Kconfig.i386 39 KB

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  1. #
  2. # For a description of the syntax of this configuration file,
  3. # see Documentation/kbuild/kconfig-language.txt.
  4. #
  5. mainmenu "Linux Kernel Configuration"
  6. config X86_32
  7. bool
  8. default y
  9. help
  10. This is Linux's home port. Linux was originally native to the Intel
  11. 386, and runs on all the later x86 processors including the Intel
  12. 486, 586, Pentiums, and various instruction-set-compatible chips by
  13. AMD, Cyrix, and others.
  14. config GENERIC_TIME
  15. bool
  16. default y
  17. config GENERIC_CMOS_UPDATE
  18. bool
  19. default y
  20. config CLOCKSOURCE_WATCHDOG
  21. bool
  22. default y
  23. config GENERIC_CLOCKEVENTS
  24. bool
  25. default y
  26. config GENERIC_CLOCKEVENTS_BROADCAST
  27. bool
  28. default y
  29. depends on X86_LOCAL_APIC
  30. config LOCKDEP_SUPPORT
  31. bool
  32. default y
  33. config STACKTRACE_SUPPORT
  34. bool
  35. default y
  36. config SEMAPHORE_SLEEPERS
  37. bool
  38. default y
  39. config X86
  40. bool
  41. default y
  42. config MMU
  43. bool
  44. default y
  45. config ZONE_DMA
  46. bool
  47. default y
  48. config QUICKLIST
  49. bool
  50. default y
  51. config SBUS
  52. bool
  53. config GENERIC_ISA_DMA
  54. bool
  55. default y
  56. config GENERIC_IOMAP
  57. bool
  58. default y
  59. config GENERIC_BUG
  60. bool
  61. default y
  62. depends on BUG
  63. config GENERIC_HWEIGHT
  64. bool
  65. default y
  66. config ARCH_MAY_HAVE_PC_FDC
  67. bool
  68. default y
  69. config DMI
  70. bool
  71. default y
  72. source "init/Kconfig"
  73. menu "Processor type and features"
  74. source "kernel/time/Kconfig"
  75. config SMP
  76. bool "Symmetric multi-processing support"
  77. ---help---
  78. This enables support for systems with more than one CPU. If you have
  79. a system with only one CPU, like most personal computers, say N. If
  80. you have a system with more than one CPU, say Y.
  81. If you say N here, the kernel will run on single and multiprocessor
  82. machines, but will use only one CPU of a multiprocessor machine. If
  83. you say Y here, the kernel will run on many, but not all,
  84. singleprocessor machines. On a singleprocessor machine, the kernel
  85. will run faster if you say N here.
  86. Note that if you say Y here and choose architecture "586" or
  87. "Pentium" under "Processor family", the kernel will not work on 486
  88. architectures. Similarly, multiprocessor kernels for the "PPro"
  89. architecture may not work on all Pentium based boards.
  90. People using multiprocessor machines who say Y here should also say
  91. Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
  92. Management" code will be disabled if you say Y here.
  93. See also the <file:Documentation/smp.txt>,
  94. <file:Documentation/i386/IO-APIC.txt>,
  95. <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
  96. <http://www.tldp.org/docs.html#howto>.
  97. If you don't know what to do here, say N.
  98. choice
  99. prompt "Subarchitecture Type"
  100. default X86_PC
  101. config X86_PC
  102. bool "PC-compatible"
  103. help
  104. Choose this option if your computer is a standard PC or compatible.
  105. config X86_ELAN
  106. bool "AMD Elan"
  107. depends on X86_32
  108. help
  109. Select this for an AMD Elan processor.
  110. Do not use this option for K6/Athlon/Opteron processors!
  111. If unsure, choose "PC-compatible" instead.
  112. config X86_VOYAGER
  113. bool "Voyager (NCR)"
  114. depends on X86_32
  115. select SMP if !BROKEN
  116. help
  117. Voyager is an MCA-based 32-way capable SMP architecture proprietary
  118. to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
  119. *** WARNING ***
  120. If you do not specifically know you have a Voyager based machine,
  121. say N here, otherwise the kernel you build will not be bootable.
  122. config X86_NUMAQ
  123. bool "NUMAQ (IBM/Sequent)"
  124. select SMP
  125. select NUMA
  126. depends on X86_32
  127. help
  128. This option is used for getting Linux to run on a (IBM/Sequent) NUMA
  129. multiquad box. This changes the way that processors are bootstrapped,
  130. and uses Clustered Logical APIC addressing mode instead of Flat Logical.
  131. You will need a new lynxer.elf file to flash your firmware with - send
  132. email to <Martin.Bligh@us.ibm.com>.
  133. config X86_SUMMIT
  134. bool "Summit/EXA (IBM x440)"
  135. depends on X86_32 && SMP
  136. help
  137. This option is needed for IBM systems that use the Summit/EXA chipset.
  138. In particular, it is needed for the x440.
  139. If you don't have one of these computers, you should say N here.
  140. If you want to build a NUMA kernel, you must select ACPI.
  141. config X86_BIGSMP
  142. bool "Support for other sub-arch SMP systems with more than 8 CPUs"
  143. depends on X86_32 && SMP
  144. help
  145. This option is needed for the systems that have more than 8 CPUs
  146. and if the system is not of any sub-arch type above.
  147. If you don't have such a system, you should say N here.
  148. config X86_VISWS
  149. bool "SGI 320/540 (Visual Workstation)"
  150. depends on X86_32
  151. help
  152. The SGI Visual Workstation series is an IA32-based workstation
  153. based on SGI systems chips with some legacy PC hardware attached.
  154. Say Y here to create a kernel to run on the SGI 320 or 540.
  155. A kernel compiled for the Visual Workstation will not run on PCs
  156. and vice versa. See <file:Documentation/sgi-visws.txt> for details.
  157. config X86_GENERICARCH
  158. bool "Generic architecture (Summit, bigsmp, ES7000, default)"
  159. depends on X86_32
  160. help
  161. This option compiles in the Summit, bigsmp, ES7000, default subarchitectures.
  162. It is intended for a generic binary kernel.
  163. If you want a NUMA kernel, select ACPI. We need SRAT for NUMA.
  164. config X86_ES7000
  165. bool "Support for Unisys ES7000 IA32 series"
  166. depends on X86_32 && SMP
  167. help
  168. Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
  169. supposed to run on an IA32-based Unisys ES7000 system.
  170. Only choose this option if you have such a system, otherwise you
  171. should say N here.
  172. config X86_VSMP
  173. bool "Support for ScaleMP vSMP"
  174. depends on X86_64 && PCI
  175. help
  176. Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
  177. supposed to run on these EM64T-based machines. Only choose this option
  178. if you have one of these machines.
  179. endchoice
  180. config SCHED_NO_NO_OMIT_FRAME_POINTER
  181. bool "Single-depth WCHAN output"
  182. default y
  183. depends on X86_32
  184. help
  185. Calculate simpler /proc/<PID>/wchan values. If this option
  186. is disabled then wchan values will recurse back to the
  187. caller function. This provides more accurate wchan values,
  188. at the expense of slightly more scheduling overhead.
  189. If in doubt, say "Y".
  190. config PARAVIRT
  191. bool
  192. depends on X86_32 && !(X86_VISWS || X86_VOYAGER)
  193. help
  194. This changes the kernel so it can modify itself when it is run
  195. under a hypervisor, potentially improving performance significantly
  196. over full virtualization. However, when run without a hypervisor
  197. the kernel is theoretically slower and slightly larger.
  198. menuconfig PARAVIRT_GUEST
  199. bool "Paravirtualized guest support"
  200. depends on X86_32
  201. help
  202. Say Y here to get to see options related to running Linux under
  203. various hypervisors. This option alone does not add any kernel code.
  204. If you say N, all options in this submenu will be skipped and disabled.
  205. if PARAVIRT_GUEST
  206. source "arch/x86/xen/Kconfig"
  207. config VMI
  208. bool "VMI Guest support"
  209. select PARAVIRT
  210. depends on !(X86_VISWS || X86_VOYAGER)
  211. help
  212. VMI provides a paravirtualized interface to the VMware ESX server
  213. (it could be used by other hypervisors in theory too, but is not
  214. at the moment), by linking the kernel to a GPL-ed ROM module
  215. provided by the hypervisor.
  216. source "arch/x86/lguest/Kconfig"
  217. endif
  218. config ACPI_SRAT
  219. bool
  220. default y
  221. depends on X86_32 && ACPI && NUMA && (X86_SUMMIT || X86_GENERICARCH)
  222. select ACPI_NUMA
  223. config HAVE_ARCH_PARSE_SRAT
  224. bool
  225. default y
  226. depends on ACPI_SRAT
  227. config X86_SUMMIT_NUMA
  228. bool
  229. default y
  230. depends on X86_32 && NUMA && (X86_SUMMIT || X86_GENERICARCH)
  231. config X86_CYCLONE_TIMER
  232. bool
  233. default y
  234. depends on X86_32 && X86_SUMMIT || X86_GENERICARCH
  235. config ES7000_CLUSTERED_APIC
  236. bool
  237. default y
  238. depends on SMP && X86_ES7000 && MPENTIUMIII
  239. source "arch/x86/Kconfig.cpu"
  240. config HPET_TIMER
  241. bool
  242. prompt "HPET Timer Support" if X86_32
  243. default X86_64
  244. help
  245. Use the IA-PC HPET (High Precision Event Timer) to manage
  246. time in preference to the PIT and RTC, if a HPET is
  247. present.
  248. HPET is the next generation timer replacing legacy 8254s.
  249. The HPET provides a stable time base on SMP
  250. systems, unlike the TSC, but it is more expensive to access,
  251. as it is off-chip. You can find the HPET spec at
  252. <http://www.intel.com/hardwaredesign/hpetspec.htm>.
  253. You can safely choose Y here. However, HPET will only be
  254. activated if the platform and the BIOS support this feature.
  255. Otherwise the 8254 will be used for timing services.
  256. Choose N to continue using the legacy 8254 timer.
  257. config HPET_EMULATE_RTC
  258. bool
  259. depends on HPET_TIMER && RTC=y
  260. default y
  261. # Mark as embedded because too many people got it wrong.
  262. # The code disables itself when not needed.
  263. config GART_IOMMU
  264. bool "GART IOMMU support" if EMBEDDED
  265. default y
  266. select SWIOTLB
  267. select AGP
  268. depends on X86_64 && PCI
  269. help
  270. Support for full DMA access of devices with 32bit memory access only
  271. on systems with more than 3GB. This is usually needed for USB,
  272. sound, many IDE/SATA chipsets and some other devices.
  273. Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
  274. based hardware IOMMU and a software bounce buffer based IOMMU used
  275. on Intel systems and as fallback.
  276. The code is only active when needed (enough memory and limited
  277. device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
  278. too.
  279. config CALGARY_IOMMU
  280. bool "IBM Calgary IOMMU support"
  281. select SWIOTLB
  282. depends on X86_64 && PCI && EXPERIMENTAL
  283. help
  284. Support for hardware IOMMUs in IBM's xSeries x366 and x460
  285. systems. Needed to run systems with more than 3GB of memory
  286. properly with 32-bit PCI devices that do not support DAC
  287. (Double Address Cycle). Calgary also supports bus level
  288. isolation, where all DMAs pass through the IOMMU. This
  289. prevents them from going anywhere except their intended
  290. destination. This catches hard-to-find kernel bugs and
  291. mis-behaving drivers and devices that do not use the DMA-API
  292. properly to set up their DMA buffers. The IOMMU can be
  293. turned off at boot time with the iommu=off parameter.
  294. Normally the kernel will make the right choice by itself.
  295. If unsure, say Y.
  296. config CALGARY_IOMMU_ENABLED_BY_DEFAULT
  297. bool "Should Calgary be enabled by default?"
  298. default y
  299. depends on CALGARY_IOMMU
  300. help
  301. Should Calgary be enabled by default? if you choose 'y', Calgary
  302. will be used (if it exists). If you choose 'n', Calgary will not be
  303. used even if it exists. If you choose 'n' and would like to use
  304. Calgary anyway, pass 'iommu=calgary' on the kernel command line.
  305. If unsure, say Y.
  306. # need this always selected by IOMMU for the VIA workaround
  307. config SWIOTLB
  308. bool
  309. help
  310. Support for software bounce buffers used on x86-64 systems
  311. which don't have a hardware IOMMU (e.g. the current generation
  312. of Intel's x86-64 CPUs). Using this PCI devices which can only
  313. access 32-bits of memory can be used on systems with more than
  314. 3 GB of memory. If unsure, say Y.
  315. config NR_CPUS
  316. int "Maximum number of CPUs (2-255)"
  317. range 2 255
  318. depends on SMP
  319. default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
  320. default "8"
  321. help
  322. This allows you to specify the maximum number of CPUs which this
  323. kernel will support. The maximum supported value is 255 and the
  324. minimum value which makes sense is 2.
  325. This is purely to save memory - each supported CPU adds
  326. approximately eight kilobytes to the kernel image.
  327. config SCHED_SMT
  328. bool "SMT (Hyperthreading) scheduler support"
  329. depends on (X86_64 && SMP) || (X86_32 && X86_HT)
  330. help
  331. SMT scheduler support improves the CPU scheduler's decision making
  332. when dealing with Intel Pentium 4 chips with HyperThreading at a
  333. cost of slightly increased overhead in some places. If unsure say
  334. N here.
  335. config SCHED_MC
  336. bool "Multi-core scheduler support"
  337. depends on (X86_64 && SMP) || (X86_32 && X86_HT)
  338. default y
  339. help
  340. Multi-core scheduler support improves the CPU scheduler's decision
  341. making when dealing with multi-core CPU chips at a cost of slightly
  342. increased overhead in some places. If unsure say N here.
  343. source "kernel/Kconfig.preempt"
  344. config X86_UP_APIC
  345. bool "Local APIC support on uniprocessors"
  346. depends on X86_32 && !SMP && !(X86_VISWS || X86_VOYAGER || X86_GENERICARCH)
  347. help
  348. A local APIC (Advanced Programmable Interrupt Controller) is an
  349. integrated interrupt controller in the CPU. If you have a single-CPU
  350. system which has a processor with a local APIC, you can say Y here to
  351. enable and use it. If you say Y here even though your machine doesn't
  352. have a local APIC, then the kernel will still run with no slowdown at
  353. all. The local APIC supports CPU-generated self-interrupts (timer,
  354. performance counters), and the NMI watchdog which detects hard
  355. lockups.
  356. config X86_UP_IOAPIC
  357. bool "IO-APIC support on uniprocessors"
  358. depends on X86_UP_APIC
  359. help
  360. An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
  361. SMP-capable replacement for PC-style interrupt controllers. Most
  362. SMP systems and many recent uniprocessor systems have one.
  363. If you have a single-CPU system with an IO-APIC, you can say Y here
  364. to use it. If you say Y here even though your machine doesn't have
  365. an IO-APIC, then the kernel will still run with no slowdown at all.
  366. config X86_LOCAL_APIC
  367. bool
  368. depends on X86_64 || (X86_32 && (X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER) || X86_GENERICARCH))
  369. default y
  370. config X86_IO_APIC
  371. bool
  372. depends on X86_64 || (X86_32 && (X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER)) || X86_GENERICARCH))
  373. default y
  374. config X86_VISWS_APIC
  375. bool
  376. depends on X86_32 && X86_VISWS
  377. default y
  378. config X86_MCE
  379. bool "Machine Check Exception"
  380. depends on !X86_VOYAGER
  381. ---help---
  382. Machine Check Exception support allows the processor to notify the
  383. kernel if it detects a problem (e.g. overheating, component failure).
  384. The action the kernel takes depends on the severity of the problem,
  385. ranging from a warning message on the console, to halting the machine.
  386. Your processor must be a Pentium or newer to support this - check the
  387. flags in /proc/cpuinfo for mce. Note that some older Pentium systems
  388. have a design flaw which leads to false MCE events - hence MCE is
  389. disabled on all P5 processors, unless explicitly enabled with "mce"
  390. as a boot argument. Similarly, if MCE is built in and creates a
  391. problem on some new non-standard machine, you can boot with "nomce"
  392. to disable it. MCE support simply ignores non-MCE processors like
  393. the 386 and 486, so nearly everyone can say Y here.
  394. config X86_MCE_INTEL
  395. bool "Intel MCE features"
  396. depends on X86_64 && X86_MCE && X86_LOCAL_APIC
  397. default y
  398. help
  399. Additional support for intel specific MCE features such as
  400. the thermal monitor.
  401. config X86_MCE_AMD
  402. bool "AMD MCE features"
  403. depends on X86_64 && X86_MCE && X86_LOCAL_APIC
  404. default y
  405. help
  406. Additional support for AMD specific MCE features such as
  407. the DRAM Error Threshold.
  408. config X86_MCE_NONFATAL
  409. tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
  410. depends on X86_32 && X86_MCE
  411. help
  412. Enabling this feature starts a timer that triggers every 5 seconds which
  413. will look at the machine check registers to see if anything happened.
  414. Non-fatal problems automatically get corrected (but still logged).
  415. Disable this if you don't want to see these messages.
  416. Seeing the messages this option prints out may be indicative of dying
  417. or out-of-spec (ie, overclocked) hardware.
  418. This option only does something on certain CPUs.
  419. (AMD Athlon/Duron and Intel Pentium 4)
  420. config X86_MCE_P4THERMAL
  421. bool "check for P4 thermal throttling interrupt."
  422. depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS
  423. help
  424. Enabling this feature will cause a message to be printed when the P4
  425. enters thermal throttling.
  426. config VM86
  427. bool "Enable VM86 support" if EMBEDDED
  428. default y
  429. depends on X86_32
  430. help
  431. This option is required by programs like DOSEMU to run 16-bit legacy
  432. code on X86 processors. It also may be needed by software like
  433. XFree86 to initialize some video cards via BIOS. Disabling this
  434. option saves about 6k.
  435. config TOSHIBA
  436. tristate "Toshiba Laptop support"
  437. depends on X86_32
  438. ---help---
  439. This adds a driver to safely access the System Management Mode of
  440. the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
  441. not work on models with a Phoenix BIOS. The System Management Mode
  442. is used to set the BIOS and power saving options on Toshiba portables.
  443. For information on utilities to make use of this driver see the
  444. Toshiba Linux utilities web site at:
  445. <http://www.buzzard.org.uk/toshiba/>.
  446. Say Y if you intend to run this kernel on a Toshiba portable.
  447. Say N otherwise.
  448. config I8K
  449. tristate "Dell laptop support"
  450. depends on X86_32
  451. ---help---
  452. This adds a driver to safely access the System Management Mode
  453. of the CPU on the Dell Inspiron 8000. The System Management Mode
  454. is used to read cpu temperature and cooling fan status and to
  455. control the fans on the I8K portables.
  456. This driver has been tested only on the Inspiron 8000 but it may
  457. also work with other Dell laptops. You can force loading on other
  458. models by passing the parameter `force=1' to the module. Use at
  459. your own risk.
  460. For information on utilities to make use of this driver see the
  461. I8K Linux utilities web site at:
  462. <http://people.debian.org/~dz/i8k/>
  463. Say Y if you intend to run this kernel on a Dell Inspiron 8000.
  464. Say N otherwise.
  465. config X86_REBOOTFIXUPS
  466. bool "Enable X86 board specific fixups for reboot"
  467. depends on X86_32 && X86
  468. default n
  469. ---help---
  470. This enables chipset and/or board specific fixups to be done
  471. in order to get reboot to work correctly. This is only needed on
  472. some combinations of hardware and BIOS. The symptom, for which
  473. this config is intended, is when reboot ends with a stalled/hung
  474. system.
  475. Currently, the only fixup is for the Geode machines using
  476. CS5530A and CS5536 chipsets.
  477. Say Y if you want to enable the fixup. Currently, it's safe to
  478. enable this option even if you don't need it.
  479. Say N otherwise.
  480. config MICROCODE
  481. tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
  482. select FW_LOADER
  483. ---help---
  484. If you say Y here, you will be able to update the microcode on
  485. Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
  486. Pentium III, Pentium 4, Xeon etc. You will obviously need the
  487. actual microcode binary data itself which is not shipped with the
  488. Linux kernel.
  489. For latest news and information on obtaining all the required
  490. ingredients for this driver, check:
  491. <http://www.urbanmyth.org/microcode/>.
  492. To compile this driver as a module, choose M here: the
  493. module will be called microcode.
  494. config MICROCODE_OLD_INTERFACE
  495. bool
  496. depends on MICROCODE
  497. default y
  498. config X86_MSR
  499. tristate "/dev/cpu/*/msr - Model-specific register support"
  500. help
  501. This device gives privileged processes access to the x86
  502. Model-Specific Registers (MSRs). It is a character device with
  503. major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
  504. MSR accesses are directed to a specific CPU on multi-processor
  505. systems.
  506. config X86_CPUID
  507. tristate "/dev/cpu/*/cpuid - CPU information support"
  508. help
  509. This device gives processes access to the x86 CPUID instruction to
  510. be executed on a specific processor. It is a character device
  511. with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
  512. /dev/cpu/31/cpuid.
  513. choice
  514. prompt "High Memory Support"
  515. default HIGHMEM4G if !X86_NUMAQ
  516. default HIGHMEM64G if X86_NUMAQ
  517. depends on X86_32
  518. config NOHIGHMEM
  519. bool "off"
  520. depends on !X86_NUMAQ
  521. ---help---
  522. Linux can use up to 64 Gigabytes of physical memory on x86 systems.
  523. However, the address space of 32-bit x86 processors is only 4
  524. Gigabytes large. That means that, if you have a large amount of
  525. physical memory, not all of it can be "permanently mapped" by the
  526. kernel. The physical memory that's not permanently mapped is called
  527. "high memory".
  528. If you are compiling a kernel which will never run on a machine with
  529. more than 1 Gigabyte total physical RAM, answer "off" here (default
  530. choice and suitable for most users). This will result in a "3GB/1GB"
  531. split: 3GB are mapped so that each process sees a 3GB virtual memory
  532. space and the remaining part of the 4GB virtual memory space is used
  533. by the kernel to permanently map as much physical memory as
  534. possible.
  535. If the machine has between 1 and 4 Gigabytes physical RAM, then
  536. answer "4GB" here.
  537. If more than 4 Gigabytes is used then answer "64GB" here. This
  538. selection turns Intel PAE (Physical Address Extension) mode on.
  539. PAE implements 3-level paging on IA32 processors. PAE is fully
  540. supported by Linux, PAE mode is implemented on all recent Intel
  541. processors (Pentium Pro and better). NOTE: If you say "64GB" here,
  542. then the kernel will not boot on CPUs that don't support PAE!
  543. The actual amount of total physical memory will either be
  544. auto detected or can be forced by using a kernel command line option
  545. such as "mem=256M". (Try "man bootparam" or see the documentation of
  546. your boot loader (lilo or loadlin) about how to pass options to the
  547. kernel at boot time.)
  548. If unsure, say "off".
  549. config HIGHMEM4G
  550. bool "4GB"
  551. depends on !X86_NUMAQ
  552. help
  553. Select this if you have a 32-bit processor and between 1 and 4
  554. gigabytes of physical RAM.
  555. config HIGHMEM64G
  556. bool "64GB"
  557. depends on !M386 && !M486
  558. select X86_PAE
  559. help
  560. Select this if you have a 32-bit processor and more than 4
  561. gigabytes of physical RAM.
  562. endchoice
  563. choice
  564. depends on EXPERIMENTAL
  565. prompt "Memory split" if EMBEDDED
  566. default VMSPLIT_3G
  567. depends on X86_32
  568. help
  569. Select the desired split between kernel and user memory.
  570. If the address range available to the kernel is less than the
  571. physical memory installed, the remaining memory will be available
  572. as "high memory". Accessing high memory is a little more costly
  573. than low memory, as it needs to be mapped into the kernel first.
  574. Note that increasing the kernel address space limits the range
  575. available to user programs, making the address space there
  576. tighter. Selecting anything other than the default 3G/1G split
  577. will also likely make your kernel incompatible with binary-only
  578. kernel modules.
  579. If you are not absolutely sure what you are doing, leave this
  580. option alone!
  581. config VMSPLIT_3G
  582. bool "3G/1G user/kernel split"
  583. config VMSPLIT_3G_OPT
  584. depends on !X86_PAE
  585. bool "3G/1G user/kernel split (for full 1G low memory)"
  586. config VMSPLIT_2G
  587. bool "2G/2G user/kernel split"
  588. config VMSPLIT_2G_OPT
  589. depends on !X86_PAE
  590. bool "2G/2G user/kernel split (for full 2G low memory)"
  591. config VMSPLIT_1G
  592. bool "1G/3G user/kernel split"
  593. endchoice
  594. config PAGE_OFFSET
  595. hex
  596. default 0xB0000000 if VMSPLIT_3G_OPT
  597. default 0x80000000 if VMSPLIT_2G
  598. default 0x78000000 if VMSPLIT_2G_OPT
  599. default 0x40000000 if VMSPLIT_1G
  600. default 0xC0000000
  601. depends on X86_32
  602. config HIGHMEM
  603. bool
  604. depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
  605. default y
  606. config X86_PAE
  607. bool "PAE (Physical Address Extension) Support"
  608. default n
  609. depends on X86_32 && !HIGHMEM4G
  610. select RESOURCES_64BIT
  611. help
  612. PAE is required for NX support, and furthermore enables
  613. larger swapspace support for non-overcommit purposes. It
  614. has the cost of more pagetable lookup overhead, and also
  615. consumes more pagetable space per process.
  616. # Common NUMA Features
  617. config NUMA
  618. bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)"
  619. depends on SMP
  620. depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || (X86_SUMMIT || X86_GENERICARCH) && ACPI) && EXPERIMENTAL)
  621. default n if X86_PC
  622. default y if (X86_NUMAQ || X86_SUMMIT)
  623. help
  624. Enable NUMA (Non Uniform Memory Access) support.
  625. The kernel will try to allocate memory used by a CPU on the
  626. local memory controller of the CPU and add some more
  627. NUMA awareness to the kernel.
  628. For i386 this is currently highly experimental and should be only
  629. used for kernel development. It might also cause boot failures.
  630. For x86_64 this is recommended on all multiprocessor Opteron systems.
  631. If the system is EM64T, you should say N unless your system is
  632. EM64T NUMA.
  633. comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
  634. depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
  635. config K8_NUMA
  636. bool "Old style AMD Opteron NUMA detection"
  637. depends on X86_64 && NUMA && PCI
  638. default y
  639. help
  640. Enable K8 NUMA node topology detection. You should say Y here if
  641. you have a multi processor AMD K8 system. This uses an old
  642. method to read the NUMA configuration directly from the builtin
  643. Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
  644. instead, which also takes priority if both are compiled in.
  645. config X86_64_ACPI_NUMA
  646. bool "ACPI NUMA detection"
  647. depends on X86_64 && NUMA && ACPI && PCI
  648. select ACPI_NUMA
  649. default y
  650. help
  651. Enable ACPI SRAT based node topology detection.
  652. config NUMA_EMU
  653. bool "NUMA emulation"
  654. depends on X86_64 && NUMA
  655. help
  656. Enable NUMA emulation. A flat machine will be split
  657. into virtual nodes when booted with "numa=fake=N", where N is the
  658. number of nodes. This is only useful for debugging.
  659. config NODES_SHIFT
  660. int
  661. default "6" if X86_64
  662. default "4" if X86_NUMAQ
  663. default "3"
  664. depends on NEED_MULTIPLE_NODES
  665. config HAVE_ARCH_BOOTMEM_NODE
  666. bool
  667. depends on X86_32 && NUMA
  668. default y
  669. config ARCH_HAVE_MEMORY_PRESENT
  670. bool
  671. depends on X86_32 && DISCONTIGMEM
  672. default y
  673. config NEED_NODE_MEMMAP_SIZE
  674. bool
  675. depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
  676. default y
  677. config HAVE_ARCH_ALLOC_REMAP
  678. bool
  679. depends on X86_32 && NUMA
  680. default y
  681. config ARCH_FLATMEM_ENABLE
  682. def_bool y
  683. depends on (X86_32 && ARCH_SELECT_MEMORY_MODEL && X86_PC) || (X86_64 && !NUMA)
  684. config ARCH_DISCONTIGMEM_ENABLE
  685. def_bool y
  686. depends on NUMA
  687. config ARCH_DISCONTIGMEM_DEFAULT
  688. def_bool y
  689. depends on NUMA
  690. config ARCH_SPARSEMEM_ENABLE
  691. def_bool y
  692. depends on NUMA || (EXPERIMENTAL && (X86_PC || X86_64))
  693. select SPARSEMEM_STATIC if X86_32
  694. select SPARSEMEM_VMEMMAP_ENABLE if X86_64
  695. config ARCH_SELECT_MEMORY_MODEL
  696. def_bool y
  697. depends on X86_32 && ARCH_SPARSEMEM_ENABLE
  698. config ARCH_POPULATES_NODE_MAP
  699. def_bool y
  700. config ARCH_MEMORY_PROBE
  701. def_bool X86_64
  702. depends on MEMORY_HOTPLUG
  703. source "mm/Kconfig"
  704. config HIGHPTE
  705. bool "Allocate 3rd-level pagetables from highmem"
  706. depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
  707. help
  708. The VM uses one page table entry for each page of physical memory.
  709. For systems with a lot of RAM, this can be wasteful of precious
  710. low memory. Setting this option will put user-space page table
  711. entries in high memory.
  712. config MATH_EMULATION
  713. bool
  714. prompt "Math emulation" if X86_32
  715. ---help---
  716. Linux can emulate a math coprocessor (used for floating point
  717. operations) if you don't have one. 486DX and Pentium processors have
  718. a math coprocessor built in, 486SX and 386 do not, unless you added
  719. a 487DX or 387, respectively. (The messages during boot time can
  720. give you some hints here ["man dmesg"].) Everyone needs either a
  721. coprocessor or this emulation.
  722. If you don't have a math coprocessor, you need to say Y here; if you
  723. say Y here even though you have a coprocessor, the coprocessor will
  724. be used nevertheless. (This behavior can be changed with the kernel
  725. command line option "no387", which comes handy if your coprocessor
  726. is broken. Try "man bootparam" or see the documentation of your boot
  727. loader (lilo or loadlin) about how to pass options to the kernel at
  728. boot time.) This means that it is a good idea to say Y here if you
  729. intend to use this kernel on different machines.
  730. More information about the internals of the Linux math coprocessor
  731. emulation can be found in <file:arch/x86/math-emu/README>.
  732. If you are not sure, say Y; apart from resulting in a 66 KB bigger
  733. kernel, it won't hurt.
  734. config MTRR
  735. bool "MTRR (Memory Type Range Register) support"
  736. ---help---
  737. On Intel P6 family processors (Pentium Pro, Pentium II and later)
  738. the Memory Type Range Registers (MTRRs) may be used to control
  739. processor access to memory ranges. This is most useful if you have
  740. a video (VGA) card on a PCI or AGP bus. Enabling write-combining
  741. allows bus write transfers to be combined into a larger transfer
  742. before bursting over the PCI/AGP bus. This can increase performance
  743. of image write operations 2.5 times or more. Saying Y here creates a
  744. /proc/mtrr file which may be used to manipulate your processor's
  745. MTRRs. Typically the X server should use this.
  746. This code has a reasonably generic interface so that similar
  747. control registers on other processors can be easily supported
  748. as well:
  749. The Cyrix 6x86, 6x86MX and M II processors have Address Range
  750. Registers (ARRs) which provide a similar functionality to MTRRs. For
  751. these, the ARRs are used to emulate the MTRRs.
  752. The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
  753. MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
  754. write-combining. All of these processors are supported by this code
  755. and it makes sense to say Y here if you have one of them.
  756. Saying Y here also fixes a problem with buggy SMP BIOSes which only
  757. set the MTRRs for the boot CPU and not for the secondary CPUs. This
  758. can lead to all sorts of problems, so it's good to say Y here.
  759. You can safely say Y even if your machine doesn't have MTRRs, you'll
  760. just add about 9 KB to your kernel.
  761. See <file:Documentation/mtrr.txt> for more information.
  762. config EFI
  763. bool "Boot from EFI support"
  764. depends on X86_32 && ACPI
  765. default n
  766. ---help---
  767. This enables the kernel to boot on EFI platforms using
  768. system configuration information passed to it from the firmware.
  769. This also enables the kernel to use any EFI runtime services that are
  770. available (such as the EFI variable services).
  771. This option is only useful on systems that have EFI firmware
  772. and will result in a kernel image that is ~8k larger. In addition,
  773. you must use the latest ELILO loader available at
  774. <http://elilo.sourceforge.net> in order to take advantage of
  775. kernel initialization using EFI information (neither GRUB nor LILO know
  776. anything about EFI). However, even with this option, the resultant
  777. kernel should continue to boot on existing non-EFI platforms.
  778. config IRQBALANCE
  779. bool "Enable kernel irq balancing"
  780. depends on X86_32 && SMP && X86_IO_APIC
  781. default y
  782. help
  783. The default yes will allow the kernel to do irq load balancing.
  784. Saying no will keep the kernel from doing irq load balancing.
  785. # turning this on wastes a bunch of space.
  786. # Summit needs it only when NUMA is on
  787. config BOOT_IOREMAP
  788. bool
  789. depends on X86_32 && (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI))
  790. default y
  791. config SECCOMP
  792. bool "Enable seccomp to safely compute untrusted bytecode"
  793. depends on PROC_FS
  794. default y
  795. help
  796. This kernel feature is useful for number crunching applications
  797. that may need to compute untrusted bytecode during their
  798. execution. By using pipes or other transports made available to
  799. the process as file descriptors supporting the read/write
  800. syscalls, it's possible to isolate those applications in
  801. their own address space using seccomp. Once seccomp is
  802. enabled via /proc/<pid>/seccomp, it cannot be disabled
  803. and the task is only allowed to execute a few safe syscalls
  804. defined by each seccomp mode.
  805. If unsure, say Y. Only embedded should say N here.
  806. config CC_STACKPROTECTOR
  807. bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
  808. depends on X86_64 && EXPERIMENTAL
  809. help
  810. This option turns on the -fstack-protector GCC feature. This
  811. feature puts, at the beginning of critical functions, a canary
  812. value on the stack just before the return address, and validates
  813. the value just before actually returning. Stack based buffer
  814. overflows (that need to overwrite this return address) now also
  815. overwrite the canary, which gets detected and the attack is then
  816. neutralized via a kernel panic.
  817. This feature requires gcc version 4.2 or above, or a distribution
  818. gcc with the feature backported. Older versions are automatically
  819. detected and for those versions, this configuration option is ignored.
  820. config CC_STACKPROTECTOR_ALL
  821. bool "Use stack-protector for all functions"
  822. depends on CC_STACKPROTECTOR
  823. help
  824. Normally, GCC only inserts the canary value protection for
  825. functions that use large-ish on-stack buffers. By enabling
  826. this option, GCC will be asked to do this for ALL functions.
  827. source kernel/Kconfig.hz
  828. config KEXEC
  829. bool "kexec system call"
  830. help
  831. kexec is a system call that implements the ability to shutdown your
  832. current kernel, and to start another kernel. It is like a reboot
  833. but it is independent of the system firmware. And like a reboot
  834. you can start any kernel with it, not just Linux.
  835. The name comes from the similarity to the exec system call.
  836. It is an ongoing process to be certain the hardware in a machine
  837. is properly shutdown, so do not be surprised if this code does not
  838. initially work for you. It may help to enable device hotplugging
  839. support. As of this writing the exact hardware interface is
  840. strongly in flux, so no good recommendation can be made.
  841. config CRASH_DUMP
  842. bool "kernel crash dumps (EXPERIMENTAL)"
  843. depends on EXPERIMENTAL
  844. depends on X86_64 || (X86_32 && HIGHMEM)
  845. help
  846. Generate crash dump after being started by kexec.
  847. This should be normally only set in special crash dump kernels
  848. which are loaded in the main kernel with kexec-tools into
  849. a specially reserved region and then later executed after
  850. a crash by kdump/kexec. The crash dump kernel must be compiled
  851. to a memory address not used by the main kernel or BIOS using
  852. PHYSICAL_START, or it must be built as a relocatable image
  853. (CONFIG_RELOCATABLE=y).
  854. For more details see Documentation/kdump/kdump.txt
  855. config PHYSICAL_START
  856. hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
  857. default "0x1000000" if X86_NUMAQ
  858. default "0x200000" if X86_64
  859. default "0x100000"
  860. help
  861. This gives the physical address where the kernel is loaded.
  862. If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
  863. bzImage will decompress itself to above physical address and
  864. run from there. Otherwise, bzImage will run from the address where
  865. it has been loaded by the boot loader and will ignore above physical
  866. address.
  867. In normal kdump cases one does not have to set/change this option
  868. as now bzImage can be compiled as a completely relocatable image
  869. (CONFIG_RELOCATABLE=y) and be used to load and run from a different
  870. address. This option is mainly useful for the folks who don't want
  871. to use a bzImage for capturing the crash dump and want to use a
  872. vmlinux instead. vmlinux is not relocatable hence a kernel needs
  873. to be specifically compiled to run from a specific memory area
  874. (normally a reserved region) and this option comes handy.
  875. So if you are using bzImage for capturing the crash dump, leave
  876. the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
  877. Otherwise if you plan to use vmlinux for capturing the crash dump
  878. change this value to start of the reserved region (Typically 16MB
  879. 0x1000000). In other words, it can be set based on the "X" value as
  880. specified in the "crashkernel=YM@XM" command line boot parameter
  881. passed to the panic-ed kernel. Typically this parameter is set as
  882. crashkernel=64M@16M. Please take a look at
  883. Documentation/kdump/kdump.txt for more details about crash dumps.
  884. Usage of bzImage for capturing the crash dump is recommended as
  885. one does not have to build two kernels. Same kernel can be used
  886. as production kernel and capture kernel. Above option should have
  887. gone away after relocatable bzImage support is introduced. But it
  888. is present because there are users out there who continue to use
  889. vmlinux for dump capture. This option should go away down the
  890. line.
  891. Don't change this unless you know what you are doing.
  892. config RELOCATABLE
  893. bool "Build a relocatable kernel (EXPERIMENTAL)"
  894. depends on EXPERIMENTAL
  895. help
  896. This builds a kernel image that retains relocation information
  897. so it can be loaded someplace besides the default 1MB.
  898. The relocations tend to make the kernel binary about 10% larger,
  899. but are discarded at runtime.
  900. One use is for the kexec on panic case where the recovery kernel
  901. must live at a different physical address than the primary
  902. kernel.
  903. Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
  904. it has been loaded at and the compile time physical address
  905. (CONFIG_PHYSICAL_START) is ignored.
  906. config PHYSICAL_ALIGN
  907. hex
  908. prompt "Alignment value to which kernel should be aligned" if X86_32
  909. default "0x100000" if X86_32
  910. default "0x200000" if X86_64
  911. range 0x2000 0x400000
  912. help
  913. This value puts the alignment restrictions on physical address
  914. where kernel is loaded and run from. Kernel is compiled for an
  915. address which meets above alignment restriction.
  916. If bootloader loads the kernel at a non-aligned address and
  917. CONFIG_RELOCATABLE is set, kernel will move itself to nearest
  918. address aligned to above value and run from there.
  919. If bootloader loads the kernel at a non-aligned address and
  920. CONFIG_RELOCATABLE is not set, kernel will ignore the run time
  921. load address and decompress itself to the address it has been
  922. compiled for and run from there. The address for which kernel is
  923. compiled already meets above alignment restrictions. Hence the
  924. end result is that kernel runs from a physical address meeting
  925. above alignment restrictions.
  926. Don't change this unless you know what you are doing.
  927. config HOTPLUG_CPU
  928. bool "Support for suspend on SMP and hot-pluggable CPUs (EXPERIMENTAL)"
  929. depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
  930. ---help---
  931. Say Y here to experiment with turning CPUs off and on, and to
  932. enable suspend on SMP systems. CPUs can be controlled through
  933. /sys/devices/system/cpu.
  934. Say N if you want to disable CPU hotplug and don't need to
  935. suspend.
  936. config COMPAT_VDSO
  937. bool "Compat VDSO support"
  938. default y
  939. depends on X86_32
  940. help
  941. Map the VDSO to the predictable old-style address too.
  942. ---help---
  943. Say N here if you are running a sufficiently recent glibc
  944. version (2.3.3 or later), to remove the high-mapped
  945. VDSO mapping and to exclusively use the randomized VDSO.
  946. If unsure, say Y.
  947. endmenu
  948. config ARCH_ENABLE_MEMORY_HOTPLUG
  949. def_bool y
  950. depends on X86_64 || (X86_32 && HIGHMEM)
  951. config MEMORY_HOTPLUG_RESERVE
  952. def_bool X86_64
  953. depends on (MEMORY_HOTPLUG && DISCONTIGMEM)
  954. config HAVE_ARCH_EARLY_PFN_TO_NID
  955. def_bool X86_64
  956. depends on NUMA
  957. config OUT_OF_LINE_PFN_TO_PAGE
  958. def_bool X86_64
  959. depends on DISCONTIGMEM
  960. #
  961. # Use the generic interrupt handling code in kernel/irq/:
  962. #
  963. config GENERIC_HARDIRQS
  964. bool
  965. default y
  966. config GENERIC_IRQ_PROBE
  967. bool
  968. default y
  969. config GENERIC_PENDING_IRQ
  970. bool
  971. depends on GENERIC_HARDIRQS && SMP
  972. default y
  973. config X86_SMP
  974. bool
  975. depends on X86_32 && SMP && !X86_VOYAGER
  976. default y
  977. config X86_HT
  978. bool
  979. depends on SMP && !(X86_VISWS || X86_VOYAGER || MK8)
  980. default y
  981. config X86_BIOS_REBOOT
  982. bool
  983. depends on X86_32 && !(X86_VISWS || X86_VOYAGER)
  984. default y
  985. config X86_TRAMPOLINE
  986. bool
  987. depends on X86_SMP || (X86_VOYAGER && SMP)
  988. default y
  989. config KTIME_SCALAR
  990. def_bool X86_32
  991. source "arch/x86/Kconfig"