boots.
  1361. However, you can use the CONFIG_CMDLINE_OVERRIDE option to
  1362. change this behavior.
  1363. In most cases, the command line (whether built-in or provided
  1364. by the boot loader) should specify the device for the root
  1365. file system.
  1366. config CMDLINE_OVERRIDE
  1367. bool "Built-in command line overrides boot loader arguments"
  1368. default n
  1369. depends on CMDLINE_BOOL
  1370. ---help---
  1371. Set this option to 'Y' to have the kernel ignore the boot loader
  1372. command line, and use ONLY the built-in command line.
  1373. This is used to work around broken boot loaders. This should
  1374. be set to 'N' under normal conditions.
  1375. endmenu
  1376. config ARCH_ENABLE_MEMORY_HOTPLUG
  1377. def_bool y
  1378. depends on X86_64 || (X86_32 && HIGHMEM)
  1379. config ARCH_ENABLE_MEMORY_HOTREMOVE
  1380. def_bool y
  1381. depends on MEMORY_HOTPLUG
  1382. config HAVE_ARCH_EARLY_PFN_TO_NID
  1383. def_bool X86_64
  1384. depends on NUMA
  1385. menu "Power management and ACPI options"
  1386. config ARCH_HIBERNATION_HEADER
  1387. def_bool y
  1388. depends on X86_64 && HIBERNATION
  1389. source "kernel/power/Kconfig"
  1390. source "drivers/acpi/Kconfig"
  1391. config X86_APM_BOOT
  1392. bool
  1393. default y
  1394. depends on APM || APM_MODULE
  1395. menuconfig APM
  1396. tristate "APM (Advanced Power Management) BIOS support"
  1397. depends on X86_32 && PM_SLEEP
  1398. ---help---
  1399. APM is a BIOS specification for saving power using several different
  1400. techniques. This is mostly useful for battery powered laptops with
  1401. APM compliant BIOSes. If you say Y here, the system time will be
  1402. reset after a RESUME operation, the /proc/apm device will provide
  1403. battery status information, and user-space programs will receive
  1404. notification of APM "events" (e.g. battery status change).
  1405. If you select "Y" here, you can disable actual use of the APM
  1406. BIOS by passing the "apm=off" option to the kernel at boot time.
  1407. Note that the APM support is almost completely disabled for
  1408. machines with more than one CPU.
  1409. In order to use APM, you will need supporting software. For location
  1410. and more information, read <file:Documentation/power/pm.txt> and the
  1411. Battery Powered Linux mini-HOWTO, available from
  1412. <http://www.tldp.org/docs.html#howto>.
  1413. This driver does not spin down disk drives (see the hdparm(8)
  1414. manpage ("man 8 hdparm") for that), and it doesn't turn off
  1415. VESA-compliant "green" monitors.
  1416. This driver does not support the TI 4000M TravelMate and the ACER
  1417. 486/DX4/75 because they don't have compliant BIOSes. Many "green"
  1418. desktop machines also don't have compliant BIOSes, and this driver
  1419. may cause those machines to panic during the boot phase.
  1420. Generally, if you don't have a battery in your machine, there isn't
  1421. much point in using this driver and you should say N. If you get
  1422. random kernel OOPSes or reboots that don't seem to be related to
  1423. anything, try disabling/enabling this option (or disabling/enabling
  1424. APM in your BIOS).
  1425. Some other things you should try when experiencing seemingly random,
  1426. "weird" problems:
  1427. 1) make sure that you have enough swap space and that it is
  1428. enabled.
  1429. 2) pass the "no-hlt" option to the kernel
  1430. 3) switch on floating point emulation in the kernel and pass
  1431. the "no387" option to the kernel
  1432. 4) pass the "floppy=nodma" option to the kernel
  1433. 5) pass the "mem=4M" option to the kernel (thereby disabling
  1434. all but the first 4 MB of RAM)
  1435. 6) make sure that the CPU is not over clocked.
  1436. 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
  1437. 8) disable the cache from your BIOS settings
  1438. 9) install a fan for the video card or exchange video RAM
  1439. 10) install a better fan for the CPU
  1440. 11) exchange RAM chips
  1441. 12) exchange the motherboard.
  1442. To compile this driver as a module, choose M here: the
  1443. module will be called apm.
  1444. if APM
  1445. config APM_IGNORE_USER_SUSPEND
  1446. bool "Ignore USER SUSPEND"
  1447. ---help---
  1448. This option will ignore USER SUSPEND requests. On machines with a
  1449. compliant APM BIOS, you want to say N. However, on the NEC Versa M
  1450. series notebooks, it is necessary to say Y because of a BIOS bug.
  1451. config APM_DO_ENABLE
  1452. bool "Enable PM at boot time"
  1453. ---help---
  1454. Enable APM features at boot time. From page 36 of the APM BIOS
  1455. specification: "When disabled, the APM BIOS does not automatically
  1456. power manage devices, enter the Standby State, enter the Suspend
  1457. State, or take power saving steps in response to CPU Idle calls."
  1458. This driver will make CPU Idle calls when Linux is idle (unless this
  1459. feature is turned off -- see "Do CPU IDLE calls", below). This
  1460. should always save battery power, but more complicated APM features
  1461. will be dependent on your BIOS implementation. You may need to turn
  1462. this option off if your computer hangs at boot time when using APM
  1463. support, or if it beeps continuously instead of suspending. Turn
  1464. this off if you have a NEC UltraLite Versa 33/C or a Toshiba
  1465. T400CDT. This is off by default since most machines do fine without
  1466. this feature.
  1467. config APM_CPU_IDLE
  1468. bool "Make CPU Idle calls when idle"
  1469. ---help---
  1470. Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
  1471. On some machines, this can activate improved power savings, such as
  1472. a slowed CPU clock rate, when the machine is idle. These idle calls
  1473. are made after the idle loop has run for some length of time (e.g.,
  1474. 333 mS). On some machines, this will cause a hang at boot time or
  1475. whenever the CPU becomes idle. (On machines with more than one CPU,
  1476. this option does nothing.)
  1477. config APM_DISPLAY_BLANK
  1478. bool "Enable console blanking using APM"
  1479. ---help---
  1480. Enable console blanking using the APM. Some laptops can use this to
  1481. turn off the LCD backlight when the screen blanker of the Linux
  1482. virtual console blanks the screen. Note that this is only used by
  1483. the virtual console screen blanker, and won't turn off the backlight
  1484. when using the X Window system. This also doesn't have anything to
  1485. do with your VESA-compliant power-saving monitor. Further, this
  1486. option doesn't work for all laptops -- it might not turn off your
  1487. backlight at all, or it might print a lot of errors to the console,
  1488. especially if you are using gpm.
  1489. config APM_ALLOW_INTS
  1490. bool "Allow interrupts during APM BIOS calls"
  1491. ---help---
  1492. Normally we disable external interrupts while we are making calls to
  1493. the APM BIOS as a measure to lessen the effects of a badly behaving
  1494. BIOS implementation. The BIOS should reenable interrupts if it
  1495. needs to. Unfortunately, some BIOSes do not -- especially those in
  1496. many of the newer IBM Thinkpads. If you experience hangs when you
  1497. suspend, try setting this to Y. Otherwise, say N.
  1498. endif # APM
  1499. source "arch/x86/kernel/cpu/cpufreq/Kconfig"
  1500. source "drivers/cpuidle/Kconfig"
  1501. source "drivers/idle/Kconfig"
  1502. endmenu
  1503. menu "Bus options (PCI etc.)"
  1504. config PCI
  1505. bool "PCI support"
  1506. default y
  1507. select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
  1508. ---help---
  1509. Find out whether you have a PCI motherboard. PCI is the name of a
  1510. bus system, i.e. the way the CPU talks to the other stuff inside
  1511. your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
  1512. VESA. If you have PCI, say Y, otherwise N.
  1513. choice
  1514. prompt "PCI access mode"
  1515. depends on X86_32 && PCI
  1516. default PCI_GOANY
  1517. ---help---
  1518. On PCI systems, the BIOS can be used to detect the PCI devices and
  1519. determine their configuration. However, some old PCI motherboards
  1520. have BIOS bugs and may crash if this is done. Also, some embedded
  1521. PCI-based systems don't have any BIOS at all. Linux can also try to
  1522. detect the PCI hardware directly without using the BIOS.
  1523. With this option, you can specify how Linux should detect the
  1524. PCI devices. If you choose "BIOS", the BIOS will be used,
  1525. if you choose "Direct", the BIOS won't be used, and if you
  1526. choose "MMConfig", then PCI Express MMCONFIG will be used.
  1527. If you choose "Any", the kernel will try MMCONFIG, then the
  1528. direct access method and falls back to the BIOS if that doesn't
  1529. work. If unsure, go with the default, which is "Any".
  1530. config PCI_GOBIOS
  1531. bool "BIOS"
  1532. config PCI_GOMMCONFIG
  1533. bool "MMConfig"
  1534. config PCI_GODIRECT
  1535. bool "Direct"
  1536. config PCI_GOOLPC
  1537. bool "OLPC"
  1538. depends on OLPC
  1539. config PCI_GOANY
  1540. bool "Any"
  1541. endchoice
  1542. config PCI_BIOS
  1543. def_bool y
  1544. depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
  1545. # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
  1546. config PCI_DIRECT
  1547. def_bool y
  1548. depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
  1549. config PCI_MMCONFIG
  1550. def_bool y
  1551. depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
  1552. config PCI_OLPC
  1553. def_bool y
  1554. depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
  1555. config PCI_DOMAINS
  1556. def_bool y
  1557. depends on PCI
  1558. config PCI_MMCONFIG
  1559. bool "Support mmconfig PCI config space access"
  1560. depends on X86_64 && PCI && ACPI
  1561. config DMAR
  1562. bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
  1563. depends on PCI_MSI && ACPI && EXPERIMENTAL
  1564. help
  1565. DMA remapping (DMAR) devices support enables independent address
  1566. translations for Direct Memory Access (DMA) from devices.
  1567. These DMA remapping devices are reported via ACPI tables
  1568. and include PCI device scope covered by these DMA
  1569. remapping devices.
  1570. config DMAR_DEFAULT_ON
  1571. def_bool y
  1572. prompt "Enable DMA Remapping Devices by default"
  1573. depends on DMAR
  1574. help
  1575. Selecting this option will enable a DMAR device at boot time if
  1576. one is found. If this option is not selected, DMAR support can
  1577. be enabled by passing intel_iommu=on to the kernel. It is
  1578. recommended you say N here while the DMAR code remains
  1579. experimental.
  1580. config DMAR_GFX_WA
  1581. def_bool y
  1582. prompt "Support for Graphics workaround"
  1583. depends on DMAR
  1584. ---help---
  1585. Current Graphics drivers tend to use physical address
  1586. for DMA and avoid using DMA APIs. Setting this config
  1587. option permits the IOMMU driver to set a unity map for
  1588. all the OS-visible memory. Hence the driver can continue
  1589. to use physical addresses for DMA.
  1590. config DMAR_FLOPPY_WA
  1591. def_bool y
  1592. depends on DMAR
  1593. ---help---
  1594. Floppy disk drivers are know to bypass DMA API calls
  1595. thereby failing to work when IOMMU is enabled. This
  1596. workaround will setup a 1:1 mapping for the first
  1597. 16M to make floppy (an ISA device) work.
  1598. config INTR_REMAP
  1599. bool "Support for Interrupt Remapping (EXPERIMENTAL)"
  1600. depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
  1601. ---help---
  1602. Supports Interrupt remapping for IO-APIC and MSI devices.
  1603. To use x2apic mode in the CPU's which support x2APIC enhancements or
  1604. to support platforms with CPU's having > 8 bit APIC ID, say Y.
  1605. source "drivers/pci/pcie/Kconfig"
  1606. source "drivers/pci/Kconfig"
  1607. # x86_64 have no ISA slots, but do have ISA-style DMA.
  1608. config ISA_DMA_API
  1609. def_bool y
  1610. if X86_32
  1611. config ISA
  1612. bool "ISA support"
  1613. ---help---
  1614. Find out whether you have ISA slots on your motherboard. ISA is the
  1615. name of a bus system, i.e. the way the CPU talks to the other stuff
  1616. inside your box. Other bus systems are PCI, EISA, MicroChannel
  1617. (MCA) or VESA. ISA is an older system, now being displaced by PCI;
  1618. newer boards don't support it. If you have ISA, say Y, otherwise N.
  1619. config EISA
  1620. bool "EISA support"
  1621. depends on ISA
  1622. ---help---
  1623. The Extended Industry Standard Architecture (EISA) bus was
  1624. developed as an open alternative to the IBM MicroChannel bus.
  1625. The EISA bus provided some of the features of the IBM MicroChannel
  1626. bus while maintaining backward compatibility with cards made for
  1627. the older ISA bus. The EISA bus saw limited use between 1988 and
  1628. 1995 when it was made obsolete by the PCI bus.
  1629. Say Y here if you are building a kernel for an EISA-based machine.
  1630. Otherwise, say N.
  1631. source "drivers/eisa/Kconfig"
  1632. config MCA
  1633. bool "MCA support"
  1634. ---help---
  1635. MicroChannel Architecture is found in some IBM PS/2 machines and
  1636. laptops. It is a bus system similar to PCI or ISA. See
  1637. <file:Documentation/mca.txt> (and especially the web page given
  1638. there) before attempting to build an MCA bus kernel.
  1639. source "drivers/mca/Kconfig"
  1640. config SCx200
  1641. tristate "NatSemi SCx200 support"
  1642. ---help---
  1643. This provides basic support for National Semiconductor's
  1644. (now AMD's) Geode processors. The driver probes for the
  1645. PCI-IDs of several on-chip devices, so its a good dependency
  1646. for other scx200_* drivers.
  1647. If compiled as a module, the driver is named scx200.
  1648. config SCx200HR_TIMER
  1649. tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
  1650. depends on SCx200 && GENERIC_TIME
  1651. default y
  1652. ---help---
  1653. This driver provides a clocksource built upon the on-chip
  1654. 27MHz high-resolution timer. Its also a workaround for
  1655. NSC Geode SC-1100's buggy TSC, which loses time when the
  1656. processor goes idle (as is done by the scheduler). The
  1657. other workaround is idle=poll boot option.
  1658. config GEODE_MFGPT_TIMER
  1659. def_bool y
  1660. prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
  1661. depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
  1662. ---help---
  1663. This driver provides a clock event source based on the MFGPT
  1664. timer(s) in the CS5535 and CS5536 companion chip for the geode.
  1665. MFGPTs have a better resolution and max interval than the
  1666. generic PIT, and are suitable for use as high-res timers.
  1667. config OLPC
  1668. bool "One Laptop Per Child support"
  1669. default n
  1670. ---help---
  1671. Add support for detecting the unique features of the OLPC
  1672. XO hardware.
  1673. endif # X86_32
  1674. config K8_NB
  1675. def_bool y
  1676. depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
  1677. source "drivers/pcmcia/Kconfig"
  1678. source "drivers/pci/hotplug/Kconfig"
  1679. endmenu
  1680. menu "Executable file formats / Emulations"
  1681. source "fs/Kconfig.binfmt"
  1682. config IA32_EMULATION
  1683. bool "IA32 Emulation"
  1684. depends on X86_64
  1685. select COMPAT_BINFMT_ELF
  1686. ---help---
  1687. Include code to run 32-bit programs under a 64-bit kernel. You should
  1688. likely turn this on, unless you're 100% sure that you don't have any
  1689. 32-bit programs left.
  1690. config IA32_AOUT
  1691. tristate "IA32 a.out support"
  1692. depends on IA32_EMULATION
  1693. ---help---
  1694. Support old a.out binaries in the 32bit emulation.
  1695. config COMPAT
  1696. def_bool y
  1697. depends on IA32_EMULATION
  1698. config COMPAT_FOR_U64_ALIGNMENT
  1699. def_bool COMPAT
  1700. depends on X86_64
  1701. config SYSVIPC_COMPAT
  1702. def_bool y
  1703. depends on COMPAT && SYSVIPC
  1704. endmenu
  1705. config HAVE_ATOMIC_IOMAP
  1706. def_bool y
  1707. depends on X86_32
  1708. source "net/Kconfig"
  1709. source "drivers/Kconfig"
  1710. source "drivers/firmware/Kconfig"
  1711. source "fs/Kconfig"
  1712. source "arch/x86/Kconfig.debug"
  1713. source "security/Kconfig"
  1714. source "crypto/Kconfig"
  1715. source "arch/x86/kvm/Kconfig"
  1716. source "lib/Kconfig"