Kconfig 57 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_UNSTABLE_SCHED_CLOCK
  19. select HAVE_IDE
  20. select HAVE_OPROFILE
  21. select HAVE_IOREMAP_PROT
  22. select HAVE_KPROBES
  23. select ARCH_WANT_OPTIONAL_GPIOLIB
  24. select HAVE_KRETPROBES
  25. select HAVE_DYNAMIC_FTRACE
  26. select HAVE_FTRACE
  27. select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64)
  28. select HAVE_ARCH_KGDB if !X86_VOYAGER
  29. select HAVE_GENERIC_DMA_COHERENT if X86_32
  30. select HAVE_EFFICIENT_UNALIGNED_ACCESS
  31. config ARCH_DEFCONFIG
  32. string
  33. default "arch/x86/configs/i386_defconfig" if X86_32
  34. default "arch/x86/configs/x86_64_defconfig" if X86_64
  35. config GENERIC_LOCKBREAK
  36. def_bool n
  37. config GENERIC_TIME
  38. def_bool y
  39. config GENERIC_CMOS_UPDATE
  40. def_bool y
  41. config CLOCKSOURCE_WATCHDOG
  42. def_bool y
  43. config GENERIC_CLOCKEVENTS
  44. def_bool y
  45. config GENERIC_CLOCKEVENTS_BROADCAST
  46. def_bool y
  47. depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
  48. config LOCKDEP_SUPPORT
  49. def_bool y
  50. config STACKTRACE_SUPPORT
  51. def_bool y
  52. config HAVE_LATENCYTOP_SUPPORT
  53. def_bool y
  54. config FAST_CMPXCHG_LOCAL
  55. bool
  56. default y
  57. config MMU
  58. def_bool y
  59. config ZONE_DMA
  60. def_bool y
  61. config SBUS
  62. bool
  63. config GENERIC_ISA_DMA
  64. def_bool y
  65. config GENERIC_IOMAP
  66. def_bool y
  67. config GENERIC_BUG
  68. def_bool y
  69. depends on BUG
  70. config GENERIC_HWEIGHT
  71. def_bool y
  72. config GENERIC_GPIO
  73. def_bool n
  74. config ARCH_MAY_HAVE_PC_FDC
  75. def_bool y
  76. config RWSEM_GENERIC_SPINLOCK
  77. def_bool !X86_XADD
  78. config RWSEM_XCHGADD_ALGORITHM
  79. def_bool X86_XADD
  80. config ARCH_HAS_ILOG2_U32
  81. def_bool n
  82. config ARCH_HAS_ILOG2_U64
  83. def_bool n
  84. config ARCH_HAS_CPU_IDLE_WAIT
  85. def_bool y
  86. config GENERIC_CALIBRATE_DELAY
  87. def_bool y
  88. config GENERIC_TIME_VSYSCALL
  89. bool
  90. default X86_64
  91. config ARCH_HAS_CPU_RELAX
  92. def_bool y
  93. config ARCH_HAS_CACHE_LINE_SIZE
  94. def_bool y
  95. config HAVE_SETUP_PER_CPU_AREA
  96. def_bool X86_64_SMP || (X86_SMP && !X86_VOYAGER)
  97. config HAVE_CPUMASK_OF_CPU_MAP
  98. def_bool X86_64_SMP
  99. config ARCH_HIBERNATION_POSSIBLE
  100. def_bool y
  101. depends on !SMP || !X86_VOYAGER
  102. config ARCH_SUSPEND_POSSIBLE
  103. def_bool y
  104. depends on !X86_VOYAGER
  105. config ZONE_DMA32
  106. bool
  107. default X86_64
  108. config ARCH_POPULATES_NODE_MAP
  109. def_bool y
  110. config AUDIT_ARCH
  111. bool
  112. default X86_64
  113. config ARCH_SUPPORTS_OPTIMIZED_INLINING
  114. def_bool y
  115. # Use the generic interrupt handling code in kernel/irq/:
  116. config GENERIC_HARDIRQS
  117. bool
  118. default y
  119. config GENERIC_IRQ_PROBE
  120. bool
  121. default y
  122. config GENERIC_PENDING_IRQ
  123. bool
  124. depends on GENERIC_HARDIRQS && SMP
  125. default y
  126. config X86_SMP
  127. bool
  128. depends on SMP && ((X86_32 && !X86_VOYAGER) || X86_64)
  129. select USE_GENERIC_SMP_HELPERS
  130. default y
  131. config X86_32_SMP
  132. def_bool y
  133. depends on X86_32 && SMP
  134. config X86_64_SMP
  135. def_bool y
  136. depends on X86_64 && SMP
  137. config X86_HT
  138. bool
  139. depends on SMP
  140. depends on (X86_32 && !X86_VOYAGER) || X86_64
  141. default y
  142. config X86_BIOS_REBOOT
  143. bool
  144. depends on !X86_VOYAGER
  145. default y
  146. config X86_TRAMPOLINE
  147. bool
  148. depends on X86_SMP || (X86_VOYAGER && SMP) || (64BIT && ACPI_SLEEP)
  149. default y
  150. config KTIME_SCALAR
  151. def_bool X86_32
  152. source "init/Kconfig"
  153. menu "Processor type and features"
  154. source "kernel/time/Kconfig"
  155. config SMP
  156. bool "Symmetric multi-processing support"
  157. ---help---
  158. This enables support for systems with more than one CPU. If you have
  159. a system with only one CPU, like most personal computers, say N. If
  160. you have a system with more than one CPU, say Y.
  161. If you say N here, the kernel will run on single and multiprocessor
  162. machines, but will use only one CPU of a multiprocessor machine. If
  163. you say Y here, the kernel will run on many, but not all,
  164. singleprocessor machines. On a singleprocessor machine, the kernel
  165. will run faster if you say N here.
  166. Note that if you say Y here and choose architecture "586" or
  167. "Pentium" under "Processor family", the kernel will not work on 486
  168. architectures. Similarly, multiprocessor kernels for the "PPro"
  169. architecture may not work on all Pentium based boards.
  170. People using multiprocessor machines who say Y here should also say
  171. Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
  172. Management" code will be disabled if you say Y here.
  173. See also <file:Documentation/i386/IO-APIC.txt>,
  174. <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
  175. <http://www.tldp.org/docs.html#howto>.
  176. If you don't know what to do here, say N.
  177. config X86_FIND_SMP_CONFIG
  178. def_bool y
  179. depends on X86_MPPARSE || X86_VOYAGER
  180. if ACPI
  181. config X86_MPPARSE
  182. def_bool y
  183. bool "Enable MPS table"
  184. depends on X86_LOCAL_APIC
  185. help
  186. For old smp systems that do not have proper acpi support. Newer systems
  187. (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
  188. endif
  189. if !ACPI
  190. config X86_MPPARSE
  191. def_bool y
  192. depends on X86_LOCAL_APIC
  193. endif
  194. choice
  195. prompt "Subarchitecture Type"
  196. default X86_PC
  197. config X86_PC
  198. bool "PC-compatible"
  199. help
  200. Choose this option if your computer is a standard PC or compatible.
  201. config X86_ELAN
  202. bool "AMD Elan"
  203. depends on X86_32
  204. help
  205. Select this for an AMD Elan processor.
  206. Do not use this option for K6/Athlon/Opteron processors!
  207. If unsure, choose "PC-compatible" instead.
  208. config X86_VOYAGER
  209. bool "Voyager (NCR)"
  210. depends on X86_32 && (SMP || BROKEN) && !PCI
  211. help
  212. Voyager is an MCA-based 32-way capable SMP architecture proprietary
  213. to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
  214. *** WARNING ***
  215. If you do not specifically know you have a Voyager based machine,
  216. say N here, otherwise the kernel you build will not be bootable.
  217. config X86_GENERICARCH
  218. bool "Generic architecture"
  219. depends on X86_32
  220. help
  221. This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
  222. subarchitectures. It is intended for a generic binary kernel.
  223. if you select them all, kernel will probe it one by one. and will
  224. fallback to default.
  225. if X86_GENERICARCH
  226. config X86_NUMAQ
  227. bool "NUMAQ (IBM/Sequent)"
  228. depends on SMP && X86_32 && PCI && X86_MPPARSE
  229. select NUMA
  230. help
  231. This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
  232. NUMA multiquad box. This changes the way that processors are
  233. bootstrapped, and uses Clustered Logical APIC addressing mode instead
  234. of Flat Logical. You will need a new lynxer.elf file to flash your
  235. firmware with - send email to <Martin.Bligh@us.ibm.com>.
  236. config X86_SUMMIT
  237. bool "Summit/EXA (IBM x440)"
  238. depends on X86_32 && SMP
  239. help
  240. This option is needed for IBM systems that use the Summit/EXA chipset.
  241. In particular, it is needed for the x440.
  242. config X86_ES7000
  243. bool "Support for Unisys ES7000 IA32 series"
  244. depends on X86_32 && SMP
  245. help
  246. Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
  247. supposed to run on an IA32-based Unisys ES7000 system.
  248. config X86_BIGSMP
  249. bool "Support for big SMP systems with more than 8 CPUs"
  250. depends on X86_32 && SMP
  251. help
  252. This option is needed for the systems that have more than 8 CPUs
  253. and if the system is not of any sub-arch type above.
  254. endif
  255. config X86_VSMP
  256. bool "Support for ScaleMP vSMP"
  257. select PARAVIRT
  258. depends on X86_64 && PCI
  259. help
  260. Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
  261. supposed to run on these EM64T-based machines. Only choose this option
  262. if you have one of these machines.
  263. endchoice
  264. config X86_VISWS
  265. bool "SGI 320/540 (Visual Workstation)"
  266. depends on X86_32 && PCI && !X86_VOYAGER && X86_MPPARSE && PCI_GODIRECT
  267. help
  268. The SGI Visual Workstation series is an IA32-based workstation
  269. based on SGI systems chips with some legacy PC hardware attached.
  270. Say Y here to create a kernel to run on the SGI 320 or 540.
  271. A kernel compiled for the Visual Workstation will run on general
  272. PCs as well. See <file:Documentation/sgi-visws.txt> for details.
  273. config X86_RDC321X
  274. bool "RDC R-321x SoC"
  275. depends on X86_32
  276. select M486
  277. select X86_REBOOTFIXUPS
  278. help
  279. This option is needed for RDC R-321x system-on-chip, also known
  280. as R-8610-(G).
  281. If you don't have one of these chips, you should say N here.
  282. config SCHED_NO_NO_OMIT_FRAME_POINTER
  283. def_bool y
  284. prompt "Single-depth WCHAN output"
  285. depends on X86_32
  286. help
  287. Calculate simpler /proc/<PID>/wchan values. If this option
  288. is disabled then wchan values will recurse back to the
  289. caller function. This provides more accurate wchan values,
  290. at the expense of slightly more scheduling overhead.
  291. If in doubt, say "Y".
  292. menuconfig PARAVIRT_GUEST
  293. bool "Paravirtualized guest support"
  294. help
  295. Say Y here to get to see options related to running Linux under
  296. various hypervisors. This option alone does not add any kernel code.
  297. If you say N, all options in this submenu will be skipped and disabled.
  298. if PARAVIRT_GUEST
  299. source "arch/x86/xen/Kconfig"
  300. config VMI
  301. bool "VMI Guest support"
  302. select PARAVIRT
  303. depends on X86_32
  304. depends on !X86_VOYAGER
  305. help
  306. VMI provides a paravirtualized interface to the VMware ESX server
  307. (it could be used by other hypervisors in theory too, but is not
  308. at the moment), by linking the kernel to a GPL-ed ROM module
  309. provided by the hypervisor.
  310. config KVM_CLOCK
  311. bool "KVM paravirtualized clock"
  312. select PARAVIRT
  313. select PARAVIRT_CLOCK
  314. depends on !X86_VOYAGER
  315. help
  316. Turning on this option will allow you to run a paravirtualized clock
  317. when running over the KVM hypervisor. Instead of relying on a PIT
  318. (or probably other) emulation by the underlying device model, the host
  319. provides the guest with timing infrastructure such as time of day, and
  320. system time
  321. config KVM_GUEST
  322. bool "KVM Guest support"
  323. select PARAVIRT
  324. depends on !X86_VOYAGER
  325. help
  326. This option enables various optimizations for running under the KVM
  327. hypervisor.
  328. source "arch/x86/lguest/Kconfig"
  329. config PARAVIRT
  330. bool "Enable paravirtualization code"
  331. depends on !X86_VOYAGER
  332. help
  333. This changes the kernel so it can modify itself when it is run
  334. under a hypervisor, potentially improving performance significantly
  335. over full virtualization. However, when run without a hypervisor
  336. the kernel is theoretically slower and slightly larger.
  337. config PARAVIRT_CLOCK
  338. bool
  339. default n
  340. endif
  341. config PARAVIRT_DEBUG
  342. bool "paravirt-ops debugging"
  343. depends on PARAVIRT && DEBUG_KERNEL
  344. help
  345. Enable to debug paravirt_ops internals. Specifically, BUG if
  346. a paravirt_op is missing when it is called.
  347. config MEMTEST
  348. bool "Memtest"
  349. help
  350. This option adds a kernel parameter 'memtest', which allows memtest
  351. to be set.
  352. memtest=0, mean disabled; -- default
  353. memtest=1, mean do 1 test pattern;
  354. ...
  355. memtest=4, mean do 4 test patterns.
  356. If you are unsure how to answer this question, answer N.
  357. config X86_SUMMIT_NUMA
  358. def_bool y
  359. depends on X86_32 && NUMA && X86_GENERICARCH
  360. config X86_CYCLONE_TIMER
  361. def_bool y
  362. depends on X86_GENERICARCH
  363. config ES7000_CLUSTERED_APIC
  364. def_bool y
  365. depends on SMP && X86_ES7000 && MPENTIUMIII
  366. source "arch/x86/Kconfig.cpu"
  367. config HPET_TIMER
  368. def_bool X86_64
  369. prompt "HPET Timer Support" if X86_32
  370. help
  371. Use the IA-PC HPET (High Precision Event Timer) to manage
  372. time in preference to the PIT and RTC, if a HPET is
  373. present.
  374. HPET is the next generation timer replacing legacy 8254s.
  375. The HPET provides a stable time base on SMP
  376. systems, unlike the TSC, but it is more expensive to access,
  377. as it is off-chip. You can find the HPET spec at
  378. <http://www.intel.com/hardwaredesign/hpetspec.htm>.
  379. You can safely choose Y here. However, HPET will only be
  380. activated if the platform and the BIOS support this feature.
  381. Otherwise the 8254 will be used for timing services.
  382. Choose N to continue using the legacy 8254 timer.
  383. config HPET_EMULATE_RTC
  384. def_bool y
  385. depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
  386. # Mark as embedded because too many people got it wrong.
  387. # The code disables itself when not needed.
  388. config DMI
  389. default y
  390. bool "Enable DMI scanning" if EMBEDDED
  391. help
  392. Enabled scanning of DMI to identify machine quirks. Say Y
  393. here unless you have verified that your setup is not
  394. affected by entries in the DMI blacklist. Required by PNP
  395. BIOS code.
  396. config GART_IOMMU
  397. bool "GART IOMMU support" if EMBEDDED
  398. default y
  399. select SWIOTLB
  400. select AGP
  401. depends on X86_64 && PCI
  402. help
  403. Support for full DMA access of devices with 32bit memory access only
  404. on systems with more than 3GB. This is usually needed for USB,
  405. sound, many IDE/SATA chipsets and some other devices.
  406. Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
  407. based hardware IOMMU and a software bounce buffer based IOMMU used
  408. on Intel systems and as fallback.
  409. The code is only active when needed (enough memory and limited
  410. device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
  411. too.
  412. config CALGARY_IOMMU
  413. bool "IBM Calgary IOMMU support"
  414. select SWIOTLB
  415. depends on X86_64 && PCI && EXPERIMENTAL
  416. help
  417. Support for hardware IOMMUs in IBM's xSeries x366 and x460
  418. systems. Needed to run systems with more than 3GB of memory
  419. properly with 32-bit PCI devices that do not support DAC
  420. (Double Address Cycle). Calgary also supports bus level
  421. isolation, where all DMAs pass through the IOMMU. This
  422. prevents them from going anywhere except their intended
  423. destination. This catches hard-to-find kernel bugs and
  424. mis-behaving drivers and devices that do not use the DMA-API
  425. properly to set up their DMA buffers. The IOMMU can be
  426. turned off at boot time with the iommu=off parameter.
  427. Normally the kernel will make the right choice by itself.
  428. If unsure, say Y.
  429. config CALGARY_IOMMU_ENABLED_BY_DEFAULT
  430. def_bool y
  431. prompt "Should Calgary be enabled by default?"
  432. depends on CALGARY_IOMMU
  433. help
  434. Should Calgary be enabled by default? if you choose 'y', Calgary
  435. will be used (if it exists). If you choose 'n', Calgary will not be
  436. used even if it exists. If you choose 'n' and would like to use
  437. Calgary anyway, pass 'iommu=calgary' on the kernel command line.
  438. If unsure, say Y.
  439. config AMD_IOMMU
  440. bool "AMD IOMMU support"
  441. select SWIOTLB
  442. depends on X86_64 && PCI && ACPI
  443. help
  444. With this option you can enable support for AMD IOMMU hardware in
  445. your system. An IOMMU is a hardware component which provides
  446. remapping of DMA memory accesses from devices. With an AMD IOMMU you
  447. can isolate the the DMA memory of different devices and protect the
  448. system from misbehaving device drivers or hardware.
  449. You can find out if your system has an AMD IOMMU if you look into
  450. your BIOS for an option to enable it or if you have an IVRS ACPI
  451. table.
  452. # need this always selected by IOMMU for the VIA workaround
  453. config SWIOTLB
  454. bool
  455. help
  456. Support for software bounce buffers used on x86-64 systems
  457. which don't have a hardware IOMMU (e.g. the current generation
  458. of Intel's x86-64 CPUs). Using this PCI devices which can only
  459. access 32-bits of memory can be used on systems with more than
  460. 3 GB of memory. If unsure, say Y.
  461. config IOMMU_HELPER
  462. def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
  463. config MAXSMP
  464. bool "Configure Maximum number of SMP Processors and NUMA Nodes"
  465. depends on X86_64 && SMP && BROKEN
  466. default n
  467. help
  468. Configure maximum number of CPUS and NUMA Nodes for this architecture.
  469. If unsure, say N.
  470. config NR_CPUS
  471. int "Maximum number of CPUs (2-512)" if !MAXSMP
  472. range 2 512
  473. depends on SMP
  474. default "4096" if MAXSMP
  475. default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
  476. default "8"
  477. help
  478. This allows you to specify the maximum number of CPUs which this
  479. kernel will support. The maximum supported value is 512 and the
  480. minimum value which makes sense is 2.
  481. This is purely to save memory - each supported CPU adds
  482. approximately eight kilobytes to the kernel image.
  483. config SCHED_SMT
  484. bool "SMT (Hyperthreading) scheduler support"
  485. depends on X86_HT
  486. help
  487. SMT scheduler support improves the CPU scheduler's decision making
  488. when dealing with Intel Pentium 4 chips with HyperThreading at a
  489. cost of slightly increased overhead in some places. If unsure say
  490. N here.
  491. config SCHED_MC
  492. def_bool y
  493. prompt "Multi-core scheduler support"
  494. depends on X86_HT
  495. help
  496. Multi-core scheduler support improves the CPU scheduler's decision
  497. making when dealing with multi-core CPU chips at a cost of slightly
  498. increased overhead in some places. If unsure say N here.
  499. source "kernel/Kconfig.preempt"
  500. config X86_UP_APIC
  501. bool "Local APIC support on uniprocessors"
  502. depends on X86_32 && !SMP && !(X86_VOYAGER || X86_GENERICARCH)
  503. help
  504. A local APIC (Advanced Programmable Interrupt Controller) is an
  505. integrated interrupt controller in the CPU. If you have a single-CPU
  506. system which has a processor with a local APIC, you can say Y here to
  507. enable and use it. If you say Y here even though your machine doesn't
  508. have a local APIC, then the kernel will still run with no slowdown at
  509. all. The local APIC supports CPU-generated self-interrupts (timer,
  510. performance counters), and the NMI watchdog which detects hard
  511. lockups.
  512. config X86_UP_IOAPIC
  513. bool "IO-APIC support on uniprocessors"
  514. depends on X86_UP_APIC
  515. help
  516. An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
  517. SMP-capable replacement for PC-style interrupt controllers. Most
  518. SMP systems and many recent uniprocessor systems have one.
  519. If you have a single-CPU system with an IO-APIC, you can say Y here
  520. to use it. If you say Y here even though your machine doesn't have
  521. an IO-APIC, then the kernel will still run with no slowdown at all.
  522. config X86_LOCAL_APIC
  523. def_bool y
  524. depends on X86_64 || (X86_32 && (X86_UP_APIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH))
  525. config X86_IO_APIC
  526. def_bool y
  527. depends on X86_64 || (X86_32 && (X86_UP_IOAPIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH))
  528. config X86_VISWS_APIC
  529. def_bool y
  530. depends on X86_32 && X86_VISWS
  531. config X86_MCE
  532. bool "Machine Check Exception"
  533. depends on !X86_VOYAGER
  534. ---help---
  535. Machine Check Exception support allows the processor to notify the
  536. kernel if it detects a problem (e.g. overheating, component failure).
  537. The action the kernel takes depends on the severity of the problem,
  538. ranging from a warning message on the console, to halting the machine.
  539. Your processor must be a Pentium or newer to support this - check the
  540. flags in /proc/cpuinfo for mce. Note that some older Pentium systems
  541. have a design flaw which leads to false MCE events - hence MCE is
  542. disabled on all P5 processors, unless explicitly enabled with "mce"
  543. as a boot argument. Similarly, if MCE is built in and creates a
  544. problem on some new non-standard machine, you can boot with "nomce"
  545. to disable it. MCE support simply ignores non-MCE processors like
  546. the 386 and 486, so nearly everyone can say Y here.
  547. config X86_MCE_INTEL
  548. def_bool y
  549. prompt "Intel MCE features"
  550. depends on X86_64 && X86_MCE && X86_LOCAL_APIC
  551. help
  552. Additional support for intel specific MCE features such as
  553. the thermal monitor.
  554. config X86_MCE_AMD
  555. def_bool y
  556. prompt "AMD MCE features"
  557. depends on X86_64 && X86_MCE && X86_LOCAL_APIC
  558. help
  559. Additional support for AMD specific MCE features such as
  560. the DRAM Error Threshold.
  561. config X86_MCE_NONFATAL
  562. tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
  563. depends on X86_32 && X86_MCE
  564. help
  565. Enabling this feature starts a timer that triggers every 5 seconds which
  566. will look at the machine check registers to see if anything happened.
  567. Non-fatal problems automatically get corrected (but still logged).
  568. Disable this if you don't want to see these messages.
  569. Seeing the messages this option prints out may be indicative of dying
  570. or out-of-spec (ie, overclocked) hardware.
  571. This option only does something on certain CPUs.
  572. (AMD Athlon/Duron and Intel Pentium 4)
  573. config X86_MCE_P4THERMAL
  574. bool "check for P4 thermal throttling interrupt."
  575. depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP)
  576. help
  577. Enabling this feature will cause a message to be printed when the P4
  578. enters thermal throttling.
  579. config VM86
  580. bool "Enable VM86 support" if EMBEDDED
  581. default y
  582. depends on X86_32
  583. help
  584. This option is required by programs like DOSEMU to run 16-bit legacy
  585. code on X86 processors. It also may be needed by software like
  586. XFree86 to initialize some video cards via BIOS. Disabling this
  587. option saves about 6k.
  588. config TOSHIBA
  589. tristate "Toshiba Laptop support"
  590. depends on X86_32
  591. ---help---
  592. This adds a driver to safely access the System Management Mode of
  593. the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
  594. not work on models with a Phoenix BIOS. The System Management Mode
  595. is used to set the BIOS and power saving options on Toshiba portables.
  596. For information on utilities to make use of this driver see the
  597. Toshiba Linux utilities web site at:
  598. <http://www.buzzard.org.uk/toshiba/>.
  599. Say Y if you intend to run this kernel on a Toshiba portable.
  600. Say N otherwise.
  601. config I8K
  602. tristate "Dell laptop support"
  603. ---help---
  604. This adds a driver to safely access the System Management Mode
  605. of the CPU on the Dell Inspiron 8000. The System Management Mode
  606. is used to read cpu temperature and cooling fan status and to
  607. control the fans on the I8K portables.
  608. This driver has been tested only on the Inspiron 8000 but it may
  609. also work with other Dell laptops. You can force loading on other
  610. models by passing the parameter `force=1' to the module. Use at
  611. your own risk.
  612. For information on utilities to make use of this driver see the
  613. I8K Linux utilities web site at:
  614. <http://people.debian.org/~dz/i8k/>
  615. Say Y if you intend to run this kernel on a Dell Inspiron 8000.
  616. Say N otherwise.
  617. config X86_REBOOTFIXUPS
  618. def_bool n
  619. prompt "Enable X86 board specific fixups for reboot"
  620. depends on X86_32 && X86
  621. ---help---
  622. This enables chipset and/or board specific fixups to be done
  623. in order to get reboot to work correctly. This is only needed on
  624. some combinations of hardware and BIOS. The symptom, for which
  625. this config is intended, is when reboot ends with a stalled/hung
  626. system.
  627. Currently, the only fixup is for the Geode machines using
  628. CS5530A and CS5536 chipsets and the RDC R-321x SoC.
  629. Say Y if you want to enable the fixup. Currently, it's safe to
  630. enable this option even if you don't need it.
  631. Say N otherwise.
  632. config MICROCODE
  633. tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
  634. select FW_LOADER
  635. ---help---
  636. If you say Y here, you will be able to update the microcode on
  637. Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
  638. Pentium III, Pentium 4, Xeon etc. You will obviously need the
  639. actual microcode binary data itself which is not shipped with the
  640. Linux kernel.
  641. For latest news and information on obtaining all the required
  642. ingredients for this driver, check:
  643. <http://www.urbanmyth.org/microcode/>.
  644. To compile this driver as a module, choose M here: the
  645. module will be called microcode.
  646. config MICROCODE_OLD_INTERFACE
  647. def_bool y
  648. depends on MICROCODE
  649. config X86_MSR
  650. tristate "/dev/cpu/*/msr - Model-specific register support"
  651. help
  652. This device gives privileged processes access to the x86
  653. Model-Specific Registers (MSRs). It is a character device with
  654. major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
  655. MSR accesses are directed to a specific CPU on multi-processor
  656. systems.
  657. config X86_CPUID
  658. tristate "/dev/cpu/*/cpuid - CPU information support"
  659. help
  660. This device gives processes access to the x86 CPUID instruction to
  661. be executed on a specific processor. It is a character device
  662. with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
  663. /dev/cpu/31/cpuid.
  664. choice
  665. prompt "High Memory Support"
  666. default HIGHMEM4G if !X86_NUMAQ
  667. default HIGHMEM64G if X86_NUMAQ
  668. depends on X86_32
  669. config NOHIGHMEM
  670. bool "off"
  671. depends on !X86_NUMAQ
  672. ---help---
  673. Linux can use up to 64 Gigabytes of physical memory on x86 systems.
  674. However, the address space of 32-bit x86 processors is only 4
  675. Gigabytes large. That means that, if you have a large amount of
  676. physical memory, not all of it can be "permanently mapped" by the
  677. kernel. The physical memory that's not permanently mapped is called
  678. "high memory".
  679. If you are compiling a kernel which will never run on a machine with
  680. more than 1 Gigabyte total physical RAM, answer "off" here (default
  681. choice and suitable for most users). This will result in a "3GB/1GB"
  682. split: 3GB are mapped so that each process sees a 3GB virtual memory
  683. space and the remaining part of the 4GB virtual memory space is used
  684. by the kernel to permanently map as much physical memory as
  685. possible.
  686. If the machine has between 1 and 4 Gigabytes physical RAM, then
  687. answer "4GB" here.
  688. If more than 4 Gigabytes is used then answer "64GB" here. This
  689. selection turns Intel PAE (Physical Address Extension) mode on.
  690. PAE implements 3-level paging on IA32 processors. PAE is fully
  691. supported by Linux, PAE mode is implemented on all recent Intel
  692. processors (Pentium Pro and better). NOTE: If you say "64GB" here,
  693. then the kernel will not boot on CPUs that don't support PAE!
  694. The actual amount of total physical memory will either be
  695. auto detected or can be forced by using a kernel command line option
  696. such as "mem=256M". (Try "man bootparam" or see the documentation of
  697. your boot loader (lilo or loadlin) about how to pass options to the
  698. kernel at boot time.)
  699. If unsure, say "off".
  700. config HIGHMEM4G
  701. bool "4GB"
  702. depends on !X86_NUMAQ
  703. help
  704. Select this if you have a 32-bit processor and between 1 and 4
  705. gigabytes of physical RAM.
  706. config HIGHMEM64G
  707. bool "64GB"
  708. depends on !M386 && !M486
  709. select X86_PAE
  710. help
  711. Select this if you have a 32-bit processor and more than 4
  712. gigabytes of physical RAM.
  713. endchoice
  714. choice
  715. depends on EXPERIMENTAL
  716. prompt "Memory split" if EMBEDDED
  717. default VMSPLIT_3G
  718. depends on X86_32
  719. help
  720. Select the desired split between kernel and user memory.
  721. If the address range available to the kernel is less than the
  722. physical memory installed, the remaining memory will be available
  723. as "high memory". Accessing high memory is a little more costly
  724. than low memory, as it needs to be mapped into the kernel first.
  725. Note that increasing the kernel address space limits the range
  726. available to user programs, making the address space there
  727. tighter. Selecting anything other than the default 3G/1G split
  728. will also likely make your kernel incompatible with binary-only
  729. kernel modules.
  730. If you are not absolutely sure what you are doing, leave this
  731. option alone!
  732. config VMSPLIT_3G
  733. bool "3G/1G user/kernel split"
  734. config VMSPLIT_3G_OPT
  735. depends on !X86_PAE
  736. bool "3G/1G user/kernel split (for full 1G low memory)"
  737. config VMSPLIT_2G
  738. bool "2G/2G user/kernel split"
  739. config VMSPLIT_2G_OPT
  740. depends on !X86_PAE
  741. bool "2G/2G user/kernel split (for full 2G low memory)"
  742. config VMSPLIT_1G
  743. bool "1G/3G user/kernel split"
  744. endchoice
  745. config PAGE_OFFSET
  746. hex
  747. default 0xB0000000 if VMSPLIT_3G_OPT
  748. default 0x80000000 if VMSPLIT_2G
  749. default 0x78000000 if VMSPLIT_2G_OPT
  750. default 0x40000000 if VMSPLIT_1G
  751. default 0xC0000000
  752. depends on X86_32
  753. config HIGHMEM
  754. def_bool y
  755. depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
  756. config X86_PAE
  757. def_bool n
  758. prompt "PAE (Physical Address Extension) Support"
  759. depends on X86_32 && !HIGHMEM4G
  760. select RESOURCES_64BIT
  761. help
  762. PAE is required for NX support, and furthermore enables
  763. larger swapspace support for non-overcommit purposes. It
  764. has the cost of more pagetable lookup overhead, and also
  765. consumes more pagetable space per process.
  766. # Common NUMA Features
  767. config NUMA
  768. bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)"
  769. depends on SMP
  770. depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
  771. default n if X86_PC
  772. default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
  773. help
  774. Enable NUMA (Non Uniform Memory Access) support.
  775. The kernel will try to allocate memory used by a CPU on the
  776. local memory controller of the CPU and add some more
  777. NUMA awareness to the kernel.
  778. For 32-bit this is currently highly experimental and should be only
  779. used for kernel development. It might also cause boot failures.
  780. For 64-bit this is recommended on all multiprocessor Opteron systems.
  781. If the system is EM64T, you should say N unless your system is
  782. EM64T NUMA.
  783. comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
  784. depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
  785. config K8_NUMA
  786. def_bool y
  787. prompt "Old style AMD Opteron NUMA detection"
  788. depends on X86_64 && NUMA && PCI
  789. help
  790. Enable K8 NUMA node topology detection. You should say Y here if
  791. you have a multi processor AMD K8 system. This uses an old
  792. method to read the NUMA configuration directly from the builtin
  793. Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
  794. instead, which also takes priority if both are compiled in.
  795. config X86_64_ACPI_NUMA
  796. def_bool y
  797. prompt "ACPI NUMA detection"
  798. depends on X86_64 && NUMA && ACPI && PCI
  799. select ACPI_NUMA
  800. help
  801. Enable ACPI SRAT based node topology detection.
  802. # Some NUMA nodes have memory ranges that span
  803. # other nodes. Even though a pfn is valid and
  804. # between a node's start and end pfns, it may not
  805. # reside on that node. See memmap_init_zone()
  806. # for details.
  807. config NODES_SPAN_OTHER_NODES
  808. def_bool y
  809. depends on X86_64_ACPI_NUMA
  810. config NUMA_EMU
  811. bool "NUMA emulation"
  812. depends on X86_64 && NUMA
  813. help
  814. Enable NUMA emulation. A flat machine will be split
  815. into virtual nodes when booted with "numa=fake=N", where N is the
  816. number of nodes. This is only useful for debugging.
  817. config NODES_SHIFT
  818. int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
  819. range 1 9 if X86_64
  820. default "9" if MAXSMP
  821. default "6" if X86_64
  822. default "4" if X86_NUMAQ
  823. default "3"
  824. depends on NEED_MULTIPLE_NODES
  825. help
  826. Specify the maximum number of NUMA Nodes available on the target
  827. system. Increases memory reserved to accomodate various tables.
  828. config HAVE_ARCH_BOOTMEM_NODE
  829. def_bool y
  830. depends on X86_32 && NUMA
  831. config ARCH_HAVE_MEMORY_PRESENT
  832. def_bool y
  833. depends on X86_32 && DISCONTIGMEM
  834. config NEED_NODE_MEMMAP_SIZE
  835. def_bool y
  836. depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
  837. config HAVE_ARCH_ALLOC_REMAP
  838. def_bool y
  839. depends on X86_32 && NUMA
  840. config ARCH_FLATMEM_ENABLE
  841. def_bool y
  842. depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && X86_PC && !NUMA
  843. config ARCH_DISCONTIGMEM_ENABLE
  844. def_bool y
  845. depends on NUMA && X86_32
  846. config ARCH_DISCONTIGMEM_DEFAULT
  847. def_bool y
  848. depends on NUMA && X86_32
  849. config ARCH_SPARSEMEM_DEFAULT
  850. def_bool y
  851. depends on X86_64
  852. config ARCH_SPARSEMEM_ENABLE
  853. def_bool y
  854. depends on X86_64 || NUMA || (EXPERIMENTAL && X86_PC)
  855. select SPARSEMEM_STATIC if X86_32
  856. select SPARSEMEM_VMEMMAP_ENABLE if X86_64
  857. config ARCH_SELECT_MEMORY_MODEL
  858. def_bool y
  859. depends on ARCH_SPARSEMEM_ENABLE
  860. config ARCH_MEMORY_PROBE
  861. def_bool X86_64
  862. depends on MEMORY_HOTPLUG
  863. source "mm/Kconfig"
  864. config HIGHPTE
  865. bool "Allocate 3rd-level pagetables from highmem"
  866. depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
  867. help
  868. The VM uses one page table entry for each page of physical memory.
  869. For systems with a lot of RAM, this can be wasteful of precious
  870. low memory. Setting this option will put user-space page table
  871. entries in high memory.
  872. config MATH_EMULATION
  873. bool
  874. prompt "Math emulation" if X86_32
  875. ---help---
  876. Linux can emulate a math coprocessor (used for floating point
  877. operations) if you don't have one. 486DX and Pentium processors have
  878. a math coprocessor built in, 486SX and 386 do not, unless you added
  879. a 487DX or 387, respectively. (The messages during boot time can
  880. give you some hints here ["man dmesg"].) Everyone needs either a
  881. coprocessor or this emulation.
  882. If you don't have a math coprocessor, you need to say Y here; if you
  883. say Y here even though you have a coprocessor, the coprocessor will
  884. be used nevertheless. (This behavior can be changed with the kernel
  885. command line option "no387", which comes handy if your coprocessor
  886. is broken. Try "man bootparam" or see the documentation of your boot
  887. loader (lilo or loadlin) about how to pass options to the kernel at
  888. boot time.) This means that it is a good idea to say Y here if you
  889. intend to use this kernel on different machines.
  890. More information about the internals of the Linux math coprocessor
  891. emulation can be found in <file:arch/x86/math-emu/README>.
  892. If you are not sure, say Y; apart from resulting in a 66 KB bigger
  893. kernel, it won't hurt.
  894. config MTRR
  895. bool "MTRR (Memory Type Range Register) support"
  896. ---help---
  897. On Intel P6 family processors (Pentium Pro, Pentium II and later)
  898. the Memory Type Range Registers (MTRRs) may be used to control
  899. processor access to memory ranges. This is most useful if you have
  900. a video (VGA) card on a PCI or AGP bus. Enabling write-combining
  901. allows bus write transfers to be combined into a larger transfer
  902. before bursting over the PCI/AGP bus. This can increase performance
  903. of image write operations 2.5 times or more. Saying Y here creates a
  904. /proc/mtrr file which may be used to manipulate your processor's
  905. MTRRs. Typically the X server should use this.
  906. This code has a reasonably generic interface so that similar
  907. control registers on other processors can be easily supported
  908. as well:
  909. The Cyrix 6x86, 6x86MX and M II processors have Address Range
  910. Registers (ARRs) which provide a similar functionality to MTRRs. For
  911. these, the ARRs are used to emulate the MTRRs.
  912. The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
  913. MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
  914. write-combining. All of these processors are supported by this code
  915. and it makes sense to say Y here if you have one of them.
  916. Saying Y here also fixes a problem with buggy SMP BIOSes which only
  917. set the MTRRs for the boot CPU and not for the secondary CPUs. This
  918. can lead to all sorts of problems, so it's good to say Y here.
  919. You can safely say Y even if your machine doesn't have MTRRs, you'll
  920. just add about 9 KB to your kernel.
  921. See <file:Documentation/mtrr.txt> for more information.
  922. config MTRR_SANITIZER
  923. bool
  924. prompt "MTRR cleanup support"
  925. depends on MTRR
  926. help
  927. Convert MTRR layout from continuous to discrete, so X drivers can
  928. add writeback entries.
  929. Can be disabled with disable_mtrr_cleanup on the kernel command line.
  930. The largest mtrr entry size for a continous block can be set with
  931. mtrr_chunk_size.
  932. If unsure, say N.
  933. config MTRR_SANITIZER_ENABLE_DEFAULT
  934. int "MTRR cleanup enable value (0-1)"
  935. range 0 1
  936. default "0"
  937. depends on MTRR_SANITIZER
  938. help
  939. Enable mtrr cleanup default value
  940. config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
  941. int "MTRR cleanup spare reg num (0-7)"
  942. range 0 7
  943. default "1"
  944. depends on MTRR_SANITIZER
  945. help
  946. mtrr cleanup spare entries default, it can be changed via
  947. mtrr_spare_reg_nr=N on the kernel command line.
  948. config X86_PAT
  949. bool
  950. prompt "x86 PAT support"
  951. depends on MTRR
  952. help
  953. Use PAT attributes to setup page level cache control.
  954. PATs are the modern equivalents of MTRRs and are much more
  955. flexible than MTRRs.
  956. Say N here if you see bootup problems (boot crash, boot hang,
  957. spontaneous reboots) or a non-working video driver.
  958. If unsure, say Y.
  959. config EFI
  960. def_bool n
  961. prompt "EFI runtime service support"
  962. depends on ACPI
  963. ---help---
  964. This enables the kernel to use EFI runtime services that are
  965. available (such as the EFI variable services).
  966. This option is only useful on systems that have EFI firmware.
  967. In addition, you should use the latest ELILO loader available
  968. at <http://elilo.sourceforge.net> in order to take advantage
  969. of EFI runtime services. However, even with this option, the
  970. resultant kernel should continue to boot on existing non-EFI
  971. platforms.
  972. config IRQBALANCE
  973. def_bool y
  974. prompt "Enable kernel irq balancing"
  975. depends on X86_32 && SMP && X86_IO_APIC
  976. help
  977. The default yes will allow the kernel to do irq load balancing.
  978. Saying no will keep the kernel from doing irq load balancing.
  979. config SECCOMP
  980. def_bool y
  981. prompt "Enable seccomp to safely compute untrusted bytecode"
  982. depends on PROC_FS
  983. help
  984. This kernel feature is useful for number crunching applications
  985. that may need to compute untrusted bytecode during their
  986. execution. By using pipes or other transports made available to
  987. the process as file descriptors supporting the read/write
  988. syscalls, it's possible to isolate those applications in
  989. their own address space using seccomp. Once seccomp is
  990. enabled via /proc/<pid>/seccomp, it cannot be disabled
  991. and the task is only allowed to execute a few safe syscalls
  992. defined by each seccomp mode.
  993. If unsure, say Y. Only embedded should say N here.
  994. config CC_STACKPROTECTOR
  995. bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
  996. depends on X86_64 && EXPERIMENTAL && BROKEN
  997. help
  998. This option turns on the -fstack-protector GCC feature. This
  999. feature puts, at the beginning of critical functions, a canary
  1000. value on the stack just before the return address, and validates
  1001. the value just before actually returning. Stack based buffer
  1002. overflows (that need to overwrite this return address) now also
  1003. overwrite the canary, which gets detected and the attack is then
  1004. neutralized via a kernel panic.
  1005. This feature requires gcc version 4.2 or above, or a distribution
  1006. gcc with the feature backported. Older versions are automatically
  1007. detected and for those versions, this configuration option is ignored.
  1008. config CC_STACKPROTECTOR_ALL
  1009. bool "Use stack-protector for all functions"
  1010. depends on CC_STACKPROTECTOR
  1011. help
  1012. Normally, GCC only inserts the canary value protection for
  1013. functions that use large-ish on-stack buffers. By enabling
  1014. this option, GCC will be asked to do this for ALL functions.
  1015. source kernel/Kconfig.hz
  1016. config KEXEC
  1017. bool "kexec system call"
  1018. depends on X86_BIOS_REBOOT
  1019. help
  1020. kexec is a system call that implements the ability to shutdown your
  1021. current kernel, and to start another kernel. It is like a reboot
  1022. but it is independent of the system firmware. And like a reboot
  1023. you can start any kernel with it, not just Linux.
  1024. The name comes from the similarity to the exec system call.
  1025. It is an ongoing process to be certain the hardware in a machine
  1026. is properly shutdown, so do not be surprised if this code does not
  1027. initially work for you. It may help to enable device hotplugging
  1028. support. As of this writing the exact hardware interface is
  1029. strongly in flux, so no good recommendation can be made.
  1030. config CRASH_DUMP
  1031. bool "kernel crash dumps"
  1032. depends on X86_64 || (X86_32 && HIGHMEM)
  1033. help
  1034. Generate crash dump after being started by kexec.
  1035. This should be normally only set in special crash dump kernels
  1036. which are loaded in the main kernel with kexec-tools into
  1037. a specially reserved region and then later executed after
  1038. a crash by kdump/kexec. The crash dump kernel must be compiled
  1039. to a memory address not used by the main kernel or BIOS using
  1040. PHYSICAL_START, or it must be built as a relocatable image
  1041. (CONFIG_RELOCATABLE=y).
  1042. For more details see Documentation/kdump/kdump.txt
  1043. config KEXEC_JUMP
  1044. bool "kexec jump (EXPERIMENTAL)"
  1045. depends on EXPERIMENTAL
  1046. depends on KEXEC && HIBERNATION && X86_32
  1047. help
  1048. Jump between original kernel and kexeced kernel and invoke
  1049. code in physical address mode via KEXEC
  1050. config PHYSICAL_START
  1051. hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
  1052. default "0x1000000" if X86_NUMAQ
  1053. default "0x200000" if X86_64
  1054. default "0x100000"
  1055. help
  1056. This gives the physical address where the kernel is loaded.
  1057. If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
  1058. bzImage will decompress itself to above physical address and
  1059. run from there. Otherwise, bzImage will run from the address where
  1060. it has been loaded by the boot loader and will ignore above physical
  1061. address.
  1062. In normal kdump cases one does not have to set/change this option
  1063. as now bzImage can be compiled as a completely relocatable image
  1064. (CONFIG_RELOCATABLE=y) and be used to load and run from a different
  1065. address. This option is mainly useful for the folks who don't want
  1066. to use a bzImage for capturing the crash dump and want to use a
  1067. vmlinux instead. vmlinux is not relocatable hence a kernel needs
  1068. to be specifically compiled to run from a specific memory area
  1069. (normally a reserved region) and this option comes handy.
  1070. So if you are using bzImage for capturing the crash dump, leave
  1071. the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
  1072. Otherwise if you plan to use vmlinux for capturing the crash dump
  1073. change this value to start of the reserved region (Typically 16MB
  1074. 0x1000000). In other words, it can be set based on the "X" value as
  1075. specified in the "crashkernel=YM@XM" command line boot parameter
  1076. passed to the panic-ed kernel. Typically this parameter is set as
  1077. crashkernel=64M@16M. Please take a look at
  1078. Documentation/kdump/kdump.txt for more details about crash dumps.
  1079. Usage of bzImage for capturing the crash dump is recommended as
  1080. one does not have to build two kernels. Same kernel can be used
  1081. as production kernel and capture kernel. Above option should have
  1082. gone away after relocatable bzImage support is introduced. But it
  1083. is present because there are users out there who continue to use
  1084. vmlinux for dump capture. This option should go away down the
  1085. line.
  1086. Don't change this unless you know what you are doing.
  1087. config RELOCATABLE
  1088. bool "Build a relocatable kernel (EXPERIMENTAL)"
  1089. depends on EXPERIMENTAL
  1090. help
  1091. This builds a kernel image that retains relocation information
  1092. so it can be loaded someplace besides the default 1MB.
  1093. The relocations tend to make the kernel binary about 10% larger,
  1094. but are discarded at runtime.
  1095. One use is for the kexec on panic case where the recovery kernel
  1096. must live at a different physical address than the primary
  1097. kernel.
  1098. Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
  1099. it has been loaded at and the compile time physical address
  1100. (CONFIG_PHYSICAL_START) is ignored.
  1101. config PHYSICAL_ALIGN
  1102. hex
  1103. prompt "Alignment value to which kernel should be aligned" if X86_32
  1104. default "0x100000" if X86_32
  1105. default "0x200000" if X86_64
  1106. range 0x2000 0x400000
  1107. help
  1108. This value puts the alignment restrictions on physical address
  1109. where kernel is loaded and run from. Kernel is compiled for an
  1110. address which meets above alignment restriction.
  1111. If bootloader loads the kernel at a non-aligned address and
  1112. CONFIG_RELOCATABLE is set, kernel will move itself to nearest
  1113. address aligned to above value and run from there.
  1114. If bootloader loads the kernel at a non-aligned address and
  1115. CONFIG_RELOCATABLE is not set, kernel will ignore the run time
  1116. load address and decompress itself to the address it has been
  1117. compiled for and run from there. The address for which kernel is
  1118. compiled already meets above alignment restrictions. Hence the
  1119. end result is that kernel runs from a physical address meeting
  1120. above alignment restrictions.
  1121. Don't change this unless you know what you are doing.
  1122. config HOTPLUG_CPU
  1123. bool "Support for suspend on SMP and hot-pluggable CPUs (EXPERIMENTAL)"
  1124. depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
  1125. ---help---
  1126. Say Y here to experiment with turning CPUs off and on, and to
  1127. enable suspend on SMP systems. CPUs can be controlled through
  1128. /sys/devices/system/cpu.
  1129. Say N if you want to disable CPU hotplug and don't need to
  1130. suspend.
  1131. config COMPAT_VDSO
  1132. def_bool y
  1133. prompt "Compat VDSO support"
  1134. depends on X86_32 || IA32_EMULATION
  1135. help
  1136. Map the 32-bit VDSO to the predictable old-style address too.
  1137. ---help---
  1138. Say N here if you are running a sufficiently recent glibc
  1139. version (2.3.3 or later), to remove the high-mapped
  1140. VDSO mapping and to exclusively use the randomized VDSO.
  1141. If unsure, say Y.
  1142. endmenu
  1143. config ARCH_ENABLE_MEMORY_HOTPLUG
  1144. def_bool y
  1145. depends on X86_64 || (X86_32 && HIGHMEM)
  1146. config HAVE_ARCH_EARLY_PFN_TO_NID
  1147. def_bool X86_64
  1148. depends on NUMA
  1149. menu "Power management options"
  1150. depends on !X86_VOYAGER
  1151. config ARCH_HIBERNATION_HEADER
  1152. def_bool y
  1153. depends on X86_64 && HIBERNATION
  1154. source "kernel/power/Kconfig"
  1155. source "drivers/acpi/Kconfig"
  1156. config X86_APM_BOOT
  1157. bool
  1158. default y
  1159. depends on APM || APM_MODULE
  1160. menuconfig APM
  1161. tristate "APM (Advanced Power Management) BIOS support"
  1162. depends on X86_32 && PM_SLEEP
  1163. ---help---
  1164. APM is a BIOS specification for saving power using several different
  1165. techniques. This is mostly useful for battery powered laptops with
  1166. APM compliant BIOSes. If you say Y here, the system time will be
  1167. reset after a RESUME operation, the /proc/apm device will provide
  1168. battery status information, and user-space programs will receive
  1169. notification of APM "events" (e.g. battery status change).
  1170. If you select "Y" here, you can disable actual use of the APM
  1171. BIOS by passing the "apm=off" option to the kernel at boot time.
  1172. Note that the APM support is almost completely disabled for
  1173. machines with more than one CPU.
  1174. In order to use APM, you will need supporting software. For location
  1175. and more information, read <file:Documentation/power/pm.txt> and the
  1176. Battery Powered Linux mini-HOWTO, available from
  1177. <http://www.tldp.org/docs.html#howto>.
  1178. This driver does not spin down disk drives (see the hdparm(8)
  1179. manpage ("man 8 hdparm") for that), and it doesn't turn off
  1180. VESA-compliant "green" monitors.
  1181. This driver does not support the TI 4000M TravelMate and the ACER
  1182. 486/DX4/75 because they don't have compliant BIOSes. Many "green"
  1183. desktop machines also don't have compliant BIOSes, and this driver
  1184. may cause those machines to panic during the boot phase.
  1185. Generally, if you don't have a battery in your machine, there isn't
  1186. much point in using this driver and you should say N. If you get
  1187. random kernel OOPSes or reboots that don't seem to be related to
  1188. anything, try disabling/enabling this option (or disabling/enabling
  1189. APM in your BIOS).
  1190. Some other things you should try when experiencing seemingly random,
  1191. "weird" problems:
  1192. 1) make sure that you have enough swap space and that it is
  1193. enabled.
  1194. 2) pass the "no-hlt" option to the kernel
  1195. 3) switch on floating point emulation in the kernel and pass
  1196. the "no387" option to the kernel
  1197. 4) pass the "floppy=nodma" option to the kernel
  1198. 5) pass the "mem=4M" option to the kernel (thereby disabling
  1199. all but the first 4 MB of RAM)
  1200. 6) make sure that the CPU is not over clocked.
  1201. 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
  1202. 8) disable the cache from your BIOS settings
  1203. 9) install a fan for the video card or exchange video RAM
  1204. 10) install a better fan for the CPU
  1205. 11) exchange RAM chips
  1206. 12) exchange the motherboard.
  1207. To compile this driver as a module, choose M here: the
  1208. module will be called apm.
  1209. if APM
  1210. config APM_IGNORE_USER_SUSPEND
  1211. bool "Ignore USER SUSPEND"
  1212. help
  1213. This option will ignore USER SUSPEND requests. On machines with a
  1214. compliant APM BIOS, you want to say N. However, on the NEC Versa M
  1215. series notebooks, it is necessary to say Y because of a BIOS bug.
  1216. config APM_DO_ENABLE
  1217. bool "Enable PM at boot time"
  1218. ---help---
  1219. Enable APM features at boot time. From page 36 of the APM BIOS
  1220. specification: "When disabled, the APM BIOS does not automatically
  1221. power manage devices, enter the Standby State, enter the Suspend
  1222. State, or take power saving steps in response to CPU Idle calls."
  1223. This driver will make CPU Idle calls when Linux is idle (unless this
  1224. feature is turned off -- see "Do CPU IDLE calls", below). This
  1225. should always save battery power, but more complicated APM features
  1226. will be dependent on your BIOS implementation. You may need to turn
  1227. this option off if your computer hangs at boot time when using APM
  1228. support, or if it beeps continuously instead of suspending. Turn
  1229. this off if you have a NEC UltraLite Versa 33/C or a Toshiba
  1230. T400CDT. This is off by default since most machines do fine without
  1231. this feature.
  1232. config APM_CPU_IDLE
  1233. bool "Make CPU Idle calls when idle"
  1234. help
  1235. Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
  1236. On some machines, this can activate improved power savings, such as
  1237. a slowed CPU clock rate, when the machine is idle. These idle calls
  1238. are made after the idle loop has run for some length of time (e.g.,
  1239. 333 mS). On some machines, this will cause a hang at boot time or
  1240. whenever the CPU becomes idle. (On machines with more than one CPU,
  1241. this option does nothing.)
  1242. config APM_DISPLAY_BLANK
  1243. bool "Enable console blanking using APM"
  1244. help
  1245. Enable console blanking using the APM. Some laptops can use this to
  1246. turn off the LCD backlight when the screen blanker of the Linux
  1247. virtual console blanks the screen. Note that this is only used by
  1248. the virtual console screen blanker, and won't turn off the backlight
  1249. when using the X Window system. This also doesn't have anything to
  1250. do with your VESA-compliant power-saving monitor. Further, this
  1251. option doesn't work for all laptops -- it might not turn off your
  1252. backlight at all, or it might print a lot of errors to the console,
  1253. especially if you are using gpm.
  1254. config APM_ALLOW_INTS
  1255. bool "Allow interrupts during APM BIOS calls"
  1256. help
  1257. Normally we disable external interrupts while we are making calls to
  1258. the APM BIOS as a measure to lessen the effects of a badly behaving
  1259. BIOS implementation. The BIOS should reenable interrupts if it
  1260. needs to. Unfortunately, some BIOSes do not -- especially those in
  1261. many of the newer IBM Thinkpads. If you experience hangs when you
  1262. suspend, try setting this to Y. Otherwise, say N.
  1263. config APM_REAL_MODE_POWER_OFF
  1264. bool "Use real mode APM BIOS call to power off"
  1265. help
  1266. Use real mode APM BIOS calls to switch off the computer. This is
  1267. a work-around for a number of buggy BIOSes. Switch this option on if
  1268. your computer crashes instead of powering off properly.
  1269. endif # APM
  1270. source "arch/x86/kernel/cpu/cpufreq/Kconfig"
  1271. source "drivers/cpuidle/Kconfig"
  1272. endmenu
  1273. menu "Bus options (PCI etc.)"
  1274. config PCI
  1275. bool "PCI support"
  1276. default y
  1277. select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
  1278. help
  1279. Find out whether you have a PCI motherboard. PCI is the name of a
  1280. bus system, i.e. the way the CPU talks to the other stuff inside
  1281. your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
  1282. VESA. If you have PCI, say Y, otherwise N.
  1283. choice
  1284. prompt "PCI access mode"
  1285. depends on X86_32 && PCI
  1286. default PCI_GOANY
  1287. ---help---
  1288. On PCI systems, the BIOS can be used to detect the PCI devices and
  1289. determine their configuration. However, some old PCI motherboards
  1290. have BIOS bugs and may crash if this is done. Also, some embedded
  1291. PCI-based systems don't have any BIOS at all. Linux can also try to
  1292. detect the PCI hardware directly without using the BIOS.
  1293. With this option, you can specify how Linux should detect the
  1294. PCI devices. If you choose "BIOS", the BIOS will be used,
  1295. if you choose "Direct", the BIOS won't be used, and if you
  1296. choose "MMConfig", then PCI Express MMCONFIG will be used.
  1297. If you choose "Any", the kernel will try MMCONFIG, then the
  1298. direct access method and falls back to the BIOS if that doesn't
  1299. work. If unsure, go with the default, which is "Any".
  1300. config PCI_GOBIOS
  1301. bool "BIOS"
  1302. config PCI_GOMMCONFIG
  1303. bool "MMConfig"
  1304. config PCI_GODIRECT
  1305. bool "Direct"
  1306. config PCI_GOOLPC
  1307. bool "OLPC"
  1308. depends on OLPC
  1309. config PCI_GOANY
  1310. bool "Any"
  1311. endchoice
  1312. config PCI_BIOS
  1313. def_bool y
  1314. depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
  1315. # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
  1316. config PCI_DIRECT
  1317. def_bool y
  1318. depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
  1319. config PCI_MMCONFIG
  1320. def_bool y
  1321. depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
  1322. config PCI_OLPC
  1323. def_bool y
  1324. depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
  1325. config PCI_DOMAINS
  1326. def_bool y
  1327. depends on PCI
  1328. config PCI_MMCONFIG
  1329. bool "Support mmconfig PCI config space access"
  1330. depends on X86_64 && PCI && ACPI
  1331. config DMAR
  1332. bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
  1333. depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
  1334. help
  1335. DMA remapping (DMAR) devices support enables independent address
  1336. translations for Direct Memory Access (DMA) from devices.
  1337. These DMA remapping devices are reported via ACPI tables
  1338. and include PCI device scope covered by these DMA
  1339. remapping devices.
  1340. config DMAR_GFX_WA
  1341. def_bool y
  1342. prompt "Support for Graphics workaround"
  1343. depends on DMAR
  1344. help
  1345. Current Graphics drivers tend to use physical address
  1346. for DMA and avoid using DMA APIs. Setting this config
  1347. option permits the IOMMU driver to set a unity map for
  1348. all the OS-visible memory. Hence the driver can continue
  1349. to use physical addresses for DMA.
  1350. config DMAR_FLOPPY_WA
  1351. def_bool y
  1352. depends on DMAR
  1353. help
  1354. Floppy disk drivers are know to bypass DMA API calls
  1355. thereby failing to work when IOMMU is enabled. This
  1356. workaround will setup a 1:1 mapping for the first
  1357. 16M to make floppy (an ISA device) work.
  1358. source "drivers/pci/pcie/Kconfig"
  1359. source "drivers/pci/Kconfig"
  1360. # x86_64 have no ISA slots, but do have ISA-style DMA.
  1361. config ISA_DMA_API
  1362. def_bool y
  1363. if X86_32
  1364. config ISA
  1365. bool "ISA support"
  1366. depends on !X86_VOYAGER
  1367. help
  1368. Find out whether you have ISA slots on your motherboard. ISA is the
  1369. name of a bus system, i.e. the way the CPU talks to the other stuff
  1370. inside your box. Other bus systems are PCI, EISA, MicroChannel
  1371. (MCA) or VESA. ISA is an older system, now being displaced by PCI;
  1372. newer boards don't support it. If you have ISA, say Y, otherwise N.
  1373. config EISA
  1374. bool "EISA support"
  1375. depends on ISA
  1376. ---help---
  1377. The Extended Industry Standard Architecture (EISA) bus was
  1378. developed as an open alternative to the IBM MicroChannel bus.
  1379. The EISA bus provided some of the features of the IBM MicroChannel
  1380. bus while maintaining backward compatibility with cards made for
  1381. the older ISA bus. The EISA bus saw limited use between 1988 and
  1382. 1995 when it was made obsolete by the PCI bus.
  1383. Say Y here if you are building a kernel for an EISA-based machine.
  1384. Otherwise, say N.
  1385. source "drivers/eisa/Kconfig"
  1386. config MCA
  1387. bool "MCA support" if !X86_VOYAGER
  1388. default y if X86_VOYAGER
  1389. help
  1390. MicroChannel Architecture is found in some IBM PS/2 machines and
  1391. laptops. It is a bus system similar to PCI or ISA. See
  1392. <file:Documentation/mca.txt> (and especially the web page given
  1393. there) before attempting to build an MCA bus kernel.
  1394. source "drivers/mca/Kconfig"
  1395. config SCx200
  1396. tristate "NatSemi SCx200 support"
  1397. depends on !X86_VOYAGER
  1398. help
  1399. This provides basic support for National Semiconductor's
  1400. (now AMD's) Geode processors. The driver probes for the
  1401. PCI-IDs of several on-chip devices, so its a good dependency
  1402. for other scx200_* drivers.
  1403. If compiled as a module, the driver is named scx200.
  1404. config SCx200HR_TIMER
  1405. tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
  1406. depends on SCx200 && GENERIC_TIME
  1407. default y
  1408. help
  1409. This driver provides a clocksource built upon the on-chip
  1410. 27MHz high-resolution timer. Its also a workaround for
  1411. NSC Geode SC-1100's buggy TSC, which loses time when the
  1412. processor goes idle (as is done by the scheduler). The
  1413. other workaround is idle=poll boot option.
  1414. config GEODE_MFGPT_TIMER
  1415. def_bool y
  1416. prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
  1417. depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
  1418. help
  1419. This driver provides a clock event source based on the MFGPT
  1420. timer(s) in the CS5535 and CS5536 companion chip for the geode.
  1421. MFGPTs have a better resolution and max interval than the
  1422. generic PIT, and are suitable for use as high-res timers.
  1423. config OLPC
  1424. bool "One Laptop Per Child support"
  1425. default n
  1426. help
  1427. Add support for detecting the unique features of the OLPC
  1428. XO hardware.
  1429. endif # X86_32
  1430. config K8_NB
  1431. def_bool y
  1432. depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
  1433. source "drivers/pcmcia/Kconfig"
  1434. source "drivers/pci/hotplug/Kconfig"
  1435. endmenu
  1436. menu "Executable file formats / Emulations"
  1437. source "fs/Kconfig.binfmt"
  1438. config IA32_EMULATION
  1439. bool "IA32 Emulation"
  1440. depends on X86_64
  1441. select COMPAT_BINFMT_ELF
  1442. help
  1443. Include code to run 32-bit programs under a 64-bit kernel. You should
  1444. likely turn this on, unless you're 100% sure that you don't have any
  1445. 32-bit programs left.
  1446. config IA32_AOUT
  1447. tristate "IA32 a.out support"
  1448. depends on IA32_EMULATION
  1449. help
  1450. Support old a.out binaries in the 32bit emulation.
  1451. config COMPAT
  1452. def_bool y
  1453. depends on IA32_EMULATION
  1454. config COMPAT_FOR_U64_ALIGNMENT
  1455. def_bool COMPAT
  1456. depends on X86_64
  1457. config SYSVIPC_COMPAT
  1458. def_bool y
  1459. depends on X86_64 && COMPAT && SYSVIPC
  1460. endmenu
  1461. source "net/Kconfig"
  1462. source "drivers/Kconfig"
  1463. source "drivers/firmware/Kconfig"
  1464. source "fs/Kconfig"
  1465. source "arch/x86/Kconfig.debug"
  1466. source "security/Kconfig"
  1467. source "crypto/Kconfig"
  1468. source "arch/x86/kvm/Kconfig"
  1469. source "lib/Kconfig"