Kconfig 66 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_PERF_EVENTS if (!M386 && !M486)
  24. select HAVE_IOREMAP_PROT
  25. select HAVE_KPROBES
  26. select ARCH_WANT_OPTIONAL_GPIOLIB
  27. select ARCH_WANT_FRAME_POINTERS
  28. select HAVE_DMA_ATTRS
  29. select HAVE_KRETPROBES
  30. select HAVE_FTRACE_MCOUNT_RECORD
  31. select HAVE_DYNAMIC_FTRACE
  32. select HAVE_FUNCTION_TRACER
  33. select HAVE_FUNCTION_GRAPH_TRACER
  34. select HAVE_FUNCTION_GRAPH_FP_TEST
  35. select HAVE_FUNCTION_TRACE_MCOUNT_TEST
  36. select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
  37. select HAVE_SYSCALL_TRACEPOINTS
  38. select HAVE_KVM
  39. select HAVE_ARCH_KGDB
  40. select HAVE_ARCH_TRACEHOOK
  41. select HAVE_GENERIC_DMA_COHERENT if X86_32
  42. select HAVE_EFFICIENT_UNALIGNED_ACCESS
  43. select USER_STACKTRACE_SUPPORT
  44. select HAVE_DMA_API_DEBUG
  45. select HAVE_KERNEL_GZIP
  46. select HAVE_KERNEL_BZIP2
  47. select HAVE_KERNEL_LZMA
  48. select HAVE_ARCH_KMEMCHECK
  49. select HAVE_USER_RETURN_NOTIFIER
  50. config OUTPUT_FORMAT
  51. string
  52. default "elf32-i386" if X86_32
  53. default "elf64-x86-64" if X86_64
  54. config ARCH_DEFCONFIG
  55. string
  56. default "arch/x86/configs/i386_defconfig" if X86_32
  57. default "arch/x86/configs/x86_64_defconfig" if X86_64
  58. config GENERIC_TIME
  59. def_bool y
  60. config GENERIC_CMOS_UPDATE
  61. def_bool y
  62. config CLOCKSOURCE_WATCHDOG
  63. def_bool y
  64. config GENERIC_CLOCKEVENTS
  65. def_bool y
  66. config GENERIC_CLOCKEVENTS_BROADCAST
  67. def_bool y
  68. depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
  69. config LOCKDEP_SUPPORT
  70. def_bool y
  71. config STACKTRACE_SUPPORT
  72. def_bool y
  73. config HAVE_LATENCYTOP_SUPPORT
  74. def_bool y
  75. config FAST_CMPXCHG_LOCAL
  76. bool
  77. default y
  78. config MMU
  79. def_bool y
  80. config ZONE_DMA
  81. def_bool y
  82. config SBUS
  83. bool
  84. config GENERIC_ISA_DMA
  85. def_bool y
  86. config GENERIC_IOMAP
  87. def_bool y
  88. config GENERIC_BUG
  89. def_bool y
  90. depends on BUG
  91. select GENERIC_BUG_RELATIVE_POINTERS if X86_64
  92. config GENERIC_BUG_RELATIVE_POINTERS
  93. bool
  94. config GENERIC_HWEIGHT
  95. def_bool y
  96. config GENERIC_GPIO
  97. bool
  98. config ARCH_MAY_HAVE_PC_FDC
  99. def_bool y
  100. config RWSEM_GENERIC_SPINLOCK
  101. def_bool !X86_XADD
  102. config RWSEM_XCHGADD_ALGORITHM
  103. def_bool X86_XADD
  104. config ARCH_HAS_CPU_IDLE_WAIT
  105. def_bool y
  106. config GENERIC_CALIBRATE_DELAY
  107. def_bool y
  108. config GENERIC_TIME_VSYSCALL
  109. bool
  110. default X86_64
  111. config ARCH_HAS_CPU_RELAX
  112. def_bool y
  113. config ARCH_HAS_DEFAULT_IDLE
  114. def_bool y
  115. config ARCH_HAS_CACHE_LINE_SIZE
  116. def_bool y
  117. config HAVE_SETUP_PER_CPU_AREA
  118. def_bool y
  119. config NEED_PER_CPU_EMBED_FIRST_CHUNK
  120. def_bool y
  121. config NEED_PER_CPU_PAGE_FIRST_CHUNK
  122. def_bool y
  123. config HAVE_CPUMASK_OF_CPU_MAP
  124. def_bool X86_64_SMP
  125. config ARCH_HIBERNATION_POSSIBLE
  126. def_bool y
  127. config ARCH_SUSPEND_POSSIBLE
  128. def_bool y
  129. config ZONE_DMA32
  130. bool
  131. default X86_64
  132. config ARCH_POPULATES_NODE_MAP
  133. def_bool y
  134. config AUDIT_ARCH
  135. bool
  136. default X86_64
  137. config ARCH_SUPPORTS_OPTIMIZED_INLINING
  138. def_bool y
  139. config ARCH_SUPPORTS_DEBUG_PAGEALLOC
  140. def_bool y
  141. config HAVE_INTEL_TXT
  142. def_bool y
  143. depends on EXPERIMENTAL && DMAR && ACPI
  144. # Use the generic interrupt handling code in kernel/irq/:
  145. config GENERIC_HARDIRQS
  146. bool
  147. default y
  148. config GENERIC_HARDIRQS_NO__DO_IRQ
  149. def_bool y
  150. config GENERIC_IRQ_PROBE
  151. bool
  152. default y
  153. config GENERIC_PENDING_IRQ
  154. bool
  155. depends on GENERIC_HARDIRQS && SMP
  156. default y
  157. config USE_GENERIC_SMP_HELPERS
  158. def_bool y
  159. depends on SMP
  160. config X86_32_SMP
  161. def_bool y
  162. depends on X86_32 && SMP
  163. config X86_64_SMP
  164. def_bool y
  165. depends on X86_64 && SMP
  166. config X86_HT
  167. bool
  168. depends on SMP
  169. default y
  170. config X86_TRAMPOLINE
  171. bool
  172. depends on SMP || (64BIT && ACPI_SLEEP)
  173. default y
  174. config X86_32_LAZY_GS
  175. def_bool y
  176. depends on X86_32 && !CC_STACKPROTECTOR
  177. config KTIME_SCALAR
  178. def_bool X86_32
  179. source "init/Kconfig"
  180. source "kernel/Kconfig.freezer"
  181. menu "Processor type and features"
  182. source "kernel/time/Kconfig"
  183. config SMP
  184. bool "Symmetric multi-processing support"
  185. ---help---
  186. This enables support for systems with more than one CPU. If you have
  187. a system with only one CPU, like most personal computers, say N. If
  188. you have a system with more than one CPU, say Y.
  189. If you say N here, the kernel will run on single and multiprocessor
  190. machines, but will use only one CPU of a multiprocessor machine. If
  191. you say Y here, the kernel will run on many, but not all,
  192. singleprocessor machines. On a singleprocessor machine, the kernel
  193. will run faster if you say N here.
  194. Note that if you say Y here and choose architecture "586" or
  195. "Pentium" under "Processor family", the kernel will not work on 486
  196. architectures. Similarly, multiprocessor kernels for the "PPro"
  197. architecture may not work on all Pentium based boards.
  198. People using multiprocessor machines who say Y here should also say
  199. Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
  200. Management" code will be disabled if you say Y here.
  201. See also <file:Documentation/i386/IO-APIC.txt>,
  202. <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
  203. <http://www.tldp.org/docs.html#howto>.
  204. If you don't know what to do here, say N.
  205. config X86_X2APIC
  206. bool "Support x2apic"
  207. depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
  208. ---help---
  209. This enables x2apic support on CPUs that have this feature.
  210. This allows 32-bit apic IDs (so it can support very large systems),
  211. and accesses the local apic via MSRs not via mmio.
  212. If you don't know what to do here, say N.
  213. config SPARSE_IRQ
  214. bool "Support sparse irq numbering"
  215. depends on PCI_MSI || HT_IRQ
  216. ---help---
  217. This enables support for sparse irqs. This is useful for distro
  218. kernels that want to define a high CONFIG_NR_CPUS value but still
  219. want to have low kernel memory footprint on smaller machines.
  220. ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
  221. out the irq_desc[] array in a more NUMA-friendly way. )
  222. If you don't know what to do here, say N.
  223. config NUMA_IRQ_DESC
  224. def_bool y
  225. depends on SPARSE_IRQ && NUMA
  226. config X86_MPPARSE
  227. bool "Enable MPS table" if ACPI
  228. default y
  229. depends on X86_LOCAL_APIC
  230. ---help---
  231. For old smp systems that do not have proper acpi support. Newer systems
  232. (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
  233. config X86_BIGSMP
  234. bool "Support for big SMP systems with more than 8 CPUs"
  235. depends on X86_32 && SMP
  236. ---help---
  237. This option is needed for the systems that have more than 8 CPUs
  238. if X86_32
  239. config X86_EXTENDED_PLATFORM
  240. bool "Support for extended (non-PC) x86 platforms"
  241. default y
  242. ---help---
  243. If you disable this option then the kernel will only support
  244. standard PC platforms. (which covers the vast majority of
  245. systems out there.)
  246. If you enable this option then you'll be able to select support
  247. for the following (non-PC) 32 bit x86 platforms:
  248. AMD Elan
  249. NUMAQ (IBM/Sequent)
  250. RDC R-321x SoC
  251. SGI 320/540 (Visual Workstation)
  252. Summit/EXA (IBM x440)
  253. Unisys ES7000 IA32 series
  254. Moorestown MID devices
  255. If you have one of these systems, or if you want to build a
  256. generic distribution kernel, say Y here - otherwise say N.
  257. endif
  258. if X86_64
  259. config X86_EXTENDED_PLATFORM
  260. bool "Support for extended (non-PC) x86 platforms"
  261. default y
  262. ---help---
  263. If you disable this option then the kernel will only support
  264. standard PC platforms. (which covers the vast majority of
  265. systems out there.)
  266. If you enable this option then you'll be able to select support
  267. for the following (non-PC) 64 bit x86 platforms:
  268. ScaleMP vSMP
  269. SGI Ultraviolet
  270. If you have one of these systems, or if you want to build a
  271. generic distribution kernel, say Y here - otherwise say N.
  272. endif
  273. # This is an alphabetically sorted list of 64 bit extended platforms
  274. # Please maintain the alphabetic order if and when there are additions
  275. config X86_VSMP
  276. bool "ScaleMP vSMP"
  277. select PARAVIRT
  278. depends on X86_64 && PCI
  279. depends on X86_EXTENDED_PLATFORM
  280. ---help---
  281. Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
  282. supposed to run on these EM64T-based machines. Only choose this option
  283. if you have one of these machines.
  284. config X86_UV
  285. bool "SGI Ultraviolet"
  286. depends on X86_64
  287. depends on X86_EXTENDED_PLATFORM
  288. depends on NUMA
  289. depends on X86_X2APIC
  290. ---help---
  291. This option is needed in order to support SGI Ultraviolet systems.
  292. If you don't have one of these, you should say N here.
  293. # Following is an alphabetically sorted list of 32 bit extended platforms
  294. # Please maintain the alphabetic order if and when there are additions
  295. config X86_ELAN
  296. bool "AMD Elan"
  297. depends on X86_32
  298. depends on X86_EXTENDED_PLATFORM
  299. ---help---
  300. Select this for an AMD Elan processor.
  301. Do not use this option for K6/Athlon/Opteron processors!
  302. If unsure, choose "PC-compatible" instead.
  303. config X86_MRST
  304. bool "Moorestown MID platform"
  305. depends on X86_32
  306. depends on X86_EXTENDED_PLATFORM
  307. ---help---
  308. Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
  309. Internet Device(MID) platform. Moorestown consists of two chips:
  310. Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
  311. Unlike standard x86 PCs, Moorestown does not have many legacy devices
  312. nor standard legacy replacement devices/features. e.g. Moorestown does
  313. not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
  314. config X86_RDC321X
  315. bool "RDC R-321x SoC"
  316. depends on X86_32
  317. depends on X86_EXTENDED_PLATFORM
  318. select M486
  319. select X86_REBOOTFIXUPS
  320. ---help---
  321. This option is needed for RDC R-321x system-on-chip, also known
  322. as R-8610-(G).
  323. If you don't have one of these chips, you should say N here.
  324. config X86_32_NON_STANDARD
  325. bool "Support non-standard 32-bit SMP architectures"
  326. depends on X86_32 && SMP
  327. depends on X86_EXTENDED_PLATFORM
  328. ---help---
  329. This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
  330. subarchitectures. It is intended for a generic binary kernel.
  331. if you select them all, kernel will probe it one by one. and will
  332. fallback to default.
  333. # Alphabetically sorted list of Non standard 32 bit platforms
  334. config X86_NUMAQ
  335. bool "NUMAQ (IBM/Sequent)"
  336. depends on X86_32_NON_STANDARD
  337. select NUMA
  338. select X86_MPPARSE
  339. ---help---
  340. This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
  341. NUMA multiquad box. This changes the way that processors are
  342. bootstrapped, and uses Clustered Logical APIC addressing mode instead
  343. of Flat Logical. You will need a new lynxer.elf file to flash your
  344. firmware with - send email to <Martin.Bligh@us.ibm.com>.
  345. config X86_SUPPORTS_MEMORY_FAILURE
  346. bool
  347. # MCE code calls memory_failure():
  348. depends on X86_MCE
  349. # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
  350. depends on !X86_NUMAQ
  351. # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
  352. depends on X86_64 || !SPARSEMEM
  353. select ARCH_SUPPORTS_MEMORY_FAILURE
  354. default y
  355. config X86_VISWS
  356. bool "SGI 320/540 (Visual Workstation)"
  357. depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
  358. depends on X86_32_NON_STANDARD
  359. ---help---
  360. The SGI Visual Workstation series is an IA32-based workstation
  361. based on SGI systems chips with some legacy PC hardware attached.
  362. Say Y here to create a kernel to run on the SGI 320 or 540.
  363. A kernel compiled for the Visual Workstation will run on general
  364. PCs as well. See <file:Documentation/sgi-visws.txt> for details.
  365. config X86_SUMMIT
  366. bool "Summit/EXA (IBM x440)"
  367. depends on X86_32_NON_STANDARD
  368. ---help---
  369. This option is needed for IBM systems that use the Summit/EXA chipset.
  370. In particular, it is needed for the x440.
  371. config X86_ES7000
  372. bool "Unisys ES7000 IA32 series"
  373. depends on X86_32_NON_STANDARD && X86_BIGSMP
  374. ---help---
  375. Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
  376. supposed to run on an IA32-based Unisys ES7000 system.
  377. config SCHED_OMIT_FRAME_POINTER
  378. def_bool y
  379. prompt "Single-depth WCHAN output"
  380. depends on X86
  381. ---help---
  382. Calculate simpler /proc/<PID>/wchan values. If this option
  383. is disabled then wchan values will recurse back to the
  384. caller function. This provides more accurate wchan values,
  385. at the expense of slightly more scheduling overhead.
  386. If in doubt, say "Y".
  387. menuconfig PARAVIRT_GUEST
  388. bool "Paravirtualized guest support"
  389. ---help---
  390. Say Y here to get to see options related to running Linux under
  391. various hypervisors. This option alone does not add any kernel code.
  392. If you say N, all options in this submenu will be skipped and disabled.
  393. if PARAVIRT_GUEST
  394. source "arch/x86/xen/Kconfig"
  395. config VMI
  396. bool "VMI Guest support"
  397. select PARAVIRT
  398. depends on X86_32
  399. ---help---
  400. VMI provides a paravirtualized interface to the VMware ESX server
  401. (it could be used by other hypervisors in theory too, but is not
  402. at the moment), by linking the kernel to a GPL-ed ROM module
  403. provided by the hypervisor.
  404. config KVM_CLOCK
  405. bool "KVM paravirtualized clock"
  406. select PARAVIRT
  407. select PARAVIRT_CLOCK
  408. ---help---
  409. Turning on this option will allow you to run a paravirtualized clock
  410. when running over the KVM hypervisor. Instead of relying on a PIT
  411. (or probably other) emulation by the underlying device model, the host
  412. provides the guest with timing infrastructure such as time of day, and
  413. system time
  414. config KVM_GUEST
  415. bool "KVM Guest support"
  416. select PARAVIRT
  417. ---help---
  418. This option enables various optimizations for running under the KVM
  419. hypervisor.
  420. source "arch/x86/lguest/Kconfig"
  421. config PARAVIRT
  422. bool "Enable paravirtualization code"
  423. ---help---
  424. This changes the kernel so it can modify itself when it is run
  425. under a hypervisor, potentially improving performance significantly
  426. over full virtualization. However, when run without a hypervisor
  427. the kernel is theoretically slower and slightly larger.
  428. config PARAVIRT_SPINLOCKS
  429. bool "Paravirtualization layer for spinlocks"
  430. depends on PARAVIRT && SMP && EXPERIMENTAL
  431. ---help---
  432. Paravirtualized spinlocks allow a pvops backend to replace the
  433. spinlock implementation with something virtualization-friendly
  434. (for example, block the virtual CPU rather than spinning).
  435. Unfortunately the downside is an up to 5% performance hit on
  436. native kernels, with various workloads.
  437. If you are unsure how to answer this question, answer N.
  438. config PARAVIRT_CLOCK
  439. bool
  440. default n
  441. endif
  442. config PARAVIRT_DEBUG
  443. bool "paravirt-ops debugging"
  444. depends on PARAVIRT && DEBUG_KERNEL
  445. ---help---
  446. Enable to debug paravirt_ops internals. Specifically, BUG if
  447. a paravirt_op is missing when it is called.
  448. config MEMTEST
  449. bool "Memtest"
  450. ---help---
  451. This option adds a kernel parameter 'memtest', which allows memtest
  452. to be set.
  453. memtest=0, mean disabled; -- default
  454. memtest=1, mean do 1 test pattern;
  455. ...
  456. memtest=4, mean do 4 test patterns.
  457. If you are unsure how to answer this question, answer N.
  458. config X86_SUMMIT_NUMA
  459. def_bool y
  460. depends on X86_32 && NUMA && X86_32_NON_STANDARD
  461. config X86_CYCLONE_TIMER
  462. def_bool y
  463. depends on X86_32_NON_STANDARD
  464. source "arch/x86/Kconfig.cpu"
  465. config HPET_TIMER
  466. def_bool X86_64
  467. prompt "HPET Timer Support" if X86_32
  468. ---help---
  469. Use the IA-PC HPET (High Precision Event Timer) to manage
  470. time in preference to the PIT and RTC, if a HPET is
  471. present.
  472. HPET is the next generation timer replacing legacy 8254s.
  473. The HPET provides a stable time base on SMP
  474. systems, unlike the TSC, but it is more expensive to access,
  475. as it is off-chip. You can find the HPET spec at
  476. <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
  477. You can safely choose Y here. However, HPET will only be
  478. activated if the platform and the BIOS support this feature.
  479. Otherwise the 8254 will be used for timing services.
  480. Choose N to continue using the legacy 8254 timer.
  481. config HPET_EMULATE_RTC
  482. def_bool y
  483. depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
  484. # Mark as embedded because too many people got it wrong.
  485. # The code disables itself when not needed.
  486. config DMI
  487. default y
  488. bool "Enable DMI scanning" if EMBEDDED
  489. ---help---
  490. Enabled scanning of DMI to identify machine quirks. Say Y
  491. here unless you have verified that your setup is not
  492. affected by entries in the DMI blacklist. Required by PNP
  493. BIOS code.
  494. config GART_IOMMU
  495. bool "GART IOMMU support" if EMBEDDED
  496. default y
  497. select SWIOTLB
  498. depends on X86_64 && PCI
  499. ---help---
  500. Support for full DMA access of devices with 32bit memory access only
  501. on systems with more than 3GB. This is usually needed for USB,
  502. sound, many IDE/SATA chipsets and some other devices.
  503. Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
  504. based hardware IOMMU and a software bounce buffer based IOMMU used
  505. on Intel systems and as fallback.
  506. The code is only active when needed (enough memory and limited
  507. device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
  508. too.
  509. config CALGARY_IOMMU
  510. bool "IBM Calgary IOMMU support"
  511. select SWIOTLB
  512. depends on X86_64 && PCI && EXPERIMENTAL
  513. ---help---
  514. Support for hardware IOMMUs in IBM's xSeries x366 and x460
  515. systems. Needed to run systems with more than 3GB of memory
  516. properly with 32-bit PCI devices that do not support DAC
  517. (Double Address Cycle). Calgary also supports bus level
  518. isolation, where all DMAs pass through the IOMMU. This
  519. prevents them from going anywhere except their intended
  520. destination. This catches hard-to-find kernel bugs and
  521. mis-behaving drivers and devices that do not use the DMA-API
  522. properly to set up their DMA buffers. The IOMMU can be
  523. turned off at boot time with the iommu=off parameter.
  524. Normally the kernel will make the right choice by itself.
  525. If unsure, say Y.
  526. config CALGARY_IOMMU_ENABLED_BY_DEFAULT
  527. def_bool y
  528. prompt "Should Calgary be enabled by default?"
  529. depends on CALGARY_IOMMU
  530. ---help---
  531. Should Calgary be enabled by default? if you choose 'y', Calgary
  532. will be used (if it exists). If you choose 'n', Calgary will not be
  533. used even if it exists. If you choose 'n' and would like to use
  534. Calgary anyway, pass 'iommu=calgary' on the kernel command line.
  535. If unsure, say Y.
  536. config AMD_IOMMU
  537. bool "AMD IOMMU support"
  538. select SWIOTLB
  539. select PCI_MSI
  540. depends on X86_64 && PCI && ACPI
  541. ---help---
  542. With this option you can enable support for AMD IOMMU hardware in
  543. your system. An IOMMU is a hardware component which provides
  544. remapping of DMA memory accesses from devices. With an AMD IOMMU you
  545. can isolate the the DMA memory of different devices and protect the
  546. system from misbehaving device drivers or hardware.
  547. You can find out if your system has an AMD IOMMU if you look into
  548. your BIOS for an option to enable it or if you have an IVRS ACPI
  549. table.
  550. config AMD_IOMMU_STATS
  551. bool "Export AMD IOMMU statistics to debugfs"
  552. depends on AMD_IOMMU
  553. select DEBUG_FS
  554. ---help---
  555. This option enables code in the AMD IOMMU driver to collect various
  556. statistics about whats happening in the driver and exports that
  557. information to userspace via debugfs.
  558. If unsure, say N.
  559. # need this always selected by IOMMU for the VIA workaround
  560. config SWIOTLB
  561. def_bool y if X86_64
  562. ---help---
  563. Support for software bounce buffers used on x86-64 systems
  564. which don't have a hardware IOMMU (e.g. the current generation
  565. of Intel's x86-64 CPUs). Using this PCI devices which can only
  566. access 32-bits of memory can be used on systems with more than
  567. 3 GB of memory. If unsure, say Y.
  568. config IOMMU_HELPER
  569. def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
  570. config IOMMU_API
  571. def_bool (AMD_IOMMU || DMAR)
  572. config MAXSMP
  573. bool "Configure Maximum number of SMP Processors and NUMA Nodes"
  574. depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
  575. select CPUMASK_OFFSTACK
  576. default n
  577. ---help---
  578. Configure maximum number of CPUS and NUMA Nodes for this architecture.
  579. If unsure, say N.
  580. config NR_CPUS
  581. int "Maximum number of CPUs" if SMP && !MAXSMP
  582. range 2 8 if SMP && X86_32 && !X86_BIGSMP
  583. range 2 512 if SMP && !MAXSMP
  584. default "1" if !SMP
  585. default "4096" if MAXSMP
  586. default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
  587. default "8" if SMP
  588. ---help---
  589. This allows you to specify the maximum number of CPUs which this
  590. kernel will support. The maximum supported value is 512 and the
  591. minimum value which makes sense is 2.
  592. This is purely to save memory - each supported CPU adds
  593. approximately eight kilobytes to the kernel image.
  594. config SCHED_SMT
  595. bool "SMT (Hyperthreading) scheduler support"
  596. depends on X86_HT
  597. ---help---
  598. SMT scheduler support improves the CPU scheduler's decision making
  599. when dealing with Intel Pentium 4 chips with HyperThreading at a
  600. cost of slightly increased overhead in some places. If unsure say
  601. N here.
  602. config SCHED_MC
  603. def_bool y
  604. prompt "Multi-core scheduler support"
  605. depends on X86_HT
  606. ---help---
  607. Multi-core scheduler support improves the CPU scheduler's decision
  608. making when dealing with multi-core CPU chips at a cost of slightly
  609. increased overhead in some places. If unsure say N here.
  610. source "kernel/Kconfig.preempt"
  611. config X86_UP_APIC
  612. bool "Local APIC support on uniprocessors"
  613. depends on X86_32 && !SMP && !X86_32_NON_STANDARD
  614. ---help---
  615. A local APIC (Advanced Programmable Interrupt Controller) is an
  616. integrated interrupt controller in the CPU. If you have a single-CPU
  617. system which has a processor with a local APIC, you can say Y here to
  618. enable and use it. If you say Y here even though your machine doesn't
  619. have a local APIC, then the kernel will still run with no slowdown at
  620. all. The local APIC supports CPU-generated self-interrupts (timer,
  621. performance counters), and the NMI watchdog which detects hard
  622. lockups.
  623. config X86_UP_IOAPIC
  624. bool "IO-APIC support on uniprocessors"
  625. depends on X86_UP_APIC
  626. ---help---
  627. An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
  628. SMP-capable replacement for PC-style interrupt controllers. Most
  629. SMP systems and many recent uniprocessor systems have one.
  630. If you have a single-CPU system with an IO-APIC, you can say Y here
  631. to use it. If you say Y here even though your machine doesn't have
  632. an IO-APIC, then the kernel will still run with no slowdown at all.
  633. config X86_LOCAL_APIC
  634. def_bool y
  635. depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
  636. config X86_IO_APIC
  637. def_bool y
  638. depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
  639. config X86_VISWS_APIC
  640. def_bool y
  641. depends on X86_32 && X86_VISWS
  642. config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
  643. bool "Reroute for broken boot IRQs"
  644. default n
  645. depends on X86_IO_APIC
  646. ---help---
  647. This option enables a workaround that fixes a source of
  648. spurious interrupts. This is recommended when threaded
  649. interrupt handling is used on systems where the generation of
  650. superfluous "boot interrupts" cannot be disabled.
  651. Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
  652. entry in the chipset's IO-APIC is masked (as, e.g. the RT
  653. kernel does during interrupt handling). On chipsets where this
  654. boot IRQ generation cannot be disabled, this workaround keeps
  655. the original IRQ line masked so that only the equivalent "boot
  656. IRQ" is delivered to the CPUs. The workaround also tells the
  657. kernel to set up the IRQ handler on the boot IRQ line. In this
  658. way only one interrupt is delivered to the kernel. Otherwise
  659. the spurious second interrupt may cause the kernel to bring
  660. down (vital) interrupt lines.
  661. Only affects "broken" chipsets. Interrupt sharing may be
  662. increased on these systems.
  663. config X86_MCE
  664. bool "Machine Check / overheating reporting"
  665. ---help---
  666. Machine Check support allows the processor to notify the
  667. kernel if it detects a problem (e.g. overheating, data corruption).
  668. The action the kernel takes depends on the severity of the problem,
  669. ranging from warning messages to halting the machine.
  670. config X86_MCE_INTEL
  671. def_bool y
  672. prompt "Intel MCE features"
  673. depends on X86_MCE && X86_LOCAL_APIC
  674. ---help---
  675. Additional support for intel specific MCE features such as
  676. the thermal monitor.
  677. config X86_MCE_AMD
  678. def_bool y
  679. prompt "AMD MCE features"
  680. depends on X86_MCE && X86_LOCAL_APIC
  681. ---help---
  682. Additional support for AMD specific MCE features such as
  683. the DRAM Error Threshold.
  684. config X86_ANCIENT_MCE
  685. def_bool n
  686. depends on X86_32 && X86_MCE
  687. prompt "Support for old Pentium 5 / WinChip machine checks"
  688. ---help---
  689. Include support for machine check handling on old Pentium 5 or WinChip
  690. systems. These typically need to be enabled explicitely on the command
  691. line.
  692. config X86_MCE_THRESHOLD
  693. depends on X86_MCE_AMD || X86_MCE_INTEL
  694. bool
  695. default y
  696. config X86_MCE_INJECT
  697. depends on X86_MCE
  698. tristate "Machine check injector support"
  699. ---help---
  700. Provide support for injecting machine checks for testing purposes.
  701. If you don't know what a machine check is and you don't do kernel
  702. QA it is safe to say n.
  703. config X86_THERMAL_VECTOR
  704. def_bool y
  705. depends on X86_MCE_INTEL
  706. config VM86
  707. bool "Enable VM86 support" if EMBEDDED
  708. default y
  709. depends on X86_32
  710. ---help---
  711. This option is required by programs like DOSEMU to run 16-bit legacy
  712. code on X86 processors. It also may be needed by software like
  713. XFree86 to initialize some video cards via BIOS. Disabling this
  714. option saves about 6k.
  715. config TOSHIBA
  716. tristate "Toshiba Laptop support"
  717. depends on X86_32
  718. ---help---
  719. This adds a driver to safely access the System Management Mode of
  720. the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
  721. not work on models with a Phoenix BIOS. The System Management Mode
  722. is used to set the BIOS and power saving options on Toshiba portables.
  723. For information on utilities to make use of this driver see the
  724. Toshiba Linux utilities web site at:
  725. <http://www.buzzard.org.uk/toshiba/>.
  726. Say Y if you intend to run this kernel on a Toshiba portable.
  727. Say N otherwise.
  728. config I8K
  729. tristate "Dell laptop support"
  730. ---help---
  731. This adds a driver to safely access the System Management Mode
  732. of the CPU on the Dell Inspiron 8000. The System Management Mode
  733. is used to read cpu temperature and cooling fan status and to
  734. control the fans on the I8K portables.
  735. This driver has been tested only on the Inspiron 8000 but it may
  736. also work with other Dell laptops. You can force loading on other
  737. models by passing the parameter `force=1' to the module. Use at
  738. your own risk.
  739. For information on utilities to make use of this driver see the
  740. I8K Linux utilities web site at:
  741. <http://people.debian.org/~dz/i8k/>
  742. Say Y if you intend to run this kernel on a Dell Inspiron 8000.
  743. Say N otherwise.
  744. config X86_REBOOTFIXUPS
  745. bool "Enable X86 board specific fixups for reboot"
  746. depends on X86_32
  747. ---help---
  748. This enables chipset and/or board specific fixups to be done
  749. in order to get reboot to work correctly. This is only needed on
  750. some combinations of hardware and BIOS. The symptom, for which
  751. this config is intended, is when reboot ends with a stalled/hung
  752. system.
  753. Currently, the only fixup is for the Geode machines using
  754. CS5530A and CS5536 chipsets and the RDC R-321x SoC.
  755. Say Y if you want to enable the fixup. Currently, it's safe to
  756. enable this option even if you don't need it.
  757. Say N otherwise.
  758. config MICROCODE
  759. tristate "/dev/cpu/microcode - microcode support"
  760. select FW_LOADER
  761. ---help---
  762. If you say Y here, you will be able to update the microcode on
  763. certain Intel and AMD processors. The Intel support is for the
  764. IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
  765. Pentium 4, Xeon etc. The AMD support is for family 0x10 and
  766. 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
  767. You will obviously need the actual microcode binary data itself
  768. which is not shipped with the Linux kernel.
  769. This option selects the general module only, you need to select
  770. at least one vendor specific module as well.
  771. To compile this driver as a module, choose M here: the
  772. module will be called microcode.
  773. config MICROCODE_INTEL
  774. bool "Intel microcode patch loading support"
  775. depends on MICROCODE
  776. default MICROCODE
  777. select FW_LOADER
  778. ---help---
  779. This options enables microcode patch loading support for Intel
  780. processors.
  781. For latest news and information on obtaining all the required
  782. Intel ingredients for this driver, check:
  783. <http://www.urbanmyth.org/microcode/>.
  784. config MICROCODE_AMD
  785. bool "AMD microcode patch loading support"
  786. depends on MICROCODE
  787. select FW_LOADER
  788. ---help---
  789. If you select this option, microcode patch loading support for AMD
  790. processors will be enabled.
  791. config MICROCODE_OLD_INTERFACE
  792. def_bool y
  793. depends on MICROCODE
  794. config X86_MSR
  795. tristate "/dev/cpu/*/msr - Model-specific register support"
  796. ---help---
  797. This device gives privileged processes access to the x86
  798. Model-Specific Registers (MSRs). It is a character device with
  799. major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
  800. MSR accesses are directed to a specific CPU on multi-processor
  801. systems.
  802. config X86_CPUID
  803. tristate "/dev/cpu/*/cpuid - CPU information support"
  804. ---help---
  805. This device gives processes access to the x86 CPUID instruction to
  806. be executed on a specific processor. It is a character device
  807. with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
  808. /dev/cpu/31/cpuid.
  809. config X86_CPU_DEBUG
  810. tristate "/sys/kernel/debug/x86/cpu/* - CPU Debug support"
  811. ---help---
  812. If you select this option, this will provide various x86 CPUs
  813. information through debugfs.
  814. choice
  815. prompt "High Memory Support"
  816. default HIGHMEM4G if !X86_NUMAQ
  817. default HIGHMEM64G if X86_NUMAQ
  818. depends on X86_32
  819. config NOHIGHMEM
  820. bool "off"
  821. depends on !X86_NUMAQ
  822. ---help---
  823. Linux can use up to 64 Gigabytes of physical memory on x86 systems.
  824. However, the address space of 32-bit x86 processors is only 4
  825. Gigabytes large. That means that, if you have a large amount of
  826. physical memory, not all of it can be "permanently mapped" by the
  827. kernel. The physical memory that's not permanently mapped is called
  828. "high memory".
  829. If you are compiling a kernel which will never run on a machine with
  830. more than 1 Gigabyte total physical RAM, answer "off" here (default
  831. choice and suitable for most users). This will result in a "3GB/1GB"
  832. split: 3GB are mapped so that each process sees a 3GB virtual memory
  833. space and the remaining part of the 4GB virtual memory space is used
  834. by the kernel to permanently map as much physical memory as
  835. possible.
  836. If the machine has between 1 and 4 Gigabytes physical RAM, then
  837. answer "4GB" here.
  838. If more than 4 Gigabytes is used then answer "64GB" here. This
  839. selection turns Intel PAE (Physical Address Extension) mode on.
  840. PAE implements 3-level paging on IA32 processors. PAE is fully
  841. supported by Linux, PAE mode is implemented on all recent Intel
  842. processors (Pentium Pro and better). NOTE: If you say "64GB" here,
  843. then the kernel will not boot on CPUs that don't support PAE!
  844. The actual amount of total physical memory will either be
  845. auto detected or can be forced by using a kernel command line option
  846. such as "mem=256M". (Try "man bootparam" or see the documentation of
  847. your boot loader (lilo or loadlin) about how to pass options to the
  848. kernel at boot time.)
  849. If unsure, say "off".
  850. config HIGHMEM4G
  851. bool "4GB"
  852. depends on !X86_NUMAQ
  853. ---help---
  854. Select this if you have a 32-bit processor and between 1 and 4
  855. gigabytes of physical RAM.
  856. config HIGHMEM64G
  857. bool "64GB"
  858. depends on !M386 && !M486
  859. select X86_PAE
  860. ---help---
  861. Select this if you have a 32-bit processor and more than 4
  862. gigabytes of physical RAM.
  863. endchoice
  864. choice
  865. depends on EXPERIMENTAL
  866. prompt "Memory split" if EMBEDDED
  867. default VMSPLIT_3G
  868. depends on X86_32
  869. ---help---
  870. Select the desired split between kernel and user memory.
  871. If the address range available to the kernel is less than the
  872. physical memory installed, the remaining memory will be available
  873. as "high memory". Accessing high memory is a little more costly
  874. than low memory, as it needs to be mapped into the kernel first.
  875. Note that increasing the kernel address space limits the range
  876. available to user programs, making the address space there
  877. tighter. Selecting anything other than the default 3G/1G split
  878. will also likely make your kernel incompatible with binary-only
  879. kernel modules.
  880. If you are not absolutely sure what you are doing, leave this
  881. option alone!
  882. config VMSPLIT_3G
  883. bool "3G/1G user/kernel split"
  884. config VMSPLIT_3G_OPT
  885. depends on !X86_PAE
  886. bool "3G/1G user/kernel split (for full 1G low memory)"
  887. config VMSPLIT_2G
  888. bool "2G/2G user/kernel split"
  889. config VMSPLIT_2G_OPT
  890. depends on !X86_PAE
  891. bool "2G/2G user/kernel split (for full 2G low memory)"
  892. config VMSPLIT_1G
  893. bool "1G/3G user/kernel split"
  894. endchoice
  895. config PAGE_OFFSET
  896. hex
  897. default 0xB0000000 if VMSPLIT_3G_OPT
  898. default 0x80000000 if VMSPLIT_2G
  899. default 0x78000000 if VMSPLIT_2G_OPT
  900. default 0x40000000 if VMSPLIT_1G
  901. default 0xC0000000
  902. depends on X86_32
  903. config HIGHMEM
  904. def_bool y
  905. depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
  906. config X86_PAE
  907. bool "PAE (Physical Address Extension) Support"
  908. depends on X86_32 && !HIGHMEM4G
  909. ---help---
  910. PAE is required for NX support, and furthermore enables
  911. larger swapspace support for non-overcommit purposes. It
  912. has the cost of more pagetable lookup overhead, and also
  913. consumes more pagetable space per process.
  914. config ARCH_PHYS_ADDR_T_64BIT
  915. def_bool X86_64 || X86_PAE
  916. config DIRECT_GBPAGES
  917. bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
  918. default y
  919. depends on X86_64
  920. ---help---
  921. Allow the kernel linear mapping to use 1GB pages on CPUs that
  922. support it. This can improve the kernel's performance a tiny bit by
  923. reducing TLB pressure. If in doubt, say "Y".
  924. # Common NUMA Features
  925. config NUMA
  926. bool "Numa Memory Allocation and Scheduler Support"
  927. depends on SMP
  928. depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
  929. default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
  930. ---help---
  931. Enable NUMA (Non Uniform Memory Access) support.
  932. The kernel will try to allocate memory used by a CPU on the
  933. local memory controller of the CPU and add some more
  934. NUMA awareness to the kernel.
  935. For 64-bit this is recommended if the system is Intel Core i7
  936. (or later), AMD Opteron, or EM64T NUMA.
  937. For 32-bit this is only needed on (rare) 32-bit-only platforms
  938. that support NUMA topologies, such as NUMAQ / Summit, or if you
  939. boot a 32-bit kernel on a 64-bit NUMA platform.
  940. Otherwise, you should say N.
  941. comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
  942. depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
  943. config K8_NUMA
  944. def_bool y
  945. prompt "Old style AMD Opteron NUMA detection"
  946. depends on X86_64 && NUMA && PCI
  947. ---help---
  948. Enable K8 NUMA node topology detection. You should say Y here if
  949. you have a multi processor AMD K8 system. This uses an old
  950. method to read the NUMA configuration directly from the builtin
  951. Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
  952. instead, which also takes priority if both are compiled in.
  953. config X86_64_ACPI_NUMA
  954. def_bool y
  955. prompt "ACPI NUMA detection"
  956. depends on X86_64 && NUMA && ACPI && PCI
  957. select ACPI_NUMA
  958. ---help---
  959. Enable ACPI SRAT based node topology detection.
  960. # Some NUMA nodes have memory ranges that span
  961. # other nodes. Even though a pfn is valid and
  962. # between a node's start and end pfns, it may not
  963. # reside on that node. See memmap_init_zone()
  964. # for details.
  965. config NODES_SPAN_OTHER_NODES
  966. def_bool y
  967. depends on X86_64_ACPI_NUMA
  968. config NUMA_EMU
  969. bool "NUMA emulation"
  970. depends on X86_64 && NUMA
  971. ---help---
  972. Enable NUMA emulation. A flat machine will be split
  973. into virtual nodes when booted with "numa=fake=N", where N is the
  974. number of nodes. This is only useful for debugging.
  975. config NODES_SHIFT
  976. int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
  977. range 1 9
  978. default "9" if MAXSMP
  979. default "6" if X86_64
  980. default "4" if X86_NUMAQ
  981. default "3"
  982. depends on NEED_MULTIPLE_NODES
  983. ---help---
  984. Specify the maximum number of NUMA Nodes available on the target
  985. system. Increases memory reserved to accommodate various tables.
  986. config HAVE_ARCH_BOOTMEM
  987. def_bool y
  988. depends on X86_32 && NUMA
  989. config ARCH_HAVE_MEMORY_PRESENT
  990. def_bool y
  991. depends on X86_32 && DISCONTIGMEM
  992. config NEED_NODE_MEMMAP_SIZE
  993. def_bool y
  994. depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
  995. config HAVE_ARCH_ALLOC_REMAP
  996. def_bool y
  997. depends on X86_32 && NUMA
  998. config ARCH_FLATMEM_ENABLE
  999. def_bool y
  1000. depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
  1001. config ARCH_DISCONTIGMEM_ENABLE
  1002. def_bool y
  1003. depends on NUMA && X86_32
  1004. config ARCH_DISCONTIGMEM_DEFAULT
  1005. def_bool y
  1006. depends on NUMA && X86_32
  1007. config ARCH_PROC_KCORE_TEXT
  1008. def_bool y
  1009. depends on X86_64 && PROC_KCORE
  1010. config ARCH_SPARSEMEM_DEFAULT
  1011. def_bool y
  1012. depends on X86_64
  1013. config ARCH_SPARSEMEM_ENABLE
  1014. def_bool y
  1015. depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
  1016. select SPARSEMEM_STATIC if X86_32
  1017. select SPARSEMEM_VMEMMAP_ENABLE if X86_64
  1018. config ARCH_SELECT_MEMORY_MODEL
  1019. def_bool y
  1020. depends on ARCH_SPARSEMEM_ENABLE
  1021. config ARCH_MEMORY_PROBE
  1022. def_bool X86_64
  1023. depends on MEMORY_HOTPLUG
  1024. source "mm/Kconfig"
  1025. config HIGHPTE
  1026. bool "Allocate 3rd-level pagetables from highmem"
  1027. depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
  1028. ---help---
  1029. The VM uses one page table entry for each page of physical memory.
  1030. For systems with a lot of RAM, this can be wasteful of precious
  1031. low memory. Setting this option will put user-space page table
  1032. entries in high memory.
  1033. config X86_CHECK_BIOS_CORRUPTION
  1034. bool "Check for low memory corruption"
  1035. ---help---
  1036. Periodically check for memory corruption in low memory, which
  1037. is suspected to be caused by BIOS. Even when enabled in the
  1038. configuration, it is disabled at runtime. Enable it by
  1039. setting "memory_corruption_check=1" on the kernel command
  1040. line. By default it scans the low 64k of memory every 60
  1041. seconds; see the memory_corruption_check_size and
  1042. memory_corruption_check_period parameters in
  1043. Documentation/kernel-parameters.txt to adjust this.
  1044. When enabled with the default parameters, this option has
  1045. almost no overhead, as it reserves a relatively small amount
  1046. of memory and scans it infrequently. It both detects corruption
  1047. and prevents it from affecting the running system.
  1048. It is, however, intended as a diagnostic tool; if repeatable
  1049. BIOS-originated corruption always affects the same memory,
  1050. you can use memmap= to prevent the kernel from using that
  1051. memory.
  1052. config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
  1053. bool "Set the default setting of memory_corruption_check"
  1054. depends on X86_CHECK_BIOS_CORRUPTION
  1055. default y
  1056. ---help---
  1057. Set whether the default state of memory_corruption_check is
  1058. on or off.
  1059. config X86_RESERVE_LOW_64K
  1060. bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
  1061. default y
  1062. ---help---
  1063. Reserve the first 64K of physical RAM on BIOSes that are known
  1064. to potentially corrupt that memory range. A numbers of BIOSes are
  1065. known to utilize this area during suspend/resume, so it must not
  1066. be used by the kernel.
  1067. Set this to N if you are absolutely sure that you trust the BIOS
  1068. to get all its memory reservations and usages right.
  1069. If you have doubts about the BIOS (e.g. suspend/resume does not
  1070. work or there's kernel crashes after certain hardware hotplug
  1071. events) and it's not AMI or Phoenix, then you might want to enable
  1072. X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
  1073. corruption patterns.
  1074. Say Y if unsure.
  1075. config MATH_EMULATION
  1076. bool
  1077. prompt "Math emulation" if X86_32
  1078. ---help---
  1079. Linux can emulate a math coprocessor (used for floating point
  1080. operations) if you don't have one. 486DX and Pentium processors have
  1081. a math coprocessor built in, 486SX and 386 do not, unless you added
  1082. a 487DX or 387, respectively. (The messages during boot time can
  1083. give you some hints here ["man dmesg"].) Everyone needs either a
  1084. coprocessor or this emulation.
  1085. If you don't have a math coprocessor, you need to say Y here; if you
  1086. say Y here even though you have a coprocessor, the coprocessor will
  1087. be used nevertheless. (This behavior can be changed with the kernel
  1088. command line option "no387", which comes handy if your coprocessor
  1089. is broken. Try "man bootparam" or see the documentation of your boot
  1090. loader (lilo or loadlin) about how to pass options to the kernel at
  1091. boot time.) This means that it is a good idea to say Y here if you
  1092. intend to use this kernel on different machines.
  1093. More information about the internals of the Linux math coprocessor
  1094. emulation can be found in <file:arch/x86/math-emu/README>.
  1095. If you are not sure, say Y; apart from resulting in a 66 KB bigger
  1096. kernel, it won't hurt.
  1097. config MTRR
  1098. bool "MTRR (Memory Type Range Register) support"
  1099. ---help---
  1100. On Intel P6 family processors (Pentium Pro, Pentium II and later)
  1101. the Memory Type Range Registers (MTRRs) may be used to control
  1102. processor access to memory ranges. This is most useful if you have
  1103. a video (VGA) card on a PCI or AGP bus. Enabling write-combining
  1104. allows bus write transfers to be combined into a larger transfer
  1105. before bursting over the PCI/AGP bus. This can increase performance
  1106. of image write operations 2.5 times or more. Saying Y here creates a
  1107. /proc/mtrr file which may be used to manipulate your processor's
  1108. MTRRs. Typically the X server should use this.
  1109. This code has a reasonably generic interface so that similar
  1110. control registers on other processors can be easily supported
  1111. as well:
  1112. The Cyrix 6x86, 6x86MX and M II processors have Address Range
  1113. Registers (ARRs) which provide a similar functionality to MTRRs. For
  1114. these, the ARRs are used to emulate the MTRRs.
  1115. The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
  1116. MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
  1117. write-combining. All of these processors are supported by this code
  1118. and it makes sense to say Y here if you have one of them.
  1119. Saying Y here also fixes a problem with buggy SMP BIOSes which only
  1120. set the MTRRs for the boot CPU and not for the secondary CPUs. This
  1121. can lead to all sorts of problems, so it's good to say Y here.
  1122. You can safely say Y even if your machine doesn't have MTRRs, you'll
  1123. just add about 9 KB to your kernel.
  1124. See <file:Documentation/x86/mtrr.txt> for more information.
  1125. config MTRR_SANITIZER
  1126. def_bool y
  1127. prompt "MTRR cleanup support"
  1128. depends on MTRR
  1129. ---help---
  1130. Convert MTRR layout from continuous to discrete, so X drivers can
  1131. add writeback entries.
  1132. Can be disabled with disable_mtrr_cleanup on the kernel command line.
  1133. The largest mtrr entry size for a continuous block can be set with
  1134. mtrr_chunk_size.
  1135. If unsure, say Y.
  1136. config MTRR_SANITIZER_ENABLE_DEFAULT
  1137. int "MTRR cleanup enable value (0-1)"
  1138. range 0 1
  1139. default "0"
  1140. depends on MTRR_SANITIZER
  1141. ---help---
  1142. Enable mtrr cleanup default value
  1143. config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
  1144. int "MTRR cleanup spare reg num (0-7)"
  1145. range 0 7
  1146. default "1"
  1147. depends on MTRR_SANITIZER
  1148. ---help---
  1149. mtrr cleanup spare entries default, it can be changed via
  1150. mtrr_spare_reg_nr=N on the kernel command line.
  1151. config X86_PAT
  1152. bool
  1153. prompt "x86 PAT support"
  1154. depends on MTRR
  1155. ---help---
  1156. Use PAT attributes to setup page level cache control.
  1157. PATs are the modern equivalents of MTRRs and are much more
  1158. flexible than MTRRs.
  1159. Say N here if you see bootup problems (boot crash, boot hang,
  1160. spontaneous reboots) or a non-working video driver.
  1161. If unsure, say Y.
  1162. config ARCH_USES_PG_UNCACHED
  1163. def_bool y
  1164. depends on X86_PAT
  1165. config EFI
  1166. bool "EFI runtime service support"
  1167. depends on ACPI
  1168. ---help---
  1169. This enables the kernel to use EFI runtime services that are
  1170. available (such as the EFI variable services).
  1171. This option is only useful on systems that have EFI firmware.
  1172. In addition, you should use the latest ELILO loader available
  1173. at <http://elilo.sourceforge.net> in order to take advantage
  1174. of EFI runtime services. However, even with this option, the
  1175. resultant kernel should continue to boot on existing non-EFI
  1176. platforms.
  1177. config SECCOMP
  1178. def_bool y
  1179. prompt "Enable seccomp to safely compute untrusted bytecode"
  1180. ---help---
  1181. This kernel feature is useful for number crunching applications
  1182. that may need to compute untrusted bytecode during their
  1183. execution. By using pipes or other transports made available to
  1184. the process as file descriptors supporting the read/write
  1185. syscalls, it's possible to isolate those applications in
  1186. their own address space using seccomp. Once seccomp is
  1187. enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
  1188. and the task is only allowed to execute a few safe syscalls
  1189. defined by each seccomp mode.
  1190. If unsure, say Y. Only embedded should say N here.
  1191. config CC_STACKPROTECTOR_ALL
  1192. bool
  1193. config CC_STACKPROTECTOR
  1194. bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
  1195. select CC_STACKPROTECTOR_ALL
  1196. ---help---
  1197. This option turns on the -fstack-protector GCC feature. This
  1198. feature puts, at the beginning of functions, a canary value on
  1199. the stack just before the return address, and validates
  1200. the value just before actually returning. Stack based buffer
  1201. overflows (that need to overwrite this return address) now also
  1202. overwrite the canary, which gets detected and the attack is then
  1203. neutralized via a kernel panic.
  1204. This feature requires gcc version 4.2 or above, or a distribution
  1205. gcc with the feature backported. Older versions are automatically
  1206. detected and for those versions, this configuration option is
  1207. ignored. (and a warning is printed during bootup)
  1208. source kernel/Kconfig.hz
  1209. config KEXEC
  1210. bool "kexec system call"
  1211. ---help---
  1212. kexec is a system call that implements the ability to shutdown your
  1213. current kernel, and to start another kernel. It is like a reboot
  1214. but it is independent of the system firmware. And like a reboot
  1215. you can start any kernel with it, not just Linux.
  1216. The name comes from the similarity to the exec system call.
  1217. It is an ongoing process to be certain the hardware in a machine
  1218. is properly shutdown, so do not be surprised if this code does not
  1219. initially work for you. It may help to enable device hotplugging
  1220. support. As of this writing the exact hardware interface is
  1221. strongly in flux, so no good recommendation can be made.
  1222. config CRASH_DUMP
  1223. bool "kernel crash dumps"
  1224. depends on X86_64 || (X86_32 && HIGHMEM)
  1225. ---help---
  1226. Generate crash dump after being started by kexec.
  1227. This should be normally only set in special crash dump kernels
  1228. which are loaded in the main kernel with kexec-tools into
  1229. a specially reserved region and then later executed after
  1230. a crash by kdump/kexec. The crash dump kernel must be compiled
  1231. to a memory address not used by the main kernel or BIOS using
  1232. PHYSICAL_START, or it must be built as a relocatable image
  1233. (CONFIG_RELOCATABLE=y).
  1234. For more details see Documentation/kdump/kdump.txt
  1235. config KEXEC_JUMP
  1236. bool "kexec jump (EXPERIMENTAL)"
  1237. depends on EXPERIMENTAL
  1238. depends on KEXEC && HIBERNATION
  1239. ---help---
  1240. Jump between original kernel and kexeced kernel and invoke
  1241. code in physical address mode via KEXEC
  1242. config PHYSICAL_START
  1243. hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
  1244. default "0x1000000"
  1245. ---help---
  1246. This gives the physical address where the kernel is loaded.
  1247. If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
  1248. bzImage will decompress itself to above physical address and
  1249. run from there. Otherwise, bzImage will run from the address where
  1250. it has been loaded by the boot loader and will ignore above physical
  1251. address.
  1252. In normal kdump cases one does not have to set/change this option
  1253. as now bzImage can be compiled as a completely relocatable image
  1254. (CONFIG_RELOCATABLE=y) and be used to load and run from a different
  1255. address. This option is mainly useful for the folks who don't want
  1256. to use a bzImage for capturing the crash dump and want to use a
  1257. vmlinux instead. vmlinux is not relocatable hence a kernel needs
  1258. to be specifically compiled to run from a specific memory area
  1259. (normally a reserved region) and this option comes handy.
  1260. So if you are using bzImage for capturing the crash dump,
  1261. leave the value here unchanged to 0x1000000 and set
  1262. CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
  1263. for capturing the crash dump change this value to start of
  1264. the reserved region. In other words, it can be set based on
  1265. the "X" value as specified in the "crashkernel=YM@XM"
  1266. command line boot parameter passed to the panic-ed
  1267. kernel. Please take a look at Documentation/kdump/kdump.txt
  1268. for more details about crash dumps.
  1269. Usage of bzImage for capturing the crash dump is recommended as
  1270. one does not have to build two kernels. Same kernel can be used
  1271. as production kernel and capture kernel. Above option should have
  1272. gone away after relocatable bzImage support is introduced. But it
  1273. is present because there are users out there who continue to use
  1274. vmlinux for dump capture. This option should go away down the
  1275. line.
  1276. Don't change this unless you know what you are doing.
  1277. config RELOCATABLE
  1278. bool "Build a relocatable kernel"
  1279. default y
  1280. ---help---
  1281. This builds a kernel image that retains relocation information
  1282. so it can be loaded someplace besides the default 1MB.
  1283. The relocations tend to make the kernel binary about 10% larger,
  1284. but are discarded at runtime.
  1285. One use is for the kexec on panic case where the recovery kernel
  1286. must live at a different physical address than the primary
  1287. kernel.
  1288. Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
  1289. it has been loaded at and the compile time physical address
  1290. (CONFIG_PHYSICAL_START) is ignored.
  1291. # Relocation on x86-32 needs some additional build support
  1292. config X86_NEED_RELOCS
  1293. def_bool y
  1294. depends on X86_32 && RELOCATABLE
  1295. config PHYSICAL_ALIGN
  1296. hex
  1297. prompt "Alignment value to which kernel should be aligned" if X86_32
  1298. default "0x1000000"
  1299. range 0x2000 0x1000000
  1300. ---help---
  1301. This value puts the alignment restrictions on physical address
  1302. where kernel is loaded and run from. Kernel is compiled for an
  1303. address which meets above alignment restriction.
  1304. If bootloader loads the kernel at a non-aligned address and
  1305. CONFIG_RELOCATABLE is set, kernel will move itself to nearest
  1306. address aligned to above value and run from there.
  1307. If bootloader loads the kernel at a non-aligned address and
  1308. CONFIG_RELOCATABLE is not set, kernel will ignore the run time
  1309. load address and decompress itself to the address it has been
  1310. compiled for and run from there. The address for which kernel is
  1311. compiled already meets above alignment restrictions. Hence the
  1312. end result is that kernel runs from a physical address meeting
  1313. above alignment restrictions.
  1314. Don't change this unless you know what you are doing.
  1315. config HOTPLUG_CPU
  1316. bool "Support for hot-pluggable CPUs"
  1317. depends on SMP && HOTPLUG
  1318. ---help---
  1319. Say Y here to allow turning CPUs off and on. CPUs can be
  1320. controlled through /sys/devices/system/cpu.
  1321. ( Note: power management support will enable this option
  1322. automatically on SMP systems. )
  1323. Say N if you want to disable CPU hotplug.
  1324. config COMPAT_VDSO
  1325. def_bool y
  1326. prompt "Compat VDSO support"
  1327. depends on X86_32 || IA32_EMULATION
  1328. ---help---
  1329. Map the 32-bit VDSO to the predictable old-style address too.
  1330. ---help---
  1331. Say N here if you are running a sufficiently recent glibc
  1332. version (2.3.3 or later), to remove the high-mapped
  1333. VDSO mapping and to exclusively use the randomized VDSO.
  1334. If unsure, say Y.
  1335. config CMDLINE_BOOL
  1336. bool "Built-in kernel command line"
  1337. default n
  1338. ---help---
  1339. Allow for specifying boot arguments to the kernel at
  1340. build time. On some systems (e.g. embedded ones), it is
  1341. necessary or convenient to provide some or all of the
  1342. kernel boot arguments with the kernel itself (that is,
  1343. to not rely on the boot loader to provide them.)
  1344. To compile command line arguments into the kernel,
  1345. set this option to 'Y', then fill in the
  1346. the boot arguments in CONFIG_CMDLINE.
  1347. Systems with fully functional boot loaders (i.e. non-embedded)
  1348. should leave this option set to 'N'.
  1349. config CMDLINE
  1350. string "Built-in kernel command string"
  1351. depends on CMDLINE_BOOL
  1352. default ""
  1353. ---help---
  1354. Enter arguments here that should be compiled into the kernel
  1355. image and used at boot time. If the boot loader provides a
  1356. command line at boot time, it is appended to this string to
  1357. form the full kernel command line, when the system boots.
  1358. However, you can use the CONFIG_CMDLINE_OVERRIDE option to
  1359. change this behavior.
  1360. In most cases, the command line (whether built-in or provided
  1361. by the boot loader) should specify the device for the root
  1362. file system.
  1363. config CMDLINE_OVERRIDE
  1364. bool "Built-in command line overrides boot loader arguments"
  1365. default n
  1366. depends on CMDLINE_BOOL
  1367. ---help---
  1368. Set this option to 'Y' to have the kernel ignore the boot loader
  1369. command line, and use ONLY the built-in command line.
  1370. This is used to work around broken boot loaders. This should
  1371. be set to 'N' under normal conditions.
  1372. endmenu
  1373. config ARCH_ENABLE_MEMORY_HOTPLUG
  1374. def_bool y
  1375. depends on X86_64 || (X86_32 && HIGHMEM)
  1376. config ARCH_ENABLE_MEMORY_HOTREMOVE
  1377. def_bool y
  1378. depends on MEMORY_HOTPLUG
  1379. config HAVE_ARCH_EARLY_PFN_TO_NID
  1380. def_bool X86_64
  1381. depends on NUMA
  1382. menu "Power management and ACPI options"
  1383. config ARCH_HIBERNATION_HEADER
  1384. def_bool y
  1385. depends on X86_64 && HIBERNATION
  1386. source "kernel/power/Kconfig"
  1387. source "drivers/acpi/Kconfig"
  1388. source "drivers/sfi/Kconfig"
  1389. config X86_APM_BOOT
  1390. bool
  1391. default y
  1392. depends on APM || APM_MODULE
  1393. menuconfig APM
  1394. tristate "APM (Advanced Power Management) BIOS support"
  1395. depends on X86_32 && PM_SLEEP
  1396. ---help---
  1397. APM is a BIOS specification for saving power using several different
  1398. techniques. This is mostly useful for battery powered laptops with
  1399. APM compliant BIOSes. If you say Y here, the system time will be
  1400. reset after a RESUME operation, the /proc/apm device will provide
  1401. battery status information, and user-space programs will receive
  1402. notification of APM "events" (e.g. battery status change).
  1403. If you select "Y" here, you can disable actual use of the APM
  1404. BIOS by passing the "apm=off" option to the kernel at boot time.
  1405. Note that the APM support is almost completely disabled for
  1406. machines with more than one CPU.
  1407. In order to use APM, you will need supporting software. For location
  1408. and more information, read <file:Documentation/power/pm.txt> and the
  1409. Battery Powered Linux mini-HOWTO, available from
  1410. <http://www.tldp.org/docs.html#howto>.
  1411. This driver does not spin down disk drives (see the hdparm(8)
  1412. manpage ("man 8 hdparm") for that), and it doesn't turn off
  1413. VESA-compliant "green" monitors.
  1414. This driver does not support the TI 4000M TravelMate and the ACER
  1415. 486/DX4/75 because they don't have compliant BIOSes. Many "green"
  1416. desktop machines also don't have compliant BIOSes, and this driver
  1417. may cause those machines to panic during the boot phase.
  1418. Generally, if you don't have a battery in your machine, there isn't
  1419. much point in using this driver and you should say N. If you get
  1420. random kernel OOPSes or reboots that don't seem to be related to
  1421. anything, try disabling/enabling this option (or disabling/enabling
  1422. APM in your BIOS).
  1423. Some other things you should try when experiencing seemingly random,
  1424. "weird" problems:
  1425. 1) make sure that you have enough swap space and that it is
  1426. enabled.
  1427. 2) pass the "no-hlt" option to the kernel
  1428. 3) switch on floating point emulation in the kernel and pass
  1429. the "no387" option to the kernel
  1430. 4) pass the "floppy=nodma" option to the kernel
  1431. 5) pass the "mem=4M" option to the kernel (thereby disabling
  1432. all but the first 4 MB of RAM)
  1433. 6) make sure that the CPU is not over clocked.
  1434. 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
  1435. 8) disable the cache from your BIOS settings
  1436. 9) install a fan for the video card or exchange video RAM
  1437. 10) install a better fan for the CPU
  1438. 11) exchange RAM chips
  1439. 12) exchange the motherboard.
  1440. To compile this driver as a module, choose M here: the
  1441. module will be called apm.
  1442. if APM
  1443. config APM_IGNORE_USER_SUSPEND
  1444. bool "Ignore USER SUSPEND"
  1445. ---help---
  1446. This option will ignore USER SUSPEND requests. On machines with a
  1447. compliant APM BIOS, you want to say N. However, on the NEC Versa M
  1448. series notebooks, it is necessary to say Y because of a BIOS bug.
  1449. config APM_DO_ENABLE
  1450. bool "Enable PM at boot time"
  1451. ---help---
  1452. Enable APM features at boot time. From page 36 of the APM BIOS
  1453. specification: "When disabled, the APM BIOS does not automatically
  1454. power manage devices, enter the Standby State, enter the Suspend
  1455. State, or take power saving steps in response to CPU Idle calls."
  1456. This driver will make CPU Idle calls when Linux is idle (unless this
  1457. feature is turned off -- see "Do CPU IDLE calls", below). This
  1458. should always save battery power, but more complicated APM features
  1459. will be dependent on your BIOS implementation. You may need to turn
  1460. this option off if your computer hangs at boot time when using APM
  1461. support, or if it beeps continuously instead of suspending. Turn
  1462. this off if you have a NEC UltraLite Versa 33/C or a Toshiba
  1463. T400CDT. This is off by default since most machines do fine without
  1464. this feature.
  1465. config APM_CPU_IDLE
  1466. bool "Make CPU Idle calls when idle"
  1467. ---help---
  1468. Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
  1469. On some machines, this can activate improved power savings, such as
  1470. a slowed CPU clock rate, when the machine is idle. These idle calls
  1471. are made after the idle loop has run for some length of time (e.g.,
  1472. 333 mS). On some machines, this will cause a hang at boot time or
  1473. whenever the CPU becomes idle. (On machines with more than one CPU,
  1474. this option does nothing.)
  1475. config APM_DISPLAY_BLANK
  1476. bool "Enable console blanking using APM"
  1477. ---help---
  1478. Enable console blanking using the APM. Some laptops can use this to
  1479. turn off the LCD backlight when the screen blanker of the Linux
  1480. virtual console blanks the screen. Note that this is only used by
  1481. the virtual console screen blanker, and won't turn off the backlight
  1482. when using the X Window system. This also doesn't have anything to
  1483. do with your VESA-compliant power-saving monitor. Further, this
  1484. option doesn't work for all laptops -- it might not turn off your
  1485. backlight at all, or it might print a lot of errors to the console,
  1486. especially if you are using gpm.
  1487. config APM_ALLOW_INTS
  1488. bool "Allow interrupts during APM BIOS calls"
  1489. ---help---
  1490. Normally we disable external interrupts while we are making calls to
  1491. the APM BIOS as a measure to lessen the effects of a badly behaving
  1492. BIOS implementation. The BIOS should reenable interrupts if it
  1493. needs to. Unfortunately, some BIOSes do not -- especially those in
  1494. many of the newer IBM Thinkpads. If you experience hangs when you
  1495. suspend, try setting this to Y. Otherwise, say N.
  1496. endif # APM
  1497. source "arch/x86/kernel/cpu/cpufreq/Kconfig"
  1498. source "drivers/cpuidle/Kconfig"
  1499. source "drivers/idle/Kconfig"
  1500. endmenu
  1501. menu "Bus options (PCI etc.)"
  1502. config PCI
  1503. bool "PCI support"
  1504. default y
  1505. select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
  1506. ---help---
  1507. Find out whether you have a PCI motherboard. PCI is the name of a
  1508. bus system, i.e. the way the CPU talks to the other stuff inside
  1509. your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
  1510. VESA. If you have PCI, say Y, otherwise N.
  1511. choice
  1512. prompt "PCI access mode"
  1513. depends on X86_32 && PCI
  1514. default PCI_GOANY
  1515. ---help---
  1516. On PCI systems, the BIOS can be used to detect the PCI devices and
  1517. determine their configuration. However, some old PCI motherboards
  1518. have BIOS bugs and may crash if this is done. Also, some embedded
  1519. PCI-based systems don't have any BIOS at all. Linux can also try to
  1520. detect the PCI hardware directly without using the BIOS.
  1521. With this option, you can specify how Linux should detect the
  1522. PCI devices. If you choose "BIOS", the BIOS will be used,
  1523. if you choose "Direct", the BIOS won't be used, and if you
  1524. choose "MMConfig", then PCI Express MMCONFIG will be used.
  1525. If you choose "Any", the kernel will try MMCONFIG, then the
  1526. direct access method and falls back to the BIOS if that doesn't
  1527. work. If unsure, go with the default, which is "Any".
  1528. config PCI_GOBIOS
  1529. bool "BIOS"
  1530. config PCI_GOMMCONFIG
  1531. bool "MMConfig"
  1532. config PCI_GODIRECT
  1533. bool "Direct"
  1534. config PCI_GOOLPC
  1535. bool "OLPC"
  1536. depends on OLPC
  1537. config PCI_GOANY
  1538. bool "Any"
  1539. endchoice
  1540. config PCI_BIOS
  1541. def_bool y
  1542. depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
  1543. # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
  1544. config PCI_DIRECT
  1545. def_bool y
  1546. depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
  1547. config PCI_MMCONFIG
  1548. def_bool y
  1549. depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
  1550. config PCI_OLPC
  1551. def_bool y
  1552. depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
  1553. config PCI_DOMAINS
  1554. def_bool y
  1555. depends on PCI
  1556. config PCI_MMCONFIG
  1557. bool "Support mmconfig PCI config space access"
  1558. depends on X86_64 && PCI && ACPI
  1559. config DMAR
  1560. bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
  1561. depends on PCI_MSI && ACPI && EXPERIMENTAL
  1562. help
  1563. DMA remapping (DMAR) devices support enables independent address
  1564. translations for Direct Memory Access (DMA) from devices.
  1565. These DMA remapping devices are reported via ACPI tables
  1566. and include PCI device scope covered by these DMA
  1567. remapping devices.
  1568. config DMAR_DEFAULT_ON
  1569. def_bool y
  1570. prompt "Enable DMA Remapping Devices by default"
  1571. depends on DMAR
  1572. help
  1573. Selecting this option will enable a DMAR device at boot time if
  1574. one is found. If this option is not selected, DMAR support can
  1575. be enabled by passing intel_iommu=on to the kernel. It is
  1576. recommended you say N here while the DMAR code remains
  1577. experimental.
  1578. config DMAR_BROKEN_GFX_WA
  1579. def_bool n
  1580. prompt "Workaround broken graphics drivers (going away soon)"
  1581. depends on DMAR && BROKEN
  1582. ---help---
  1583. Current Graphics drivers tend to use physical address
  1584. for DMA and avoid using DMA APIs. Setting this config
  1585. option permits the IOMMU driver to set a unity map for
  1586. all the OS-visible memory. Hence the driver can continue
  1587. to use physical addresses for DMA, at least until this
  1588. option is removed in the 2.6.32 kernel.
  1589. config DMAR_FLOPPY_WA
  1590. def_bool y
  1591. depends on DMAR
  1592. ---help---
  1593. Floppy disk drivers are known to bypass DMA API calls
  1594. thereby failing to work when IOMMU is enabled. This
  1595. workaround will setup a 1:1 mapping for the first
  1596. 16MiB to make floppy (an ISA device) work.
  1597. config INTR_REMAP
  1598. bool "Support for Interrupt Remapping (EXPERIMENTAL)"
  1599. depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
  1600. ---help---
  1601. Supports Interrupt remapping for IO-APIC and MSI devices.
  1602. To use x2apic mode in the CPU's which support x2APIC enhancements or
  1603. to support platforms with CPU's having > 8 bit APIC ID, say Y.
  1604. source "drivers/pci/pcie/Kconfig"
  1605. source "drivers/pci/Kconfig"
  1606. # x86_64 have no ISA slots, but do have ISA-style DMA.
  1607. config ISA_DMA_API
  1608. def_bool y
  1609. if X86_32
  1610. config ISA
  1611. bool "ISA support"
  1612. ---help---
  1613. Find out whether you have ISA slots on your motherboard. ISA is the
  1614. name of a bus system, i.e. the way the CPU talks to the other stuff
  1615. inside your box. Other bus systems are PCI, EISA, MicroChannel
  1616. (MCA) or VESA. ISA is an older system, now being displaced by PCI;
  1617. newer boards don't support it. If you have ISA, say Y, otherwise N.
  1618. config EISA
  1619. bool "EISA support"
  1620. depends on ISA
  1621. ---help---
  1622. The Extended Industry Standard Architecture (EISA) bus was
  1623. developed as an open alternative to the IBM MicroChannel bus.
  1624. The EISA bus provided some of the features of the IBM MicroChannel
  1625. bus while maintaining backward compatibility with cards made for
  1626. the older ISA bus. The EISA bus saw limited use between 1988 and
  1627. 1995 when it was made obsolete by the PCI bus.
  1628. Say Y here if you are building a kernel for an EISA-based machine.
  1629. Otherwise, say N.
  1630. source "drivers/eisa/Kconfig"
  1631. config MCA
  1632. bool "MCA support"
  1633. ---help---
  1634. MicroChannel Architecture is found in some IBM PS/2 machines and
  1635. laptops. It is a bus system similar to PCI or ISA. See
  1636. <file:Documentation/mca.txt> (and especially the web page given
  1637. there) before attempting to build an MCA bus kernel.
  1638. source "drivers/mca/Kconfig"
  1639. config SCx200
  1640. tristate "NatSemi SCx200 support"
  1641. ---help---
  1642. This provides basic support for National Semiconductor's
  1643. (now AMD's) Geode processors. The driver probes for the
  1644. PCI-IDs of several on-chip devices, so its a good dependency
  1645. for other scx200_* drivers.
  1646. If compiled as a module, the driver is named scx200.
  1647. config SCx200HR_TIMER
  1648. tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
  1649. depends on SCx200 && GENERIC_TIME
  1650. default y
  1651. ---help---
  1652. This driver provides a clocksource built upon the on-chip
  1653. 27MHz high-resolution timer. Its also a workaround for
  1654. NSC Geode SC-1100's buggy TSC, which loses time when the
  1655. processor goes idle (as is done by the scheduler). The
  1656. other workaround is idle=poll boot option.
  1657. config GEODE_MFGPT_TIMER
  1658. def_bool y
  1659. prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
  1660. depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
  1661. ---help---
  1662. This driver provides a clock event source based on the MFGPT
  1663. timer(s) in the CS5535 and CS5536 companion chip for the geode.
  1664. MFGPTs have a better resolution and max interval than the
  1665. generic PIT, and are suitable for use as high-res timers.
  1666. config OLPC
  1667. bool "One Laptop Per Child support"
  1668. default n
  1669. ---help---
  1670. Add support for detecting the unique features of the OLPC
  1671. XO hardware.
  1672. endif # X86_32
  1673. config K8_NB
  1674. def_bool y
  1675. depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
  1676. source "drivers/pcmcia/Kconfig"
  1677. source "drivers/pci/hotplug/Kconfig"
  1678. endmenu
  1679. menu "Executable file formats / Emulations"
  1680. source "fs/Kconfig.binfmt"
  1681. config IA32_EMULATION
  1682. bool "IA32 Emulation"
  1683. depends on X86_64
  1684. select COMPAT_BINFMT_ELF
  1685. ---help---
  1686. Include code to run 32-bit programs under a 64-bit kernel. You should
  1687. likely turn this on, unless you're 100% sure that you don't have any
  1688. 32-bit programs left.
  1689. config IA32_AOUT
  1690. tristate "IA32 a.out support"
  1691. depends on IA32_EMULATION
  1692. ---help---
  1693. Support old a.out binaries in the 32bit emulation.
  1694. config COMPAT
  1695. def_bool y
  1696. depends on IA32_EMULATION
  1697. config COMPAT_FOR_U64_ALIGNMENT
  1698. def_bool COMPAT
  1699. depends on X86_64
  1700. config SYSVIPC_COMPAT
  1701. def_bool y
  1702. depends on COMPAT && SYSVIPC
  1703. endmenu
  1704. config HAVE_ATOMIC_IOMAP
  1705. def_bool y
  1706. depends on X86_32
  1707. source "net/Kconfig"
  1708. source "drivers/Kconfig"
  1709. source "drivers/firmware/Kconfig"
  1710. source "fs/Kconfig"
  1711. source "arch/x86/Kconfig.debug"
  1712. source "security/Kconfig"
  1713. source "crypto/Kconfig"
  1714. source "arch/x86/kvm/Kconfig"
  1715. source "lib/Kconfig"