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