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