Kconfig 68 KB

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  1. # Select 32 or 64 bit
  2. config 64BIT
  3. bool "64-bit kernel" if ARCH = "x86"
  4. default ARCH = "x86_64"
  5. ---help---
  6. Say yes to build a 64-bit kernel - formerly known as x86_64
  7. Say no to build a 32-bit kernel - formerly known as i386
  8. config X86_32
  9. def_bool !64BIT
  10. config X86_64
  11. def_bool 64BIT
  12. ### Arch settings
  13. config X86
  14. def_bool y
  15. select HAVE_AOUT if X86_32
  16. select HAVE_READQ
  17. select HAVE_WRITEQ
  18. select HAVE_UNSTABLE_SCHED_CLOCK
  19. select HAVE_IDE
  20. select HAVE_OPROFILE
  21. select HAVE_PERF_EVENTS
  22. select HAVE_IRQ_WORK
  23. select HAVE_IOREMAP_PROT
  24. select HAVE_KPROBES
  25. select HAVE_MEMBLOCK
  26. select ARCH_WANT_OPTIONAL_GPIOLIB
  27. select ARCH_WANT_FRAME_POINTERS
  28. select HAVE_DMA_ATTRS
  29. select HAVE_KRETPROBES
  30. select HAVE_OPTPROBES
  31. select HAVE_FTRACE_MCOUNT_RECORD
  32. select HAVE_C_RECORDMCOUNT
  33. select HAVE_DYNAMIC_FTRACE
  34. select HAVE_FUNCTION_TRACER
  35. select HAVE_FUNCTION_GRAPH_TRACER
  36. select HAVE_FUNCTION_GRAPH_FP_TEST
  37. select HAVE_FUNCTION_TRACE_MCOUNT_TEST
  38. select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
  39. select HAVE_SYSCALL_TRACEPOINTS
  40. select HAVE_KVM
  41. select HAVE_ARCH_KGDB
  42. select HAVE_ARCH_TRACEHOOK
  43. select HAVE_GENERIC_DMA_COHERENT if X86_32
  44. select HAVE_EFFICIENT_UNALIGNED_ACCESS
  45. select USER_STACKTRACE_SUPPORT
  46. select HAVE_REGS_AND_STACK_ACCESS_API
  47. select HAVE_DMA_API_DEBUG
  48. select HAVE_KERNEL_GZIP
  49. select HAVE_KERNEL_BZIP2
  50. select HAVE_KERNEL_LZMA
  51. select HAVE_KERNEL_XZ
  52. select HAVE_KERNEL_LZO
  53. select HAVE_HW_BREAKPOINT
  54. select HAVE_MIXED_BREAKPOINTS_REGS
  55. select PERF_EVENTS
  56. select HAVE_PERF_EVENTS_NMI
  57. select ANON_INODES
  58. select HAVE_ARCH_KMEMCHECK
  59. select HAVE_USER_RETURN_NOTIFIER
  60. select HAVE_ARCH_JUMP_LABEL
  61. select HAVE_TEXT_POKE_SMP
  62. select HAVE_GENERIC_HARDIRQS
  63. select HAVE_SPARSE_IRQ
  64. select GENERIC_FIND_FIRST_BIT
  65. select GENERIC_FIND_NEXT_BIT
  66. select GENERIC_IRQ_PROBE
  67. select GENERIC_PENDING_IRQ if SMP
  68. select GENERIC_IRQ_SHOW
  69. select IRQ_FORCED_THREADING
  70. select USE_GENERIC_SMP_HELPERS if SMP
  71. config INSTRUCTION_DECODER
  72. def_bool (KPROBES || PERF_EVENTS)
  73. config OUTPUT_FORMAT
  74. string
  75. default "elf32-i386" if X86_32
  76. default "elf64-x86-64" if X86_64
  77. config ARCH_DEFCONFIG
  78. string
  79. default "arch/x86/configs/i386_defconfig" if X86_32
  80. default "arch/x86/configs/x86_64_defconfig" if X86_64
  81. config GENERIC_CMOS_UPDATE
  82. def_bool y
  83. config CLOCKSOURCE_WATCHDOG
  84. def_bool y
  85. config GENERIC_CLOCKEVENTS
  86. def_bool y
  87. config GENERIC_CLOCKEVENTS_BROADCAST
  88. def_bool y
  89. depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
  90. config LOCKDEP_SUPPORT
  91. def_bool y
  92. config STACKTRACE_SUPPORT
  93. def_bool y
  94. config HAVE_LATENCYTOP_SUPPORT
  95. def_bool y
  96. config MMU
  97. def_bool y
  98. config ZONE_DMA
  99. def_bool y
  100. config SBUS
  101. bool
  102. config NEED_DMA_MAP_STATE
  103. def_bool (X86_64 || DMAR || DMA_API_DEBUG)
  104. config NEED_SG_DMA_LENGTH
  105. def_bool y
  106. config GENERIC_ISA_DMA
  107. def_bool y
  108. config GENERIC_IOMAP
  109. def_bool y
  110. config GENERIC_BUG
  111. def_bool y
  112. depends on BUG
  113. select GENERIC_BUG_RELATIVE_POINTERS if X86_64
  114. config GENERIC_BUG_RELATIVE_POINTERS
  115. bool
  116. config GENERIC_HWEIGHT
  117. def_bool y
  118. config GENERIC_GPIO
  119. bool
  120. config ARCH_MAY_HAVE_PC_FDC
  121. def_bool y
  122. config RWSEM_GENERIC_SPINLOCK
  123. def_bool !X86_XADD
  124. config RWSEM_XCHGADD_ALGORITHM
  125. def_bool X86_XADD
  126. config ARCH_HAS_CPU_IDLE_WAIT
  127. def_bool y
  128. config GENERIC_CALIBRATE_DELAY
  129. def_bool y
  130. config GENERIC_TIME_VSYSCALL
  131. bool
  132. default X86_64
  133. config ARCH_HAS_CPU_RELAX
  134. def_bool y
  135. config ARCH_HAS_DEFAULT_IDLE
  136. def_bool y
  137. config ARCH_HAS_CACHE_LINE_SIZE
  138. def_bool y
  139. config HAVE_SETUP_PER_CPU_AREA
  140. def_bool y
  141. config NEED_PER_CPU_EMBED_FIRST_CHUNK
  142. def_bool y
  143. config NEED_PER_CPU_PAGE_FIRST_CHUNK
  144. def_bool y
  145. config HAVE_CPUMASK_OF_CPU_MAP
  146. def_bool X86_64_SMP
  147. config ARCH_HIBERNATION_POSSIBLE
  148. def_bool y
  149. config ARCH_SUSPEND_POSSIBLE
  150. def_bool y
  151. config ZONE_DMA32
  152. bool
  153. default X86_64
  154. config ARCH_POPULATES_NODE_MAP
  155. def_bool y
  156. config AUDIT_ARCH
  157. bool
  158. default X86_64
  159. config ARCH_SUPPORTS_OPTIMIZED_INLINING
  160. def_bool y
  161. config ARCH_SUPPORTS_DEBUG_PAGEALLOC
  162. def_bool y
  163. config HAVE_INTEL_TXT
  164. def_bool y
  165. depends on EXPERIMENTAL && DMAR && ACPI
  166. config X86_32_SMP
  167. def_bool y
  168. depends on X86_32 && SMP
  169. config X86_64_SMP
  170. def_bool y
  171. depends on X86_64 && SMP
  172. config X86_HT
  173. def_bool y
  174. depends on SMP
  175. config X86_TRAMPOLINE
  176. def_bool y
  177. depends on SMP || (64BIT && ACPI_SLEEP)
  178. config X86_32_LAZY_GS
  179. def_bool y
  180. depends on X86_32 && !CC_STACKPROTECTOR
  181. config ARCH_HWEIGHT_CFLAGS
  182. string
  183. default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
  184. default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64
  185. config KTIME_SCALAR
  186. def_bool X86_32
  187. config ARCH_CPU_PROBE_RELEASE
  188. def_bool y
  189. depends on HOTPLUG_CPU
  190. source "init/Kconfig"
  191. source "kernel/Kconfig.freezer"
  192. menu "Processor type and features"
  193. source "kernel/time/Kconfig"
  194. config SMP
  195. bool "Symmetric multi-processing support"
  196. ---help---
  197. This enables support for systems with more than one CPU. If you have
  198. a system with only one CPU, like most personal computers, say N. If
  199. you have a system with more than one CPU, say Y.
  200. If you say N here, the kernel will run on single and multiprocessor
  201. machines, but will use only one CPU of a multiprocessor machine. If
  202. you say Y here, the kernel will run on many, but not all,
  203. singleprocessor machines. On a singleprocessor machine, the kernel
  204. will run faster if you say N here.
  205. Note that if you say Y here and choose architecture "586" or
  206. "Pentium" under "Processor family", the kernel will not work on 486
  207. architectures. Similarly, multiprocessor kernels for the "PPro"
  208. architecture may not work on all Pentium based boards.
  209. People using multiprocessor machines who say Y here should also say
  210. Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
  211. Management" code will be disabled if you say Y here.
  212. See also <file:Documentation/i386/IO-APIC.txt>,
  213. <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
  214. <http://www.tldp.org/docs.html#howto>.
  215. If you don't know what to do here, say N.
  216. config X86_X2APIC
  217. bool "Support x2apic"
  218. depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
  219. ---help---
  220. This enables x2apic support on CPUs that have this feature.
  221. This allows 32-bit apic IDs (so it can support very large systems),
  222. and accesses the local apic via MSRs not via mmio.
  223. If you don't know what to do here, say N.
  224. config X86_MPPARSE
  225. bool "Enable MPS table" if ACPI
  226. default y
  227. depends on X86_LOCAL_APIC
  228. ---help---
  229. For old smp systems that do not have proper acpi support. Newer systems
  230. (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
  231. config X86_BIGSMP
  232. bool "Support for big SMP systems with more than 8 CPUs"
  233. depends on X86_32 && SMP
  234. ---help---
  235. This option is needed for the systems that have more than 8 CPUs
  236. if X86_32
  237. config X86_EXTENDED_PLATFORM
  238. bool "Support for extended (non-PC) x86 platforms"
  239. default y
  240. ---help---
  241. If you disable this option then the kernel will only support
  242. standard PC platforms. (which covers the vast majority of
  243. systems out there.)
  244. If you enable this option then you'll be able to select support
  245. for the following (non-PC) 32 bit x86 platforms:
  246. AMD Elan
  247. NUMAQ (IBM/Sequent)
  248. RDC R-321x SoC
  249. SGI 320/540 (Visual Workstation)
  250. Summit/EXA (IBM x440)
  251. Unisys ES7000 IA32 series
  252. Moorestown MID devices
  253. If you have one of these systems, or if you want to build a
  254. generic distribution kernel, say Y here - otherwise say N.
  255. endif
  256. if X86_64
  257. config X86_EXTENDED_PLATFORM
  258. bool "Support for extended (non-PC) x86 platforms"
  259. default y
  260. ---help---
  261. If you disable this option then the kernel will only support
  262. standard PC platforms. (which covers the vast majority of
  263. systems out there.)
  264. If you enable this option then you'll be able to select support
  265. for the following (non-PC) 64 bit x86 platforms:
  266. ScaleMP vSMP
  267. SGI Ultraviolet
  268. If you have one of these systems, or if you want to build a
  269. generic distribution kernel, say Y here - otherwise say N.
  270. endif
  271. # This is an alphabetically sorted list of 64 bit extended platforms
  272. # Please maintain the alphabetic order if and when there are additions
  273. config X86_VSMP
  274. bool "ScaleMP vSMP"
  275. select PARAVIRT_GUEST
  276. select PARAVIRT
  277. depends on X86_64 && PCI
  278. depends on X86_EXTENDED_PLATFORM
  279. ---help---
  280. Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
  281. supposed to run on these EM64T-based machines. Only choose this option
  282. if you have one of these machines.
  283. config X86_UV
  284. bool "SGI Ultraviolet"
  285. depends on X86_64
  286. depends on X86_EXTENDED_PLATFORM
  287. depends on NUMA
  288. depends on X86_X2APIC
  289. ---help---
  290. This option is needed in order to support SGI Ultraviolet systems.
  291. If you don't have one of these, you should say N here.
  292. # Following is an alphabetically sorted list of 32 bit extended platforms
  293. # Please maintain the alphabetic order if and when there are additions
  294. config X86_ELAN
  295. bool "AMD Elan"
  296. depends on X86_32
  297. depends on X86_EXTENDED_PLATFORM
  298. ---help---
  299. Select this for an AMD Elan processor.
  300. Do not use this option for K6/Athlon/Opteron processors!
  301. If unsure, choose "PC-compatible" instead.
  302. config X86_INTEL_CE
  303. bool "CE4100 TV platform"
  304. depends on PCI
  305. depends on PCI_GODIRECT
  306. depends on X86_32
  307. depends on X86_EXTENDED_PLATFORM
  308. select X86_REBOOTFIXUPS
  309. select OF
  310. select OF_EARLY_FLATTREE
  311. ---help---
  312. Select for the Intel CE media processor (CE4100) SOC.
  313. This option compiles in support for the CE4100 SOC for settop
  314. boxes and media devices.
  315. config X86_MRST
  316. bool "Moorestown MID platform"
  317. depends on PCI
  318. depends on PCI_GOANY
  319. depends on X86_32
  320. depends on X86_EXTENDED_PLATFORM
  321. depends on X86_IO_APIC
  322. select APB_TIMER
  323. select I2C
  324. select SPI
  325. select INTEL_SCU_IPC
  326. select X86_PLATFORM_DEVICES
  327. ---help---
  328. Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
  329. Internet Device(MID) platform. Moorestown consists of two chips:
  330. Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
  331. Unlike standard x86 PCs, Moorestown does not have many legacy devices
  332. nor standard legacy replacement devices/features. e.g. Moorestown does
  333. not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
  334. config X86_RDC321X
  335. bool "RDC R-321x SoC"
  336. depends on X86_32
  337. depends on X86_EXTENDED_PLATFORM
  338. select M486
  339. select X86_REBOOTFIXUPS
  340. ---help---
  341. This option is needed for RDC R-321x system-on-chip, also known
  342. as R-8610-(G).
  343. If you don't have one of these chips, you should say N here.
  344. config X86_32_NON_STANDARD
  345. bool "Support non-standard 32-bit SMP architectures"
  346. depends on X86_32 && SMP
  347. depends on X86_EXTENDED_PLATFORM
  348. ---help---
  349. This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
  350. subarchitectures. It is intended for a generic binary kernel.
  351. if you select them all, kernel will probe it one by one. and will
  352. fallback to default.
  353. # Alphabetically sorted list of Non standard 32 bit platforms
  354. config X86_NUMAQ
  355. bool "NUMAQ (IBM/Sequent)"
  356. depends on X86_32_NON_STANDARD
  357. depends on PCI
  358. select NUMA
  359. select X86_MPPARSE
  360. ---help---
  361. This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
  362. NUMA multiquad box. This changes the way that processors are
  363. bootstrapped, and uses Clustered Logical APIC addressing mode instead
  364. of Flat Logical. You will need a new lynxer.elf file to flash your
  365. firmware with - send email to <Martin.Bligh@us.ibm.com>.
  366. config X86_SUPPORTS_MEMORY_FAILURE
  367. def_bool y
  368. # MCE code calls memory_failure():
  369. depends on X86_MCE
  370. # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
  371. depends on !X86_NUMAQ
  372. # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
  373. depends on X86_64 || !SPARSEMEM
  374. select ARCH_SUPPORTS_MEMORY_FAILURE
  375. config X86_VISWS
  376. bool "SGI 320/540 (Visual Workstation)"
  377. depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
  378. depends on X86_32_NON_STANDARD
  379. ---help---
  380. The SGI Visual Workstation series is an IA32-based workstation
  381. based on SGI systems chips with some legacy PC hardware attached.
  382. Say Y here to create a kernel to run on the SGI 320 or 540.
  383. A kernel compiled for the Visual Workstation will run on general
  384. PCs as well. See <file:Documentation/sgi-visws.txt> for details.
  385. config X86_SUMMIT
  386. bool "Summit/EXA (IBM x440)"
  387. depends on X86_32_NON_STANDARD
  388. ---help---
  389. This option is needed for IBM systems that use the Summit/EXA chipset.
  390. In particular, it is needed for the x440.
  391. config X86_ES7000
  392. bool "Unisys ES7000 IA32 series"
  393. depends on X86_32_NON_STANDARD && X86_BIGSMP
  394. ---help---
  395. Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
  396. supposed to run on an IA32-based Unisys ES7000 system.
  397. config X86_32_IRIS
  398. tristate "Eurobraille/Iris poweroff module"
  399. depends on X86_32
  400. ---help---
  401. The Iris machines from EuroBraille do not have APM or ACPI support
  402. to shut themselves down properly. A special I/O sequence is
  403. needed to do so, which is what this module does at
  404. kernel shutdown.
  405. This is only for Iris machines from EuroBraille.
  406. If unused, say N.
  407. config SCHED_OMIT_FRAME_POINTER
  408. def_bool y
  409. prompt "Single-depth WCHAN output"
  410. depends on X86
  411. ---help---
  412. Calculate simpler /proc/<PID>/wchan values. If this option
  413. is disabled then wchan values will recurse back to the
  414. caller function. This provides more accurate wchan values,
  415. at the expense of slightly more scheduling overhead.
  416. If in doubt, say "Y".
  417. menuconfig PARAVIRT_GUEST
  418. bool "Paravirtualized guest support"
  419. ---help---
  420. Say Y here to get to see options related to running Linux under
  421. various hypervisors. This option alone does not add any kernel code.
  422. If you say N, all options in this submenu will be skipped and disabled.
  423. if PARAVIRT_GUEST
  424. source "arch/x86/xen/Kconfig"
  425. config KVM_CLOCK
  426. bool "KVM paravirtualized clock"
  427. select PARAVIRT
  428. select PARAVIRT_CLOCK
  429. ---help---
  430. Turning on this option will allow you to run a paravirtualized clock
  431. when running over the KVM hypervisor. Instead of relying on a PIT
  432. (or probably other) emulation by the underlying device model, the host
  433. provides the guest with timing infrastructure such as time of day, and
  434. system time
  435. config KVM_GUEST
  436. bool "KVM Guest support"
  437. select PARAVIRT
  438. ---help---
  439. This option enables various optimizations for running under the KVM
  440. hypervisor.
  441. source "arch/x86/lguest/Kconfig"
  442. config PARAVIRT
  443. bool "Enable paravirtualization code"
  444. ---help---
  445. This changes the kernel so it can modify itself when it is run
  446. under a hypervisor, potentially improving performance significantly
  447. over full virtualization. However, when run without a hypervisor
  448. the kernel is theoretically slower and slightly larger.
  449. config PARAVIRT_SPINLOCKS
  450. bool "Paravirtualization layer for spinlocks"
  451. depends on PARAVIRT && SMP && EXPERIMENTAL
  452. ---help---
  453. Paravirtualized spinlocks allow a pvops backend to replace the
  454. spinlock implementation with something virtualization-friendly
  455. (for example, block the virtual CPU rather than spinning).
  456. Unfortunately the downside is an up to 5% performance hit on
  457. native kernels, with various workloads.
  458. If you are unsure how to answer this question, answer N.
  459. config PARAVIRT_CLOCK
  460. bool
  461. endif
  462. config PARAVIRT_DEBUG
  463. bool "paravirt-ops debugging"
  464. depends on PARAVIRT && DEBUG_KERNEL
  465. ---help---
  466. Enable to debug paravirt_ops internals. Specifically, BUG if
  467. a paravirt_op is missing when it is called.
  468. config NO_BOOTMEM
  469. def_bool y
  470. config MEMTEST
  471. bool "Memtest"
  472. ---help---
  473. This option adds a kernel parameter 'memtest', which allows memtest
  474. to be set.
  475. memtest=0, mean disabled; -- default
  476. memtest=1, mean do 1 test pattern;
  477. ...
  478. memtest=4, mean do 4 test patterns.
  479. If you are unsure how to answer this question, answer N.
  480. config X86_SUMMIT_NUMA
  481. def_bool y
  482. depends on X86_32 && NUMA && X86_32_NON_STANDARD
  483. config X86_CYCLONE_TIMER
  484. def_bool y
  485. depends on X86_32_NON_STANDARD
  486. source "arch/x86/Kconfig.cpu"
  487. config HPET_TIMER
  488. def_bool X86_64
  489. prompt "HPET Timer Support" if X86_32
  490. ---help---
  491. Use the IA-PC HPET (High Precision Event Timer) to manage
  492. time in preference to the PIT and RTC, if a HPET is
  493. present.
  494. HPET is the next generation timer replacing legacy 8254s.
  495. The HPET provides a stable time base on SMP
  496. systems, unlike the TSC, but it is more expensive to access,
  497. as it is off-chip. You can find the HPET spec at
  498. <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
  499. You can safely choose Y here. However, HPET will only be
  500. activated if the platform and the BIOS support this feature.
  501. Otherwise the 8254 will be used for timing services.
  502. Choose N to continue using the legacy 8254 timer.
  503. config HPET_EMULATE_RTC
  504. def_bool y
  505. depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
  506. config APB_TIMER
  507. def_bool y if MRST
  508. prompt "Langwell APB Timer Support" if X86_MRST
  509. help
  510. APB timer is the replacement for 8254, HPET on X86 MID platforms.
  511. The APBT provides a stable time base on SMP
  512. systems, unlike the TSC, but it is more expensive to access,
  513. as it is off-chip. APB timers are always running regardless of CPU
  514. C states, they are used as per CPU clockevent device when possible.
  515. # Mark as expert because too many people got it wrong.
  516. # The code disables itself when not needed.
  517. config DMI
  518. default y
  519. bool "Enable DMI scanning" if EXPERT
  520. ---help---
  521. Enabled scanning of DMI to identify machine quirks. Say Y
  522. here unless you have verified that your setup is not
  523. affected by entries in the DMI blacklist. Required by PNP
  524. BIOS code.
  525. config GART_IOMMU
  526. bool "GART IOMMU support" if EXPERT
  527. default y
  528. select SWIOTLB
  529. depends on X86_64 && PCI && AMD_NB
  530. ---help---
  531. Support for full DMA access of devices with 32bit memory access only
  532. on systems with more than 3GB. This is usually needed for USB,
  533. sound, many IDE/SATA chipsets and some other devices.
  534. Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
  535. based hardware IOMMU and a software bounce buffer based IOMMU used
  536. on Intel systems and as fallback.
  537. The code is only active when needed (enough memory and limited
  538. device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
  539. too.
  540. config CALGARY_IOMMU
  541. bool "IBM Calgary IOMMU support"
  542. select SWIOTLB
  543. depends on X86_64 && PCI && EXPERIMENTAL
  544. ---help---
  545. Support for hardware IOMMUs in IBM's xSeries x366 and x460
  546. systems. Needed to run systems with more than 3GB of memory
  547. properly with 32-bit PCI devices that do not support DAC
  548. (Double Address Cycle). Calgary also supports bus level
  549. isolation, where all DMAs pass through the IOMMU. This
  550. prevents them from going anywhere except their intended
  551. destination. This catches hard-to-find kernel bugs and
  552. mis-behaving drivers and devices that do not use the DMA-API
  553. properly to set up their DMA buffers. The IOMMU can be
  554. turned off at boot time with the iommu=off parameter.
  555. Normally the kernel will make the right choice by itself.
  556. If unsure, say Y.
  557. config CALGARY_IOMMU_ENABLED_BY_DEFAULT
  558. def_bool y
  559. prompt "Should Calgary be enabled by default?"
  560. depends on CALGARY_IOMMU
  561. ---help---
  562. Should Calgary be enabled by default? if you choose 'y', Calgary
  563. will be used (if it exists). If you choose 'n', Calgary will not be
  564. used even if it exists. If you choose 'n' and would like to use
  565. Calgary anyway, pass 'iommu=calgary' on the kernel command line.
  566. If unsure, say Y.
  567. config AMD_IOMMU
  568. bool "AMD IOMMU support"
  569. select SWIOTLB
  570. select PCI_MSI
  571. depends on X86_64 && PCI && ACPI
  572. ---help---
  573. With this option you can enable support for AMD IOMMU hardware in
  574. your system. An IOMMU is a hardware component which provides
  575. remapping of DMA memory accesses from devices. With an AMD IOMMU you
  576. can isolate the the DMA memory of different devices and protect the
  577. system from misbehaving device drivers or hardware.
  578. You can find out if your system has an AMD IOMMU if you look into
  579. your BIOS for an option to enable it or if you have an IVRS ACPI
  580. table.
  581. config AMD_IOMMU_STATS
  582. bool "Export AMD IOMMU statistics to debugfs"
  583. depends on AMD_IOMMU
  584. select DEBUG_FS
  585. ---help---
  586. This option enables code in the AMD IOMMU driver to collect various
  587. statistics about whats happening in the driver and exports that
  588. information to userspace via debugfs.
  589. If unsure, say N.
  590. # need this always selected by IOMMU for the VIA workaround
  591. config SWIOTLB
  592. def_bool y if X86_64
  593. ---help---
  594. Support for software bounce buffers used on x86-64 systems
  595. which don't have a hardware IOMMU (e.g. the current generation
  596. of Intel's x86-64 CPUs). Using this PCI devices which can only
  597. access 32-bits of memory can be used on systems with more than
  598. 3 GB of memory. If unsure, say Y.
  599. config IOMMU_HELPER
  600. def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
  601. config IOMMU_API
  602. def_bool (AMD_IOMMU || DMAR)
  603. config MAXSMP
  604. bool "Enable Maximum number of SMP Processors and NUMA Nodes"
  605. depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
  606. select CPUMASK_OFFSTACK
  607. ---help---
  608. Enable maximum number of CPUS and NUMA Nodes for this architecture.
  609. If unsure, say N.
  610. config NR_CPUS
  611. int "Maximum number of CPUs" if SMP && !MAXSMP
  612. range 2 8 if SMP && X86_32 && !X86_BIGSMP
  613. range 2 512 if SMP && !MAXSMP
  614. default "1" if !SMP
  615. default "4096" if MAXSMP
  616. default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
  617. default "8" if SMP
  618. ---help---
  619. This allows you to specify the maximum number of CPUs which this
  620. kernel will support. The maximum supported value is 512 and the
  621. minimum value which makes sense is 2.
  622. This is purely to save memory - each supported CPU adds
  623. approximately eight kilobytes to the kernel image.
  624. config SCHED_SMT
  625. bool "SMT (Hyperthreading) scheduler support"
  626. depends on X86_HT
  627. ---help---
  628. SMT scheduler support improves the CPU scheduler's decision making
  629. when dealing with Intel Pentium 4 chips with HyperThreading at a
  630. cost of slightly increased overhead in some places. If unsure say
  631. N here.
  632. config SCHED_MC
  633. def_bool y
  634. prompt "Multi-core scheduler support"
  635. depends on X86_HT
  636. ---help---
  637. Multi-core scheduler support improves the CPU scheduler's decision
  638. making when dealing with multi-core CPU chips at a cost of slightly
  639. increased overhead in some places. If unsure say N here.
  640. config IRQ_TIME_ACCOUNTING
  641. bool "Fine granularity task level IRQ time accounting"
  642. default n
  643. ---help---
  644. Select this option to enable fine granularity task irq time
  645. accounting. This is done by reading a timestamp on each
  646. transitions between softirq and hardirq state, so there can be a
  647. small performance impact.
  648. If in doubt, say N here.
  649. source "kernel/Kconfig.preempt"
  650. config X86_UP_APIC
  651. bool "Local APIC support on uniprocessors"
  652. depends on X86_32 && !SMP && !X86_32_NON_STANDARD
  653. ---help---
  654. A local APIC (Advanced Programmable Interrupt Controller) is an
  655. integrated interrupt controller in the CPU. If you have a single-CPU
  656. system which has a processor with a local APIC, you can say Y here to
  657. enable and use it. If you say Y here even though your machine doesn't
  658. have a local APIC, then the kernel will still run with no slowdown at
  659. all. The local APIC supports CPU-generated self-interrupts (timer,
  660. performance counters), and the NMI watchdog which detects hard
  661. lockups.
  662. config X86_UP_IOAPIC
  663. bool "IO-APIC support on uniprocessors"
  664. depends on X86_UP_APIC
  665. ---help---
  666. An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
  667. SMP-capable replacement for PC-style interrupt controllers. Most
  668. SMP systems and many recent uniprocessor systems have one.
  669. If you have a single-CPU system with an IO-APIC, you can say Y here
  670. to use it. If you say Y here even though your machine doesn't have
  671. an IO-APIC, then the kernel will still run with no slowdown at all.
  672. config X86_LOCAL_APIC
  673. def_bool y
  674. depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
  675. config X86_IO_APIC
  676. def_bool y
  677. depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
  678. config X86_VISWS_APIC
  679. def_bool y
  680. depends on X86_32 && X86_VISWS
  681. config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
  682. bool "Reroute for broken boot IRQs"
  683. depends on X86_IO_APIC
  684. ---help---
  685. This option enables a workaround that fixes a source of
  686. spurious interrupts. This is recommended when threaded
  687. interrupt handling is used on systems where the generation of
  688. superfluous "boot interrupts" cannot be disabled.
  689. Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
  690. entry in the chipset's IO-APIC is masked (as, e.g. the RT
  691. kernel does during interrupt handling). On chipsets where this
  692. boot IRQ generation cannot be disabled, this workaround keeps
  693. the original IRQ line masked so that only the equivalent "boot
  694. IRQ" is delivered to the CPUs. The workaround also tells the
  695. kernel to set up the IRQ handler on the boot IRQ line. In this
  696. way only one interrupt is delivered to the kernel. Otherwise
  697. the spurious second interrupt may cause the kernel to bring
  698. down (vital) interrupt lines.
  699. Only affects "broken" chipsets. Interrupt sharing may be
  700. increased on these systems.
  701. config X86_MCE
  702. bool "Machine Check / overheating reporting"
  703. ---help---
  704. Machine Check support allows the processor to notify the
  705. kernel if it detects a problem (e.g. overheating, data corruption).
  706. The action the kernel takes depends on the severity of the problem,
  707. ranging from warning messages to halting the machine.
  708. config X86_MCE_INTEL
  709. def_bool y
  710. prompt "Intel MCE features"
  711. depends on X86_MCE && X86_LOCAL_APIC
  712. ---help---
  713. Additional support for intel specific MCE features such as
  714. the thermal monitor.
  715. config X86_MCE_AMD
  716. def_bool y
  717. prompt "AMD MCE features"
  718. depends on X86_MCE && X86_LOCAL_APIC
  719. ---help---
  720. Additional support for AMD specific MCE features such as
  721. the DRAM Error Threshold.
  722. config X86_ANCIENT_MCE
  723. bool "Support for old Pentium 5 / WinChip machine checks"
  724. depends on X86_32 && X86_MCE
  725. ---help---
  726. Include support for machine check handling on old Pentium 5 or WinChip
  727. systems. These typically need to be enabled explicitely on the command
  728. line.
  729. config X86_MCE_THRESHOLD
  730. depends on X86_MCE_AMD || X86_MCE_INTEL
  731. def_bool y
  732. config X86_MCE_INJECT
  733. depends on X86_MCE
  734. tristate "Machine check injector support"
  735. ---help---
  736. Provide support for injecting machine checks for testing purposes.
  737. If you don't know what a machine check is and you don't do kernel
  738. QA it is safe to say n.
  739. config X86_THERMAL_VECTOR
  740. def_bool y
  741. depends on X86_MCE_INTEL
  742. config VM86
  743. bool "Enable VM86 support" if EXPERT
  744. default y
  745. depends on X86_32
  746. ---help---
  747. This option is required by programs like DOSEMU to run 16-bit legacy
  748. code on X86 processors. It also may be needed by software like
  749. XFree86 to initialize some video cards via BIOS. Disabling this
  750. option saves about 6k.
  751. config TOSHIBA
  752. tristate "Toshiba Laptop support"
  753. depends on X86_32
  754. ---help---
  755. This adds a driver to safely access the System Management Mode of
  756. the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
  757. not work on models with a Phoenix BIOS. The System Management Mode
  758. is used to set the BIOS and power saving options on Toshiba portables.
  759. For information on utilities to make use of this driver see the
  760. Toshiba Linux utilities web site at:
  761. <http://www.buzzard.org.uk/toshiba/>.
  762. Say Y if you intend to run this kernel on a Toshiba portable.
  763. Say N otherwise.
  764. config I8K
  765. tristate "Dell laptop support"
  766. ---help---
  767. This adds a driver to safely access the System Management Mode
  768. of the CPU on the Dell Inspiron 8000. The System Management Mode
  769. is used to read cpu temperature and cooling fan status and to
  770. control the fans on the I8K portables.
  771. This driver has been tested only on the Inspiron 8000 but it may
  772. also work with other Dell laptops. You can force loading on other
  773. models by passing the parameter `force=1' to the module. Use at
  774. your own risk.
  775. For information on utilities to make use of this driver see the
  776. I8K Linux utilities web site at:
  777. <http://people.debian.org/~dz/i8k/>
  778. Say Y if you intend to run this kernel on a Dell Inspiron 8000.
  779. Say N otherwise.
  780. config X86_REBOOTFIXUPS
  781. bool "Enable X86 board specific fixups for reboot"
  782. depends on X86_32
  783. ---help---
  784. This enables chipset and/or board specific fixups to be done
  785. in order to get reboot to work correctly. This is only needed on
  786. some combinations of hardware and BIOS. The symptom, for which
  787. this config is intended, is when reboot ends with a stalled/hung
  788. system.
  789. Currently, the only fixup is for the Geode machines using
  790. CS5530A and CS5536 chipsets and the RDC R-321x SoC.
  791. Say Y if you want to enable the fixup. Currently, it's safe to
  792. enable this option even if you don't need it.
  793. Say N otherwise.
  794. config MICROCODE
  795. tristate "/dev/cpu/microcode - microcode support"
  796. select FW_LOADER
  797. ---help---
  798. If you say Y here, you will be able to update the microcode on
  799. certain Intel and AMD processors. The Intel support is for the
  800. IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
  801. Pentium 4, Xeon etc. The AMD support is for family 0x10 and
  802. 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
  803. You will obviously need the actual microcode binary data itself
  804. which is not shipped with the Linux kernel.
  805. This option selects the general module only, you need to select
  806. at least one vendor specific module as well.
  807. To compile this driver as a module, choose M here: the
  808. module will be called microcode.
  809. config MICROCODE_INTEL
  810. bool "Intel microcode patch loading support"
  811. depends on MICROCODE
  812. default MICROCODE
  813. select FW_LOADER
  814. ---help---
  815. This options enables microcode patch loading support for Intel
  816. processors.
  817. For latest news and information on obtaining all the required
  818. Intel ingredients for this driver, check:
  819. <http://www.urbanmyth.org/microcode/>.
  820. config MICROCODE_AMD
  821. bool "AMD microcode patch loading support"
  822. depends on MICROCODE
  823. select FW_LOADER
  824. ---help---
  825. If you select this option, microcode patch loading support for AMD
  826. processors will be enabled.
  827. config MICROCODE_OLD_INTERFACE
  828. def_bool y
  829. depends on MICROCODE
  830. config X86_MSR
  831. tristate "/dev/cpu/*/msr - Model-specific register support"
  832. ---help---
  833. This device gives privileged processes access to the x86
  834. Model-Specific Registers (MSRs). It is a character device with
  835. major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
  836. MSR accesses are directed to a specific CPU on multi-processor
  837. systems.
  838. config X86_CPUID
  839. tristate "/dev/cpu/*/cpuid - CPU information support"
  840. ---help---
  841. This device gives processes access to the x86 CPUID instruction to
  842. be executed on a specific processor. It is a character device
  843. with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
  844. /dev/cpu/31/cpuid.
  845. choice
  846. prompt "High Memory Support"
  847. default HIGHMEM64G if X86_NUMAQ
  848. default HIGHMEM4G
  849. depends on X86_32
  850. config NOHIGHMEM
  851. bool "off"
  852. depends on !X86_NUMAQ
  853. ---help---
  854. Linux can use up to 64 Gigabytes of physical memory on x86 systems.
  855. However, the address space of 32-bit x86 processors is only 4
  856. Gigabytes large. That means that, if you have a large amount of
  857. physical memory, not all of it can be "permanently mapped" by the
  858. kernel. The physical memory that's not permanently mapped is called
  859. "high memory".
  860. If you are compiling a kernel which will never run on a machine with
  861. more than 1 Gigabyte total physical RAM, answer "off" here (default
  862. choice and suitable for most users). This will result in a "3GB/1GB"
  863. split: 3GB are mapped so that each process sees a 3GB virtual memory
  864. space and the remaining part of the 4GB virtual memory space is used
  865. by the kernel to permanently map as much physical memory as
  866. possible.
  867. If the machine has between 1 and 4 Gigabytes physical RAM, then
  868. answer "4GB" here.
  869. If more than 4 Gigabytes is used then answer "64GB" here. This
  870. selection turns Intel PAE (Physical Address Extension) mode on.
  871. PAE implements 3-level paging on IA32 processors. PAE is fully
  872. supported by Linux, PAE mode is implemented on all recent Intel
  873. processors (Pentium Pro and better). NOTE: If you say "64GB" here,
  874. then the kernel will not boot on CPUs that don't support PAE!
  875. The actual amount of total physical memory will either be
  876. auto detected or can be forced by using a kernel command line option
  877. such as "mem=256M". (Try "man bootparam" or see the documentation of
  878. your boot loader (lilo or loadlin) about how to pass options to the
  879. kernel at boot time.)
  880. If unsure, say "off".
  881. config HIGHMEM4G
  882. bool "4GB"
  883. depends on !X86_NUMAQ
  884. ---help---
  885. Select this if you have a 32-bit processor and between 1 and 4
  886. gigabytes of physical RAM.
  887. config HIGHMEM64G
  888. bool "64GB"
  889. depends on !M386 && !M486
  890. select X86_PAE
  891. ---help---
  892. Select this if you have a 32-bit processor and more than 4
  893. gigabytes of physical RAM.
  894. endchoice
  895. choice
  896. depends on EXPERIMENTAL
  897. prompt "Memory split" if EXPERT
  898. default VMSPLIT_3G
  899. depends on X86_32
  900. ---help---
  901. Select the desired split between kernel and user memory.
  902. If the address range available to the kernel is less than the
  903. physical memory installed, the remaining memory will be available
  904. as "high memory". Accessing high memory is a little more costly
  905. than low memory, as it needs to be mapped into the kernel first.
  906. Note that increasing the kernel address space limits the range
  907. available to user programs, making the address space there
  908. tighter. Selecting anything other than the default 3G/1G split
  909. will also likely make your kernel incompatible with binary-only
  910. kernel modules.
  911. If you are not absolutely sure what you are doing, leave this
  912. option alone!
  913. config VMSPLIT_3G
  914. bool "3G/1G user/kernel split"
  915. config VMSPLIT_3G_OPT
  916. depends on !X86_PAE
  917. bool "3G/1G user/kernel split (for full 1G low memory)"
  918. config VMSPLIT_2G
  919. bool "2G/2G user/kernel split"
  920. config VMSPLIT_2G_OPT
  921. depends on !X86_PAE
  922. bool "2G/2G user/kernel split (for full 2G low memory)"
  923. config VMSPLIT_1G
  924. bool "1G/3G user/kernel split"
  925. endchoice
  926. config PAGE_OFFSET
  927. hex
  928. default 0xB0000000 if VMSPLIT_3G_OPT
  929. default 0x80000000 if VMSPLIT_2G
  930. default 0x78000000 if VMSPLIT_2G_OPT
  931. default 0x40000000 if VMSPLIT_1G
  932. default 0xC0000000
  933. depends on X86_32
  934. config HIGHMEM
  935. def_bool y
  936. depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
  937. config X86_PAE
  938. bool "PAE (Physical Address Extension) Support"
  939. depends on X86_32 && !HIGHMEM4G
  940. ---help---
  941. PAE is required for NX support, and furthermore enables
  942. larger swapspace support for non-overcommit purposes. It
  943. has the cost of more pagetable lookup overhead, and also
  944. consumes more pagetable space per process.
  945. config ARCH_PHYS_ADDR_T_64BIT
  946. def_bool X86_64 || X86_PAE
  947. config ARCH_DMA_ADDR_T_64BIT
  948. def_bool X86_64 || HIGHMEM64G
  949. config DIRECT_GBPAGES
  950. bool "Enable 1GB pages for kernel pagetables" if EXPERT
  951. default y
  952. depends on X86_64
  953. ---help---
  954. Allow the kernel linear mapping to use 1GB pages on CPUs that
  955. support it. This can improve the kernel's performance a tiny bit by
  956. reducing TLB pressure. If in doubt, say "Y".
  957. # Common NUMA Features
  958. config NUMA
  959. bool "Numa Memory Allocation and Scheduler Support"
  960. depends on SMP
  961. depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
  962. default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
  963. ---help---
  964. Enable NUMA (Non Uniform Memory Access) support.
  965. The kernel will try to allocate memory used by a CPU on the
  966. local memory controller of the CPU and add some more
  967. NUMA awareness to the kernel.
  968. For 64-bit this is recommended if the system is Intel Core i7
  969. (or later), AMD Opteron, or EM64T NUMA.
  970. For 32-bit this is only needed on (rare) 32-bit-only platforms
  971. that support NUMA topologies, such as NUMAQ / Summit, or if you
  972. boot a 32-bit kernel on a 64-bit NUMA platform.
  973. Otherwise, you should say N.
  974. comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
  975. depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
  976. config AMD_NUMA
  977. def_bool y
  978. prompt "Old style AMD Opteron NUMA detection"
  979. depends on X86_64 && NUMA && PCI
  980. ---help---
  981. Enable AMD NUMA node topology detection. You should say Y here if
  982. you have a multi processor AMD system. This uses an old method to
  983. read the NUMA configuration directly from the builtin Northbridge
  984. of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
  985. which also takes priority if both are compiled in.
  986. config X86_64_ACPI_NUMA
  987. def_bool y
  988. prompt "ACPI NUMA detection"
  989. depends on X86_64 && NUMA && ACPI && PCI
  990. select ACPI_NUMA
  991. ---help---
  992. Enable ACPI SRAT based node topology detection.
  993. # Some NUMA nodes have memory ranges that span
  994. # other nodes. Even though a pfn is valid and
  995. # between a node's start and end pfns, it may not
  996. # reside on that node. See memmap_init_zone()
  997. # for details.
  998. config NODES_SPAN_OTHER_NODES
  999. def_bool y
  1000. depends on X86_64_ACPI_NUMA
  1001. config NUMA_EMU
  1002. bool "NUMA emulation"
  1003. depends on X86_64 && NUMA
  1004. ---help---
  1005. Enable NUMA emulation. A flat machine will be split
  1006. into virtual nodes when booted with "numa=fake=N", where N is the
  1007. number of nodes. This is only useful for debugging.
  1008. config NODES_SHIFT
  1009. int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
  1010. range 1 10
  1011. default "10" if MAXSMP
  1012. default "6" if X86_64
  1013. default "4" if X86_NUMAQ
  1014. default "3"
  1015. depends on NEED_MULTIPLE_NODES
  1016. ---help---
  1017. Specify the maximum number of NUMA Nodes available on the target
  1018. system. Increases memory reserved to accommodate various tables.
  1019. config HAVE_ARCH_BOOTMEM
  1020. def_bool y
  1021. depends on X86_32 && NUMA
  1022. config ARCH_HAVE_MEMORY_PRESENT
  1023. def_bool y
  1024. depends on X86_32 && DISCONTIGMEM
  1025. config NEED_NODE_MEMMAP_SIZE
  1026. def_bool y
  1027. depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
  1028. config HAVE_ARCH_ALLOC_REMAP
  1029. def_bool y
  1030. depends on X86_32 && NUMA
  1031. config ARCH_FLATMEM_ENABLE
  1032. def_bool y
  1033. depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
  1034. config ARCH_DISCONTIGMEM_ENABLE
  1035. def_bool y
  1036. depends on NUMA && X86_32
  1037. config ARCH_DISCONTIGMEM_DEFAULT
  1038. def_bool y
  1039. depends on NUMA && X86_32
  1040. config ARCH_PROC_KCORE_TEXT
  1041. def_bool y
  1042. depends on X86_64 && PROC_KCORE
  1043. config ARCH_SPARSEMEM_DEFAULT
  1044. def_bool y
  1045. depends on X86_64
  1046. config ARCH_SPARSEMEM_ENABLE
  1047. def_bool y
  1048. depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
  1049. select SPARSEMEM_STATIC if X86_32
  1050. select SPARSEMEM_VMEMMAP_ENABLE if X86_64
  1051. config ARCH_SELECT_MEMORY_MODEL
  1052. def_bool y
  1053. depends on ARCH_SPARSEMEM_ENABLE
  1054. config ARCH_MEMORY_PROBE
  1055. def_bool X86_64
  1056. depends on MEMORY_HOTPLUG
  1057. config ILLEGAL_POINTER_VALUE
  1058. hex
  1059. default 0 if X86_32
  1060. default 0xdead000000000000 if X86_64
  1061. source "mm/Kconfig"
  1062. config HIGHPTE
  1063. bool "Allocate 3rd-level pagetables from highmem"
  1064. depends on HIGHMEM
  1065. ---help---
  1066. The VM uses one page table entry for each page of physical memory.
  1067. For systems with a lot of RAM, this can be wasteful of precious
  1068. low memory. Setting this option will put user-space page table
  1069. entries in high memory.
  1070. config X86_CHECK_BIOS_CORRUPTION
  1071. bool "Check for low memory corruption"
  1072. ---help---
  1073. Periodically check for memory corruption in low memory, which
  1074. is suspected to be caused by BIOS. Even when enabled in the
  1075. configuration, it is disabled at runtime. Enable it by
  1076. setting "memory_corruption_check=1" on the kernel command
  1077. line. By default it scans the low 64k of memory every 60
  1078. seconds; see the memory_corruption_check_size and
  1079. memory_corruption_check_period parameters in
  1080. Documentation/kernel-parameters.txt to adjust this.
  1081. When enabled with the default parameters, this option has
  1082. almost no overhead, as it reserves a relatively small amount
  1083. of memory and scans it infrequently. It both detects corruption
  1084. and prevents it from affecting the running system.
  1085. It is, however, intended as a diagnostic tool; if repeatable
  1086. BIOS-originated corruption always affects the same memory,
  1087. you can use memmap= to prevent the kernel from using that
  1088. memory.
  1089. config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
  1090. bool "Set the default setting of memory_corruption_check"
  1091. depends on X86_CHECK_BIOS_CORRUPTION
  1092. default y
  1093. ---help---
  1094. Set whether the default state of memory_corruption_check is
  1095. on or off.
  1096. config X86_RESERVE_LOW
  1097. int "Amount of low memory, in kilobytes, to reserve for the BIOS"
  1098. default 64
  1099. range 4 640
  1100. ---help---
  1101. Specify the amount of low memory to reserve for the BIOS.
  1102. The first page contains BIOS data structures that the kernel
  1103. must not use, so that page must always be reserved.
  1104. By default we reserve the first 64K of physical RAM, as a
  1105. number of BIOSes are known to corrupt that memory range
  1106. during events such as suspend/resume or monitor cable
  1107. insertion, so it must not be used by the kernel.
  1108. You can set this to 4 if you are absolutely sure that you
  1109. trust the BIOS to get all its memory reservations and usages
  1110. right. If you know your BIOS have problems beyond the
  1111. default 64K area, you can set this to 640 to avoid using the
  1112. entire low memory range.
  1113. If you have doubts about the BIOS (e.g. suspend/resume does
  1114. not work or there's kernel crashes after certain hardware
  1115. hotplug events) then you might want to enable
  1116. X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
  1117. typical corruption patterns.
  1118. Leave this to the default value of 64 if you are unsure.
  1119. config MATH_EMULATION
  1120. bool
  1121. prompt "Math emulation" if X86_32
  1122. ---help---
  1123. Linux can emulate a math coprocessor (used for floating point
  1124. operations) if you don't have one. 486DX and Pentium processors have
  1125. a math coprocessor built in, 486SX and 386 do not, unless you added
  1126. a 487DX or 387, respectively. (The messages during boot time can
  1127. give you some hints here ["man dmesg"].) Everyone needs either a
  1128. coprocessor or this emulation.
  1129. If you don't have a math coprocessor, you need to say Y here; if you
  1130. say Y here even though you have a coprocessor, the coprocessor will
  1131. be used nevertheless. (This behavior can be changed with the kernel
  1132. command line option "no387", which comes handy if your coprocessor
  1133. is broken. Try "man bootparam" or see the documentation of your boot
  1134. loader (lilo or loadlin) about how to pass options to the kernel at
  1135. boot time.) This means that it is a good idea to say Y here if you
  1136. intend to use this kernel on different machines.
  1137. More information about the internals of the Linux math coprocessor
  1138. emulation can be found in <file:arch/x86/math-emu/README>.
  1139. If you are not sure, say Y; apart from resulting in a 66 KB bigger
  1140. kernel, it won't hurt.
  1141. config MTRR
  1142. def_bool y
  1143. prompt "MTRR (Memory Type Range Register) support" if EXPERT
  1144. ---help---
  1145. On Intel P6 family processors (Pentium Pro, Pentium II and later)
  1146. the Memory Type Range Registers (MTRRs) may be used to control
  1147. processor access to memory ranges. This is most useful if you have
  1148. a video (VGA) card on a PCI or AGP bus. Enabling write-combining
  1149. allows bus write transfers to be combined into a larger transfer
  1150. before bursting over the PCI/AGP bus. This can increase performance
  1151. of image write operations 2.5 times or more. Saying Y here creates a
  1152. /proc/mtrr file which may be used to manipulate your processor's
  1153. MTRRs. Typically the X server should use this.
  1154. This code has a reasonably generic interface so that similar
  1155. control registers on other processors can be easily supported
  1156. as well:
  1157. The Cyrix 6x86, 6x86MX and M II processors have Address Range
  1158. Registers (ARRs) which provide a similar functionality to MTRRs. For
  1159. these, the ARRs are used to emulate the MTRRs.
  1160. The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
  1161. MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
  1162. write-combining. All of these processors are supported by this code
  1163. and it makes sense to say Y here if you have one of them.
  1164. Saying Y here also fixes a problem with buggy SMP BIOSes which only
  1165. set the MTRRs for the boot CPU and not for the secondary CPUs. This
  1166. can lead to all sorts of problems, so it's good to say Y here.
  1167. You can safely say Y even if your machine doesn't have MTRRs, you'll
  1168. just add about 9 KB to your kernel.
  1169. See <file:Documentation/x86/mtrr.txt> for more information.
  1170. config MTRR_SANITIZER
  1171. def_bool y
  1172. prompt "MTRR cleanup support"
  1173. depends on MTRR
  1174. ---help---
  1175. Convert MTRR layout from continuous to discrete, so X drivers can
  1176. add writeback entries.
  1177. Can be disabled with disable_mtrr_cleanup on the kernel command line.
  1178. The largest mtrr entry size for a continuous block can be set with
  1179. mtrr_chunk_size.
  1180. If unsure, say Y.
  1181. config MTRR_SANITIZER_ENABLE_DEFAULT
  1182. int "MTRR cleanup enable value (0-1)"
  1183. range 0 1
  1184. default "0"
  1185. depends on MTRR_SANITIZER
  1186. ---help---
  1187. Enable mtrr cleanup default value
  1188. config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
  1189. int "MTRR cleanup spare reg num (0-7)"
  1190. range 0 7
  1191. default "1"
  1192. depends on MTRR_SANITIZER
  1193. ---help---
  1194. mtrr cleanup spare entries default, it can be changed via
  1195. mtrr_spare_reg_nr=N on the kernel command line.
  1196. config X86_PAT
  1197. def_bool y
  1198. prompt "x86 PAT support" if EXPERT
  1199. depends on MTRR
  1200. ---help---
  1201. Use PAT attributes to setup page level cache control.
  1202. PATs are the modern equivalents of MTRRs and are much more
  1203. flexible than MTRRs.
  1204. Say N here if you see bootup problems (boot crash, boot hang,
  1205. spontaneous reboots) or a non-working video driver.
  1206. If unsure, say Y.
  1207. config ARCH_USES_PG_UNCACHED
  1208. def_bool y
  1209. depends on X86_PAT
  1210. config EFI
  1211. bool "EFI runtime service support"
  1212. depends on ACPI
  1213. ---help---
  1214. This enables the kernel to use EFI runtime services that are
  1215. available (such as the EFI variable services).
  1216. This option is only useful on systems that have EFI firmware.
  1217. In addition, you should use the latest ELILO loader available
  1218. at <http://elilo.sourceforge.net> in order to take advantage
  1219. of EFI runtime services. However, even with this option, the
  1220. resultant kernel should continue to boot on existing non-EFI
  1221. platforms.
  1222. config SECCOMP
  1223. def_bool y
  1224. prompt "Enable seccomp to safely compute untrusted bytecode"
  1225. ---help---
  1226. This kernel feature is useful for number crunching applications
  1227. that may need to compute untrusted bytecode during their
  1228. execution. By using pipes or other transports made available to
  1229. the process as file descriptors supporting the read/write
  1230. syscalls, it's possible to isolate those applications in
  1231. their own address space using seccomp. Once seccomp is
  1232. enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
  1233. and the task is only allowed to execute a few safe syscalls
  1234. defined by each seccomp mode.
  1235. If unsure, say Y. Only embedded should say N here.
  1236. config CC_STACKPROTECTOR
  1237. bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
  1238. ---help---
  1239. This option turns on the -fstack-protector GCC feature. This
  1240. feature puts, at the beginning of functions, a canary value on
  1241. the stack just before the return address, and validates
  1242. the value just before actually returning. Stack based buffer
  1243. overflows (that need to overwrite this return address) now also
  1244. overwrite the canary, which gets detected and the attack is then
  1245. neutralized via a kernel panic.
  1246. This feature requires gcc version 4.2 or above, or a distribution
  1247. gcc with the feature backported. Older versions are automatically
  1248. detected and for those versions, this configuration option is
  1249. ignored. (and a warning is printed during bootup)
  1250. source kernel/Kconfig.hz
  1251. config KEXEC
  1252. bool "kexec system call"
  1253. ---help---
  1254. kexec is a system call that implements the ability to shutdown your
  1255. current kernel, and to start another kernel. It is like a reboot
  1256. but it is independent of the system firmware. And like a reboot
  1257. you can start any kernel with it, not just Linux.
  1258. The name comes from the similarity to the exec system call.
  1259. It is an ongoing process to be certain the hardware in a machine
  1260. is properly shutdown, so do not be surprised if this code does not
  1261. initially work for you. It may help to enable device hotplugging
  1262. support. As of this writing the exact hardware interface is
  1263. strongly in flux, so no good recommendation can be made.
  1264. config CRASH_DUMP
  1265. bool "kernel crash dumps"
  1266. depends on X86_64 || (X86_32 && HIGHMEM)
  1267. ---help---
  1268. Generate crash dump after being started by kexec.
  1269. This should be normally only set in special crash dump kernels
  1270. which are loaded in the main kernel with kexec-tools into
  1271. a specially reserved region and then later executed after
  1272. a crash by kdump/kexec. The crash dump kernel must be compiled
  1273. to a memory address not used by the main kernel or BIOS using
  1274. PHYSICAL_START, or it must be built as a relocatable image
  1275. (CONFIG_RELOCATABLE=y).
  1276. For more details see Documentation/kdump/kdump.txt
  1277. config KEXEC_JUMP
  1278. bool "kexec jump (EXPERIMENTAL)"
  1279. depends on EXPERIMENTAL
  1280. depends on KEXEC && HIBERNATION
  1281. ---help---
  1282. Jump between original kernel and kexeced kernel and invoke
  1283. code in physical address mode via KEXEC
  1284. config PHYSICAL_START
  1285. hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
  1286. default "0x1000000"
  1287. ---help---
  1288. This gives the physical address where the kernel is loaded.
  1289. If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
  1290. bzImage will decompress itself to above physical address and
  1291. run from there. Otherwise, bzImage will run from the address where
  1292. it has been loaded by the boot loader and will ignore above physical
  1293. address.
  1294. In normal kdump cases one does not have to set/change this option
  1295. as now bzImage can be compiled as a completely relocatable image
  1296. (CONFIG_RELOCATABLE=y) and be used to load and run from a different
  1297. address. This option is mainly useful for the folks who don't want
  1298. to use a bzImage for capturing the crash dump and want to use a
  1299. vmlinux instead. vmlinux is not relocatable hence a kernel needs
  1300. to be specifically compiled to run from a specific memory area
  1301. (normally a reserved region) and this option comes handy.
  1302. So if you are using bzImage for capturing the crash dump,
  1303. leave the value here unchanged to 0x1000000 and set
  1304. CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
  1305. for capturing the crash dump change this value to start of
  1306. the reserved region. In other words, it can be set based on
  1307. the "X" value as specified in the "crashkernel=YM@XM"
  1308. command line boot parameter passed to the panic-ed
  1309. kernel. Please take a look at Documentation/kdump/kdump.txt
  1310. for more details about crash dumps.
  1311. Usage of bzImage for capturing the crash dump is recommended as
  1312. one does not have to build two kernels. Same kernel can be used
  1313. as production kernel and capture kernel. Above option should have
  1314. gone away after relocatable bzImage support is introduced. But it
  1315. is present because there are users out there who continue to use
  1316. vmlinux for dump capture. This option should go away down the
  1317. line.
  1318. Don't change this unless you know what you are doing.
  1319. config RELOCATABLE
  1320. bool "Build a relocatable kernel"
  1321. default y
  1322. ---help---
  1323. This builds a kernel image that retains relocation information
  1324. so it can be loaded someplace besides the default 1MB.
  1325. The relocations tend to make the kernel binary about 10% larger,
  1326. but are discarded at runtime.
  1327. One use is for the kexec on panic case where the recovery kernel
  1328. must live at a different physical address than the primary
  1329. kernel.
  1330. Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
  1331. it has been loaded at and the compile time physical address
  1332. (CONFIG_PHYSICAL_START) is ignored.
  1333. # Relocation on x86-32 needs some additional build support
  1334. config X86_NEED_RELOCS
  1335. def_bool y
  1336. depends on X86_32 && RELOCATABLE
  1337. config PHYSICAL_ALIGN
  1338. hex "Alignment value to which kernel should be aligned" if X86_32
  1339. default "0x1000000"
  1340. range 0x2000 0x1000000
  1341. ---help---
  1342. This value puts the alignment restrictions on physical address
  1343. where kernel is loaded and run from. Kernel is compiled for an
  1344. address which meets above alignment restriction.
  1345. If bootloader loads the kernel at a non-aligned address and
  1346. CONFIG_RELOCATABLE is set, kernel will move itself to nearest
  1347. address aligned to above value and run from there.
  1348. If bootloader loads the kernel at a non-aligned address and
  1349. CONFIG_RELOCATABLE is not set, kernel will ignore the run time
  1350. load address and decompress itself to the address it has been
  1351. compiled for and run from there. The address for which kernel is
  1352. compiled already meets above alignment restrictions. Hence the
  1353. end result is that kernel runs from a physical address meeting
  1354. above alignment restrictions.
  1355. Don't change this unless you know what you are doing.
  1356. config HOTPLUG_CPU
  1357. bool "Support for hot-pluggable CPUs"
  1358. depends on SMP && HOTPLUG
  1359. ---help---
  1360. Say Y here to allow turning CPUs off and on. CPUs can be
  1361. controlled through /sys/devices/system/cpu.
  1362. ( Note: power management support will enable this option
  1363. automatically on SMP systems. )
  1364. Say N if you want to disable CPU hotplug.
  1365. config COMPAT_VDSO
  1366. def_bool y
  1367. prompt "Compat VDSO support"
  1368. depends on X86_32 || IA32_EMULATION
  1369. ---help---
  1370. Map the 32-bit VDSO to the predictable old-style address too.
  1371. Say N here if you are running a sufficiently recent glibc
  1372. version (2.3.3 or later), to remove the high-mapped
  1373. VDSO mapping and to exclusively use the randomized VDSO.
  1374. If unsure, say Y.
  1375. config CMDLINE_BOOL
  1376. bool "Built-in kernel command line"
  1377. ---help---
  1378. Allow for specifying boot arguments to the kernel at
  1379. build time. On some systems (e.g. embedded ones), it is
  1380. necessary or convenient to provide some or all of the
  1381. kernel boot arguments with the kernel itself (that is,
  1382. to not rely on the boot loader to provide them.)
  1383. To compile command line arguments into the kernel,
  1384. set this option to 'Y', then fill in the
  1385. the boot arguments in CONFIG_CMDLINE.
  1386. Systems with fully functional boot loaders (i.e. non-embedded)
  1387. should leave this option set to 'N'.
  1388. config CMDLINE
  1389. string "Built-in kernel command string"
  1390. depends on CMDLINE_BOOL
  1391. default ""
  1392. ---help---
  1393. Enter arguments here that should be compiled into the kernel
  1394. image and used at boot time. If the boot loader provides a
  1395. command line at boot time, it is appended to this string to
  1396. form the full kernel command line, when the system boots.
  1397. However, you can use the CONFIG_CMDLINE_OVERRIDE option to
  1398. change this behavior.
  1399. In most cases, the command line (whether built-in or provided
  1400. by the boot loader) should specify the device for the root
  1401. file system.
  1402. config CMDLINE_OVERRIDE
  1403. bool "Built-in command line overrides boot loader arguments"
  1404. depends on CMDLINE_BOOL
  1405. ---help---
  1406. Set this option to 'Y' to have the kernel ignore the boot loader
  1407. command line, and use ONLY the built-in command line.
  1408. This is used to work around broken boot loaders. This should
  1409. be set to 'N' under normal conditions.
  1410. endmenu
  1411. config ARCH_ENABLE_MEMORY_HOTPLUG
  1412. def_bool y
  1413. depends on X86_64 || (X86_32 && HIGHMEM)
  1414. config ARCH_ENABLE_MEMORY_HOTREMOVE
  1415. def_bool y
  1416. depends on MEMORY_HOTPLUG
  1417. config HAVE_ARCH_EARLY_PFN_TO_NID
  1418. def_bool X86_64
  1419. depends on NUMA
  1420. config USE_PERCPU_NUMA_NODE_ID
  1421. def_bool y
  1422. depends on NUMA
  1423. menu "Power management and ACPI options"
  1424. config ARCH_HIBERNATION_HEADER
  1425. def_bool y
  1426. depends on X86_64 && HIBERNATION
  1427. source "kernel/power/Kconfig"
  1428. source "drivers/acpi/Kconfig"
  1429. source "drivers/sfi/Kconfig"
  1430. config X86_APM_BOOT
  1431. def_bool y
  1432. depends on APM || APM_MODULE
  1433. menuconfig APM
  1434. tristate "APM (Advanced Power Management) BIOS support"
  1435. depends on X86_32 && PM_SLEEP
  1436. ---help---
  1437. APM is a BIOS specification for saving power using several different
  1438. techniques. This is mostly useful for battery powered laptops with
  1439. APM compliant BIOSes. If you say Y here, the system time will be
  1440. reset after a RESUME operation, the /proc/apm device will provide
  1441. battery status information, and user-space programs will receive
  1442. notification of APM "events" (e.g. battery status change).
  1443. If you select "Y" here, you can disable actual use of the APM
  1444. BIOS by passing the "apm=off" option to the kernel at boot time.
  1445. Note that the APM support is almost completely disabled for
  1446. machines with more than one CPU.
  1447. In order to use APM, you will need supporting software. For location
  1448. and more information, read <file:Documentation/power/pm.txt> and the
  1449. Battery Powered Linux mini-HOWTO, available from
  1450. <http://www.tldp.org/docs.html#howto>.
  1451. This driver does not spin down disk drives (see the hdparm(8)
  1452. manpage ("man 8 hdparm") for that), and it doesn't turn off
  1453. VESA-compliant "green" monitors.
  1454. This driver does not support the TI 4000M TravelMate and the ACER
  1455. 486/DX4/75 because they don't have compliant BIOSes. Many "green"
  1456. desktop machines also don't have compliant BIOSes, and this driver
  1457. may cause those machines to panic during the boot phase.
  1458. Generally, if you don't have a battery in your machine, there isn't
  1459. much point in using this driver and you should say N. If you get
  1460. random kernel OOPSes or reboots that don't seem to be related to
  1461. anything, try disabling/enabling this option (or disabling/enabling
  1462. APM in your BIOS).
  1463. Some other things you should try when experiencing seemingly random,
  1464. "weird" problems:
  1465. 1) make sure that you have enough swap space and that it is
  1466. enabled.
  1467. 2) pass the "no-hlt" option to the kernel
  1468. 3) switch on floating point emulation in the kernel and pass
  1469. the "no387" option to the kernel
  1470. 4) pass the "floppy=nodma" option to the kernel
  1471. 5) pass the "mem=4M" option to the kernel (thereby disabling
  1472. all but the first 4 MB of RAM)
  1473. 6) make sure that the CPU is not over clocked.
  1474. 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
  1475. 8) disable the cache from your BIOS settings
  1476. 9) install a fan for the video card or exchange video RAM
  1477. 10) install a better fan for the CPU
  1478. 11) exchange RAM chips
  1479. 12) exchange the motherboard.
  1480. To compile this driver as a module, choose M here: the
  1481. module will be called apm.
  1482. if APM
  1483. config APM_IGNORE_USER_SUSPEND
  1484. bool "Ignore USER SUSPEND"
  1485. ---help---
  1486. This option will ignore USER SUSPEND requests. On machines with a
  1487. compliant APM BIOS, you want to say N. However, on the NEC Versa M
  1488. series notebooks, it is necessary to say Y because of a BIOS bug.
  1489. config APM_DO_ENABLE
  1490. bool "Enable PM at boot time"
  1491. ---help---
  1492. Enable APM features at boot time. From page 36 of the APM BIOS
  1493. specification: "When disabled, the APM BIOS does not automatically
  1494. power manage devices, enter the Standby State, enter the Suspend
  1495. State, or take power saving steps in response to CPU Idle calls."
  1496. This driver will make CPU Idle calls when Linux is idle (unless this
  1497. feature is turned off -- see "Do CPU IDLE calls", below). This
  1498. should always save battery power, but more complicated APM features
  1499. will be dependent on your BIOS implementation. You may need to turn
  1500. this option off if your computer hangs at boot time when using APM
  1501. support, or if it beeps continuously instead of suspending. Turn
  1502. this off if you have a NEC UltraLite Versa 33/C or a Toshiba
  1503. T400CDT. This is off by default since most machines do fine without
  1504. this feature.
  1505. config APM_CPU_IDLE
  1506. bool "Make CPU Idle calls when idle"
  1507. ---help---
  1508. Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
  1509. On some machines, this can activate improved power savings, such as
  1510. a slowed CPU clock rate, when the machine is idle. These idle calls
  1511. are made after the idle loop has run for some length of time (e.g.,
  1512. 333 mS). On some machines, this will cause a hang at boot time or
  1513. whenever the CPU becomes idle. (On machines with more than one CPU,
  1514. this option does nothing.)
  1515. config APM_DISPLAY_BLANK
  1516. bool "Enable console blanking using APM"
  1517. ---help---
  1518. Enable console blanking using the APM. Some laptops can use this to
  1519. turn off the LCD backlight when the screen blanker of the Linux
  1520. virtual console blanks the screen. Note that this is only used by
  1521. the virtual console screen blanker, and won't turn off the backlight
  1522. when using the X Window system. This also doesn't have anything to
  1523. do with your VESA-compliant power-saving monitor. Further, this
  1524. option doesn't work for all laptops -- it might not turn off your
  1525. backlight at all, or it might print a lot of errors to the console,
  1526. especially if you are using gpm.
  1527. config APM_ALLOW_INTS
  1528. bool "Allow interrupts during APM BIOS calls"
  1529. ---help---
  1530. Normally we disable external interrupts while we are making calls to
  1531. the APM BIOS as a measure to lessen the effects of a badly behaving
  1532. BIOS implementation. The BIOS should reenable interrupts if it
  1533. needs to. Unfortunately, some BIOSes do not -- especially those in
  1534. many of the newer IBM Thinkpads. If you experience hangs when you
  1535. suspend, try setting this to Y. Otherwise, say N.
  1536. endif # APM
  1537. source "arch/x86/kernel/cpu/cpufreq/Kconfig"
  1538. source "drivers/cpuidle/Kconfig"
  1539. source "drivers/idle/Kconfig"
  1540. endmenu
  1541. menu "Bus options (PCI etc.)"
  1542. config PCI
  1543. bool "PCI support"
  1544. default y
  1545. select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
  1546. ---help---
  1547. Find out whether you have a PCI motherboard. PCI is the name of a
  1548. bus system, i.e. the way the CPU talks to the other stuff inside
  1549. your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
  1550. VESA. If you have PCI, say Y, otherwise N.
  1551. choice
  1552. prompt "PCI access mode"
  1553. depends on X86_32 && PCI
  1554. default PCI_GOANY
  1555. ---help---
  1556. On PCI systems, the BIOS can be used to detect the PCI devices and
  1557. determine their configuration. However, some old PCI motherboards
  1558. have BIOS bugs and may crash if this is done. Also, some embedded
  1559. PCI-based systems don't have any BIOS at all. Linux can also try to
  1560. detect the PCI hardware directly without using the BIOS.
  1561. With this option, you can specify how Linux should detect the
  1562. PCI devices. If you choose "BIOS", the BIOS will be used,
  1563. if you choose "Direct", the BIOS won't be used, and if you
  1564. choose "MMConfig", then PCI Express MMCONFIG will be used.
  1565. If you choose "Any", the kernel will try MMCONFIG, then the
  1566. direct access method and falls back to the BIOS if that doesn't
  1567. work. If unsure, go with the default, which is "Any".
  1568. config PCI_GOBIOS
  1569. bool "BIOS"
  1570. config PCI_GOMMCONFIG
  1571. bool "MMConfig"
  1572. config PCI_GODIRECT
  1573. bool "Direct"
  1574. config PCI_GOOLPC
  1575. bool "OLPC XO-1"
  1576. depends on OLPC
  1577. config PCI_GOANY
  1578. bool "Any"
  1579. endchoice
  1580. config PCI_BIOS
  1581. def_bool y
  1582. depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
  1583. # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
  1584. config PCI_DIRECT
  1585. def_bool y
  1586. depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
  1587. config PCI_MMCONFIG
  1588. def_bool y
  1589. depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
  1590. config PCI_OLPC
  1591. def_bool y
  1592. depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
  1593. config PCI_XEN
  1594. def_bool y
  1595. depends on PCI && XEN
  1596. select SWIOTLB_XEN
  1597. config PCI_DOMAINS
  1598. def_bool y
  1599. depends on PCI
  1600. config PCI_MMCONFIG
  1601. bool "Support mmconfig PCI config space access"
  1602. depends on X86_64 && PCI && ACPI
  1603. config PCI_CNB20LE_QUIRK
  1604. bool "Read CNB20LE Host Bridge Windows" if EXPERT
  1605. default n
  1606. depends on PCI && EXPERIMENTAL
  1607. help
  1608. Read the PCI windows out of the CNB20LE host bridge. This allows
  1609. PCI hotplug to work on systems with the CNB20LE chipset which do
  1610. not have ACPI.
  1611. There's no public spec for this chipset, and this functionality
  1612. is known to be incomplete.
  1613. You should say N unless you know you need this.
  1614. config DMAR
  1615. bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
  1616. depends on PCI_MSI && ACPI && EXPERIMENTAL
  1617. help
  1618. DMA remapping (DMAR) devices support enables independent address
  1619. translations for Direct Memory Access (DMA) from devices.
  1620. These DMA remapping devices are reported via ACPI tables
  1621. and include PCI device scope covered by these DMA
  1622. remapping devices.
  1623. config DMAR_DEFAULT_ON
  1624. def_bool y
  1625. prompt "Enable DMA Remapping Devices by default"
  1626. depends on DMAR
  1627. help
  1628. Selecting this option will enable a DMAR device at boot time if
  1629. one is found. If this option is not selected, DMAR support can
  1630. be enabled by passing intel_iommu=on to the kernel. It is
  1631. recommended you say N here while the DMAR code remains
  1632. experimental.
  1633. config DMAR_BROKEN_GFX_WA
  1634. bool "Workaround broken graphics drivers (going away soon)"
  1635. depends on DMAR && BROKEN
  1636. ---help---
  1637. Current Graphics drivers tend to use physical address
  1638. for DMA and avoid using DMA APIs. Setting this config
  1639. option permits the IOMMU driver to set a unity map for
  1640. all the OS-visible memory. Hence the driver can continue
  1641. to use physical addresses for DMA, at least until this
  1642. option is removed in the 2.6.32 kernel.
  1643. config DMAR_FLOPPY_WA
  1644. def_bool y
  1645. depends on DMAR
  1646. ---help---
  1647. Floppy disk drivers are known to bypass DMA API calls
  1648. thereby failing to work when IOMMU is enabled. This
  1649. workaround will setup a 1:1 mapping for the first
  1650. 16MiB to make floppy (an ISA device) work.
  1651. config INTR_REMAP
  1652. bool "Support for Interrupt Remapping (EXPERIMENTAL)"
  1653. depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
  1654. ---help---
  1655. Supports Interrupt remapping for IO-APIC and MSI devices.
  1656. To use x2apic mode in the CPU's which support x2APIC enhancements or
  1657. to support platforms with CPU's having > 8 bit APIC ID, say Y.
  1658. source "drivers/pci/pcie/Kconfig"
  1659. source "drivers/pci/Kconfig"
  1660. # x86_64 have no ISA slots, but do have ISA-style DMA.
  1661. config ISA_DMA_API
  1662. def_bool y
  1663. if X86_32
  1664. config ISA
  1665. bool "ISA support"
  1666. ---help---
  1667. Find out whether you have ISA slots on your motherboard. ISA is the
  1668. name of a bus system, i.e. the way the CPU talks to the other stuff
  1669. inside your box. Other bus systems are PCI, EISA, MicroChannel
  1670. (MCA) or VESA. ISA is an older system, now being displaced by PCI;
  1671. newer boards don't support it. If you have ISA, say Y, otherwise N.
  1672. config EISA
  1673. bool "EISA support"
  1674. depends on ISA
  1675. ---help---
  1676. The Extended Industry Standard Architecture (EISA) bus was
  1677. developed as an open alternative to the IBM MicroChannel bus.
  1678. The EISA bus provided some of the features of the IBM MicroChannel
  1679. bus while maintaining backward compatibility with cards made for
  1680. the older ISA bus. The EISA bus saw limited use between 1988 and
  1681. 1995 when it was made obsolete by the PCI bus.
  1682. Say Y here if you are building a kernel for an EISA-based machine.
  1683. Otherwise, say N.
  1684. source "drivers/eisa/Kconfig"
  1685. config MCA
  1686. bool "MCA support"
  1687. ---help---
  1688. MicroChannel Architecture is found in some IBM PS/2 machines and
  1689. laptops. It is a bus system similar to PCI or ISA. See
  1690. <file:Documentation/mca.txt> (and especially the web page given
  1691. there) before attempting to build an MCA bus kernel.
  1692. source "drivers/mca/Kconfig"
  1693. config SCx200
  1694. tristate "NatSemi SCx200 support"
  1695. ---help---
  1696. This provides basic support for National Semiconductor's
  1697. (now AMD's) Geode processors. The driver probes for the
  1698. PCI-IDs of several on-chip devices, so its a good dependency
  1699. for other scx200_* drivers.
  1700. If compiled as a module, the driver is named scx200.
  1701. config SCx200HR_TIMER
  1702. tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
  1703. depends on SCx200
  1704. default y
  1705. ---help---
  1706. This driver provides a clocksource built upon the on-chip
  1707. 27MHz high-resolution timer. Its also a workaround for
  1708. NSC Geode SC-1100's buggy TSC, which loses time when the
  1709. processor goes idle (as is done by the scheduler). The
  1710. other workaround is idle=poll boot option.
  1711. config OLPC
  1712. bool "One Laptop Per Child support"
  1713. depends on !X86_PAE
  1714. select GPIOLIB
  1715. select OF
  1716. select OF_PROMTREE if PROC_DEVICETREE
  1717. ---help---
  1718. Add support for detecting the unique features of the OLPC
  1719. XO hardware.
  1720. config OLPC_XO1
  1721. tristate "OLPC XO-1 support"
  1722. depends on OLPC && MFD_CS5535
  1723. ---help---
  1724. Add support for non-essential features of the OLPC XO-1 laptop.
  1725. endif # X86_32
  1726. config AMD_NB
  1727. def_bool y
  1728. depends on CPU_SUP_AMD && PCI
  1729. source "drivers/pcmcia/Kconfig"
  1730. source "drivers/pci/hotplug/Kconfig"
  1731. endmenu
  1732. menu "Executable file formats / Emulations"
  1733. source "fs/Kconfig.binfmt"
  1734. config IA32_EMULATION
  1735. bool "IA32 Emulation"
  1736. depends on X86_64
  1737. select COMPAT_BINFMT_ELF
  1738. ---help---
  1739. Include code to run 32-bit programs under a 64-bit kernel. You should
  1740. likely turn this on, unless you're 100% sure that you don't have any
  1741. 32-bit programs left.
  1742. config IA32_AOUT
  1743. tristate "IA32 a.out support"
  1744. depends on IA32_EMULATION
  1745. ---help---
  1746. Support old a.out binaries in the 32bit emulation.
  1747. config COMPAT
  1748. def_bool y
  1749. depends on IA32_EMULATION
  1750. config COMPAT_FOR_U64_ALIGNMENT
  1751. def_bool COMPAT
  1752. depends on X86_64
  1753. config SYSVIPC_COMPAT
  1754. def_bool y
  1755. depends on COMPAT && SYSVIPC
  1756. endmenu
  1757. config HAVE_ATOMIC_IOMAP
  1758. def_bool y
  1759. depends on X86_32
  1760. config HAVE_TEXT_POKE_SMP
  1761. bool
  1762. select STOP_MACHINE if SMP
  1763. source "net/Kconfig"
  1764. source "drivers/Kconfig"
  1765. source "drivers/firmware/Kconfig"
  1766. source "fs/Kconfig"
  1767. source "arch/x86/Kconfig.debug"
  1768. source "security/Kconfig"
  1769. source "crypto/Kconfig"
  1770. source "arch/x86/kvm/Kconfig"
  1771. source "lib/Kconfig"