Kconfig.i386 32 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. endchoice
  173. config SCHED_NO_NO_OMIT_FRAME_POINTER
  174. bool "Single-depth WCHAN output"
  175. default y
  176. depends on X86_32
  177. help
  178. Calculate simpler /proc/<PID>/wchan values. If this option
  179. is disabled then wchan values will recurse back to the
  180. caller function. This provides more accurate wchan values,
  181. at the expense of slightly more scheduling overhead.
  182. If in doubt, say "Y".
  183. config PARAVIRT
  184. bool
  185. depends on X86_32 && !(X86_VISWS || X86_VOYAGER)
  186. help
  187. This changes the kernel so it can modify itself when it is run
  188. under a hypervisor, potentially improving performance significantly
  189. over full virtualization. However, when run without a hypervisor
  190. the kernel is theoretically slower and slightly larger.
  191. menuconfig PARAVIRT_GUEST
  192. bool "Paravirtualized guest support"
  193. depends on X86_32
  194. help
  195. Say Y here to get to see options related to running Linux under
  196. various hypervisors. This option alone does not add any kernel code.
  197. If you say N, all options in this submenu will be skipped and disabled.
  198. if PARAVIRT_GUEST
  199. source "arch/x86/xen/Kconfig"
  200. config VMI
  201. bool "VMI Guest support"
  202. select PARAVIRT
  203. depends on !(X86_VISWS || X86_VOYAGER)
  204. help
  205. VMI provides a paravirtualized interface to the VMware ESX server
  206. (it could be used by other hypervisors in theory too, but is not
  207. at the moment), by linking the kernel to a GPL-ed ROM module
  208. provided by the hypervisor.
  209. source "arch/x86/lguest/Kconfig"
  210. endif
  211. config ACPI_SRAT
  212. bool
  213. default y
  214. depends on X86_32 && ACPI && NUMA && (X86_SUMMIT || X86_GENERICARCH)
  215. select ACPI_NUMA
  216. config HAVE_ARCH_PARSE_SRAT
  217. bool
  218. default y
  219. depends on ACPI_SRAT
  220. config X86_SUMMIT_NUMA
  221. bool
  222. default y
  223. depends on X86_32 && NUMA && (X86_SUMMIT || X86_GENERICARCH)
  224. config X86_CYCLONE_TIMER
  225. bool
  226. default y
  227. depends on X86_32 && X86_SUMMIT || X86_GENERICARCH
  228. config ES7000_CLUSTERED_APIC
  229. bool
  230. default y
  231. depends on SMP && X86_ES7000 && MPENTIUMIII
  232. source "arch/x86/Kconfig.cpu"
  233. config HPET_TIMER
  234. bool
  235. prompt "HPET Timer Support" if X86_32
  236. help
  237. This enables the use of the HPET for the kernel's internal timer.
  238. HPET is the next generation timer replacing legacy 8254s.
  239. You can safely choose Y here. However, HPET will only be
  240. activated if the platform and the BIOS support this feature.
  241. Otherwise the 8254 will be used for timing services.
  242. Choose N to continue using the legacy 8254 timer.
  243. config HPET_EMULATE_RTC
  244. bool
  245. depends on HPET_TIMER && RTC=y
  246. default y
  247. config NR_CPUS
  248. int "Maximum number of CPUs (2-255)"
  249. range 2 255
  250. depends on SMP
  251. default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
  252. default "8"
  253. help
  254. This allows you to specify the maximum number of CPUs which this
  255. kernel will support. The maximum supported value is 255 and the
  256. minimum value which makes sense is 2.
  257. This is purely to save memory - each supported CPU adds
  258. approximately eight kilobytes to the kernel image.
  259. config SCHED_SMT
  260. bool "SMT (Hyperthreading) scheduler support"
  261. depends on X86_HT
  262. help
  263. SMT scheduler support improves the CPU scheduler's decision making
  264. when dealing with Intel Pentium 4 chips with HyperThreading at a
  265. cost of slightly increased overhead in some places. If unsure say
  266. N here.
  267. config SCHED_MC
  268. bool "Multi-core scheduler support"
  269. depends on X86_HT
  270. default y
  271. help
  272. Multi-core scheduler support improves the CPU scheduler's decision
  273. making when dealing with multi-core CPU chips at a cost of slightly
  274. increased overhead in some places. If unsure say N here.
  275. source "kernel/Kconfig.preempt"
  276. config X86_UP_APIC
  277. bool "Local APIC support on uniprocessors"
  278. depends on X86_32 && !SMP && !(X86_VISWS || X86_VOYAGER || X86_GENERICARCH)
  279. help
  280. A local APIC (Advanced Programmable Interrupt Controller) is an
  281. integrated interrupt controller in the CPU. If you have a single-CPU
  282. system which has a processor with a local APIC, you can say Y here to
  283. enable and use it. If you say Y here even though your machine doesn't
  284. have a local APIC, then the kernel will still run with no slowdown at
  285. all. The local APIC supports CPU-generated self-interrupts (timer,
  286. performance counters), and the NMI watchdog which detects hard
  287. lockups.
  288. config X86_UP_IOAPIC
  289. bool "IO-APIC support on uniprocessors"
  290. depends on X86_UP_APIC
  291. help
  292. An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
  293. SMP-capable replacement for PC-style interrupt controllers. Most
  294. SMP systems and many recent uniprocessor systems have one.
  295. If you have a single-CPU system with an IO-APIC, you can say Y here
  296. to use it. If you say Y here even though your machine doesn't have
  297. an IO-APIC, then the kernel will still run with no slowdown at all.
  298. config X86_LOCAL_APIC
  299. bool
  300. depends on X86_32 && (X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER) || X86_GENERICARCH)
  301. default y
  302. config X86_IO_APIC
  303. bool
  304. depends on X86_32 && (X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER)) || X86_GENERICARCH)
  305. default y
  306. config X86_VISWS_APIC
  307. bool
  308. depends on X86_32 && X86_VISWS
  309. default y
  310. config X86_MCE
  311. bool "Machine Check Exception"
  312. depends on !X86_VOYAGER
  313. ---help---
  314. Machine Check Exception support allows the processor to notify the
  315. kernel if it detects a problem (e.g. overheating, component failure).
  316. The action the kernel takes depends on the severity of the problem,
  317. ranging from a warning message on the console, to halting the machine.
  318. Your processor must be a Pentium or newer to support this - check the
  319. flags in /proc/cpuinfo for mce. Note that some older Pentium systems
  320. have a design flaw which leads to false MCE events - hence MCE is
  321. disabled on all P5 processors, unless explicitly enabled with "mce"
  322. as a boot argument. Similarly, if MCE is built in and creates a
  323. problem on some new non-standard machine, you can boot with "nomce"
  324. to disable it. MCE support simply ignores non-MCE processors like
  325. the 386 and 486, so nearly everyone can say Y here.
  326. config X86_MCE_NONFATAL
  327. tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
  328. depends on X86_32 && X86_MCE
  329. help
  330. Enabling this feature starts a timer that triggers every 5 seconds which
  331. will look at the machine check registers to see if anything happened.
  332. Non-fatal problems automatically get corrected (but still logged).
  333. Disable this if you don't want to see these messages.
  334. Seeing the messages this option prints out may be indicative of dying
  335. or out-of-spec (ie, overclocked) hardware.
  336. This option only does something on certain CPUs.
  337. (AMD Athlon/Duron and Intel Pentium 4)
  338. config X86_MCE_P4THERMAL
  339. bool "check for P4 thermal throttling interrupt."
  340. depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS
  341. help
  342. Enabling this feature will cause a message to be printed when the P4
  343. enters thermal throttling.
  344. config VM86
  345. bool "Enable VM86 support" if EMBEDDED
  346. default y
  347. depends on X86_32
  348. help
  349. This option is required by programs like DOSEMU to run 16-bit legacy
  350. code on X86 processors. It also may be needed by software like
  351. XFree86 to initialize some video cards via BIOS. Disabling this
  352. option saves about 6k.
  353. config TOSHIBA
  354. tristate "Toshiba Laptop support"
  355. depends on X86_32
  356. ---help---
  357. This adds a driver to safely access the System Management Mode of
  358. the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
  359. not work on models with a Phoenix BIOS. The System Management Mode
  360. is used to set the BIOS and power saving options on Toshiba portables.
  361. For information on utilities to make use of this driver see the
  362. Toshiba Linux utilities web site at:
  363. <http://www.buzzard.org.uk/toshiba/>.
  364. Say Y if you intend to run this kernel on a Toshiba portable.
  365. Say N otherwise.
  366. config I8K
  367. tristate "Dell laptop support"
  368. depends on X86_32
  369. ---help---
  370. This adds a driver to safely access the System Management Mode
  371. of the CPU on the Dell Inspiron 8000. The System Management Mode
  372. is used to read cpu temperature and cooling fan status and to
  373. control the fans on the I8K portables.
  374. This driver has been tested only on the Inspiron 8000 but it may
  375. also work with other Dell laptops. You can force loading on other
  376. models by passing the parameter `force=1' to the module. Use at
  377. your own risk.
  378. For information on utilities to make use of this driver see the
  379. I8K Linux utilities web site at:
  380. <http://people.debian.org/~dz/i8k/>
  381. Say Y if you intend to run this kernel on a Dell Inspiron 8000.
  382. Say N otherwise.
  383. config X86_REBOOTFIXUPS
  384. bool "Enable X86 board specific fixups for reboot"
  385. depends on X86_32 && X86
  386. default n
  387. ---help---
  388. This enables chipset and/or board specific fixups to be done
  389. in order to get reboot to work correctly. This is only needed on
  390. some combinations of hardware and BIOS. The symptom, for which
  391. this config is intended, is when reboot ends with a stalled/hung
  392. system.
  393. Currently, the only fixup is for the Geode machines using
  394. CS5530A and CS5536 chipsets.
  395. Say Y if you want to enable the fixup. Currently, it's safe to
  396. enable this option even if you don't need it.
  397. Say N otherwise.
  398. config MICROCODE
  399. tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
  400. select FW_LOADER
  401. ---help---
  402. If you say Y here, you will be able to update the microcode on
  403. Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
  404. Pentium III, Pentium 4, Xeon etc. You will obviously need the
  405. actual microcode binary data itself which is not shipped with the
  406. Linux kernel.
  407. For latest news and information on obtaining all the required
  408. ingredients for this driver, check:
  409. <http://www.urbanmyth.org/microcode/>.
  410. To compile this driver as a module, choose M here: the
  411. module will be called microcode.
  412. config MICROCODE_OLD_INTERFACE
  413. bool
  414. depends on MICROCODE
  415. default y
  416. config X86_MSR
  417. tristate "/dev/cpu/*/msr - Model-specific register support"
  418. help
  419. This device gives privileged processes access to the x86
  420. Model-Specific Registers (MSRs). It is a character device with
  421. major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
  422. MSR accesses are directed to a specific CPU on multi-processor
  423. systems.
  424. config X86_CPUID
  425. tristate "/dev/cpu/*/cpuid - CPU information support"
  426. help
  427. This device gives processes access to the x86 CPUID instruction to
  428. be executed on a specific processor. It is a character device
  429. with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
  430. /dev/cpu/31/cpuid.
  431. choice
  432. prompt "High Memory Support"
  433. default HIGHMEM4G if !X86_NUMAQ
  434. default HIGHMEM64G if X86_NUMAQ
  435. depends on X86_32
  436. config NOHIGHMEM
  437. bool "off"
  438. depends on !X86_NUMAQ
  439. ---help---
  440. Linux can use up to 64 Gigabytes of physical memory on x86 systems.
  441. However, the address space of 32-bit x86 processors is only 4
  442. Gigabytes large. That means that, if you have a large amount of
  443. physical memory, not all of it can be "permanently mapped" by the
  444. kernel. The physical memory that's not permanently mapped is called
  445. "high memory".
  446. If you are compiling a kernel which will never run on a machine with
  447. more than 1 Gigabyte total physical RAM, answer "off" here (default
  448. choice and suitable for most users). This will result in a "3GB/1GB"
  449. split: 3GB are mapped so that each process sees a 3GB virtual memory
  450. space and the remaining part of the 4GB virtual memory space is used
  451. by the kernel to permanently map as much physical memory as
  452. possible.
  453. If the machine has between 1 and 4 Gigabytes physical RAM, then
  454. answer "4GB" here.
  455. If more than 4 Gigabytes is used then answer "64GB" here. This
  456. selection turns Intel PAE (Physical Address Extension) mode on.
  457. PAE implements 3-level paging on IA32 processors. PAE is fully
  458. supported by Linux, PAE mode is implemented on all recent Intel
  459. processors (Pentium Pro and better). NOTE: If you say "64GB" here,
  460. then the kernel will not boot on CPUs that don't support PAE!
  461. The actual amount of total physical memory will either be
  462. auto detected or can be forced by using a kernel command line option
  463. such as "mem=256M". (Try "man bootparam" or see the documentation of
  464. your boot loader (lilo or loadlin) about how to pass options to the
  465. kernel at boot time.)
  466. If unsure, say "off".
  467. config HIGHMEM4G
  468. bool "4GB"
  469. depends on !X86_NUMAQ
  470. help
  471. Select this if you have a 32-bit processor and between 1 and 4
  472. gigabytes of physical RAM.
  473. config HIGHMEM64G
  474. bool "64GB"
  475. depends on !M386 && !M486
  476. select X86_PAE
  477. help
  478. Select this if you have a 32-bit processor and more than 4
  479. gigabytes of physical RAM.
  480. endchoice
  481. choice
  482. depends on EXPERIMENTAL
  483. prompt "Memory split" if EMBEDDED
  484. default VMSPLIT_3G
  485. depends on X86_32
  486. help
  487. Select the desired split between kernel and user memory.
  488. If the address range available to the kernel is less than the
  489. physical memory installed, the remaining memory will be available
  490. as "high memory". Accessing high memory is a little more costly
  491. than low memory, as it needs to be mapped into the kernel first.
  492. Note that increasing the kernel address space limits the range
  493. available to user programs, making the address space there
  494. tighter. Selecting anything other than the default 3G/1G split
  495. will also likely make your kernel incompatible with binary-only
  496. kernel modules.
  497. If you are not absolutely sure what you are doing, leave this
  498. option alone!
  499. config VMSPLIT_3G
  500. bool "3G/1G user/kernel split"
  501. config VMSPLIT_3G_OPT
  502. depends on !X86_PAE
  503. bool "3G/1G user/kernel split (for full 1G low memory)"
  504. config VMSPLIT_2G
  505. bool "2G/2G user/kernel split"
  506. config VMSPLIT_2G_OPT
  507. depends on !X86_PAE
  508. bool "2G/2G user/kernel split (for full 2G low memory)"
  509. config VMSPLIT_1G
  510. bool "1G/3G user/kernel split"
  511. endchoice
  512. config PAGE_OFFSET
  513. hex
  514. default 0xB0000000 if VMSPLIT_3G_OPT
  515. default 0x80000000 if VMSPLIT_2G
  516. default 0x78000000 if VMSPLIT_2G_OPT
  517. default 0x40000000 if VMSPLIT_1G
  518. default 0xC0000000
  519. depends on X86_32
  520. config HIGHMEM
  521. bool
  522. depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
  523. default y
  524. config X86_PAE
  525. bool "PAE (Physical Address Extension) Support"
  526. default n
  527. depends on X86_32 && !HIGHMEM4G
  528. select RESOURCES_64BIT
  529. help
  530. PAE is required for NX support, and furthermore enables
  531. larger swapspace support for non-overcommit purposes. It
  532. has the cost of more pagetable lookup overhead, and also
  533. consumes more pagetable space per process.
  534. # Common NUMA Features
  535. config NUMA
  536. bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)"
  537. depends on X86_32 && SMP && HIGHMEM64G && (X86_NUMAQ || (X86_SUMMIT || X86_GENERICARCH) && ACPI) && EXPERIMENTAL
  538. default n if X86_PC
  539. default y if (X86_NUMAQ || X86_SUMMIT)
  540. help
  541. NUMA support for i386. This is currently highly experimental
  542. and should be only used for kernel development. It might also
  543. cause boot failures.
  544. comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
  545. depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
  546. config NODES_SHIFT
  547. int
  548. default "4" if X86_NUMAQ
  549. default "3"
  550. depends on NEED_MULTIPLE_NODES
  551. config HAVE_ARCH_BOOTMEM_NODE
  552. bool
  553. depends on X86_32 && NUMA
  554. default y
  555. config ARCH_HAVE_MEMORY_PRESENT
  556. bool
  557. depends on X86_32 && DISCONTIGMEM
  558. default y
  559. config NEED_NODE_MEMMAP_SIZE
  560. bool
  561. depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
  562. default y
  563. config HAVE_ARCH_ALLOC_REMAP
  564. bool
  565. depends on X86_32 && NUMA
  566. default y
  567. config ARCH_FLATMEM_ENABLE
  568. def_bool y
  569. depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && X86_PC
  570. config ARCH_DISCONTIGMEM_ENABLE
  571. def_bool y
  572. depends on NUMA
  573. config ARCH_DISCONTIGMEM_DEFAULT
  574. def_bool y
  575. depends on NUMA
  576. config ARCH_SPARSEMEM_ENABLE
  577. def_bool y
  578. depends on (NUMA || (X86_PC && EXPERIMENTAL))
  579. select SPARSEMEM_STATIC if X86_32
  580. config ARCH_SELECT_MEMORY_MODEL
  581. def_bool y
  582. depends on X86_32 && ARCH_SPARSEMEM_ENABLE
  583. config ARCH_POPULATES_NODE_MAP
  584. def_bool y
  585. source "mm/Kconfig"
  586. config HIGHPTE
  587. bool "Allocate 3rd-level pagetables from highmem"
  588. depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
  589. help
  590. The VM uses one page table entry for each page of physical memory.
  591. For systems with a lot of RAM, this can be wasteful of precious
  592. low memory. Setting this option will put user-space page table
  593. entries in high memory.
  594. config MATH_EMULATION
  595. bool
  596. prompt "Math emulation" if X86_32
  597. ---help---
  598. Linux can emulate a math coprocessor (used for floating point
  599. operations) if you don't have one. 486DX and Pentium processors have
  600. a math coprocessor built in, 486SX and 386 do not, unless you added
  601. a 487DX or 387, respectively. (The messages during boot time can
  602. give you some hints here ["man dmesg"].) Everyone needs either a
  603. coprocessor or this emulation.
  604. If you don't have a math coprocessor, you need to say Y here; if you
  605. say Y here even though you have a coprocessor, the coprocessor will
  606. be used nevertheless. (This behavior can be changed with the kernel
  607. command line option "no387", which comes handy if your coprocessor
  608. is broken. Try "man bootparam" or see the documentation of your boot
  609. loader (lilo or loadlin) about how to pass options to the kernel at
  610. boot time.) This means that it is a good idea to say Y here if you
  611. intend to use this kernel on different machines.
  612. More information about the internals of the Linux math coprocessor
  613. emulation can be found in <file:arch/x86/math-emu/README>.
  614. If you are not sure, say Y; apart from resulting in a 66 KB bigger
  615. kernel, it won't hurt.
  616. config MTRR
  617. bool "MTRR (Memory Type Range Register) support"
  618. ---help---
  619. On Intel P6 family processors (Pentium Pro, Pentium II and later)
  620. the Memory Type Range Registers (MTRRs) may be used to control
  621. processor access to memory ranges. This is most useful if you have
  622. a video (VGA) card on a PCI or AGP bus. Enabling write-combining
  623. allows bus write transfers to be combined into a larger transfer
  624. before bursting over the PCI/AGP bus. This can increase performance
  625. of image write operations 2.5 times or more. Saying Y here creates a
  626. /proc/mtrr file which may be used to manipulate your processor's
  627. MTRRs. Typically the X server should use this.
  628. This code has a reasonably generic interface so that similar
  629. control registers on other processors can be easily supported
  630. as well:
  631. The Cyrix 6x86, 6x86MX and M II processors have Address Range
  632. Registers (ARRs) which provide a similar functionality to MTRRs. For
  633. these, the ARRs are used to emulate the MTRRs.
  634. The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
  635. MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
  636. write-combining. All of these processors are supported by this code
  637. and it makes sense to say Y here if you have one of them.
  638. Saying Y here also fixes a problem with buggy SMP BIOSes which only
  639. set the MTRRs for the boot CPU and not for the secondary CPUs. This
  640. can lead to all sorts of problems, so it's good to say Y here.
  641. You can safely say Y even if your machine doesn't have MTRRs, you'll
  642. just add about 9 KB to your kernel.
  643. See <file:Documentation/mtrr.txt> for more information.
  644. config EFI
  645. bool "Boot from EFI support"
  646. depends on X86_32 && ACPI
  647. default n
  648. ---help---
  649. This enables the kernel to boot on EFI platforms using
  650. system configuration information passed to it from the firmware.
  651. This also enables the kernel to use any EFI runtime services that are
  652. available (such as the EFI variable services).
  653. This option is only useful on systems that have EFI firmware
  654. and will result in a kernel image that is ~8k larger. In addition,
  655. you must use the latest ELILO loader available at
  656. <http://elilo.sourceforge.net> in order to take advantage of
  657. kernel initialization using EFI information (neither GRUB nor LILO know
  658. anything about EFI). However, even with this option, the resultant
  659. kernel should continue to boot on existing non-EFI platforms.
  660. config IRQBALANCE
  661. bool "Enable kernel irq balancing"
  662. depends on X86_32 && SMP && X86_IO_APIC
  663. default y
  664. help
  665. The default yes will allow the kernel to do irq load balancing.
  666. Saying no will keep the kernel from doing irq load balancing.
  667. # turning this on wastes a bunch of space.
  668. # Summit needs it only when NUMA is on
  669. config BOOT_IOREMAP
  670. bool
  671. depends on X86_32 && (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI))
  672. default y
  673. config SECCOMP
  674. bool "Enable seccomp to safely compute untrusted bytecode"
  675. depends on PROC_FS
  676. default y
  677. help
  678. This kernel feature is useful for number crunching applications
  679. that may need to compute untrusted bytecode during their
  680. execution. By using pipes or other transports made available to
  681. the process as file descriptors supporting the read/write
  682. syscalls, it's possible to isolate those applications in
  683. their own address space using seccomp. Once seccomp is
  684. enabled via /proc/<pid>/seccomp, it cannot be disabled
  685. and the task is only allowed to execute a few safe syscalls
  686. defined by each seccomp mode.
  687. If unsure, say Y. Only embedded should say N here.
  688. source kernel/Kconfig.hz
  689. config KEXEC
  690. bool "kexec system call"
  691. help
  692. kexec is a system call that implements the ability to shutdown your
  693. current kernel, and to start another kernel. It is like a reboot
  694. but it is independent of the system firmware. And like a reboot
  695. you can start any kernel with it, not just Linux.
  696. The name comes from the similarity to the exec system call.
  697. It is an ongoing process to be certain the hardware in a machine
  698. is properly shutdown, so do not be surprised if this code does not
  699. initially work for you. It may help to enable device hotplugging
  700. support. As of this writing the exact hardware interface is
  701. strongly in flux, so no good recommendation can be made.
  702. config CRASH_DUMP
  703. bool "kernel crash dumps (EXPERIMENTAL)"
  704. depends on EXPERIMENTAL
  705. depends on HIGHMEM
  706. help
  707. Generate crash dump after being started by kexec.
  708. This should be normally only set in special crash dump kernels
  709. which are loaded in the main kernel with kexec-tools into
  710. a specially reserved region and then later executed after
  711. a crash by kdump/kexec. The crash dump kernel must be compiled
  712. to a memory address not used by the main kernel or BIOS using
  713. PHYSICAL_START, or it must be built as a relocatable image
  714. (CONFIG_RELOCATABLE=y).
  715. For more details see Documentation/kdump/kdump.txt
  716. config PHYSICAL_START
  717. hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
  718. default "0x1000000" if X86_NUMAQ
  719. default "0x100000"
  720. help
  721. This gives the physical address where the kernel is loaded.
  722. If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
  723. bzImage will decompress itself to above physical address and
  724. run from there. Otherwise, bzImage will run from the address where
  725. it has been loaded by the boot loader and will ignore above physical
  726. address.
  727. In normal kdump cases one does not have to set/change this option
  728. as now bzImage can be compiled as a completely relocatable image
  729. (CONFIG_RELOCATABLE=y) and be used to load and run from a different
  730. address. This option is mainly useful for the folks who don't want
  731. to use a bzImage for capturing the crash dump and want to use a
  732. vmlinux instead. vmlinux is not relocatable hence a kernel needs
  733. to be specifically compiled to run from a specific memory area
  734. (normally a reserved region) and this option comes handy.
  735. So if you are using bzImage for capturing the crash dump, leave
  736. the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
  737. Otherwise if you plan to use vmlinux for capturing the crash dump
  738. change this value to start of the reserved region (Typically 16MB
  739. 0x1000000). In other words, it can be set based on the "X" value as
  740. specified in the "crashkernel=YM@XM" command line boot parameter
  741. passed to the panic-ed kernel. Typically this parameter is set as
  742. crashkernel=64M@16M. Please take a look at
  743. Documentation/kdump/kdump.txt for more details about crash dumps.
  744. Usage of bzImage for capturing the crash dump is recommended as
  745. one does not have to build two kernels. Same kernel can be used
  746. as production kernel and capture kernel. Above option should have
  747. gone away after relocatable bzImage support is introduced. But it
  748. is present because there are users out there who continue to use
  749. vmlinux for dump capture. This option should go away down the
  750. line.
  751. Don't change this unless you know what you are doing.
  752. config RELOCATABLE
  753. bool "Build a relocatable kernel (EXPERIMENTAL)"
  754. depends on EXPERIMENTAL
  755. help
  756. This builds a kernel image that retains relocation information
  757. so it can be loaded someplace besides the default 1MB.
  758. The relocations tend to make the kernel binary about 10% larger,
  759. but are discarded at runtime.
  760. One use is for the kexec on panic case where the recovery kernel
  761. must live at a different physical address than the primary
  762. kernel.
  763. config PHYSICAL_ALIGN
  764. hex
  765. prompt "Alignment value to which kernel should be aligned" if X86_32
  766. default "0x100000"
  767. range 0x2000 0x400000
  768. help
  769. This value puts the alignment restrictions on physical address
  770. where kernel is loaded and run from. Kernel is compiled for an
  771. address which meets above alignment restriction.
  772. If bootloader loads the kernel at a non-aligned address and
  773. CONFIG_RELOCATABLE is set, kernel will move itself to nearest
  774. address aligned to above value and run from there.
  775. If bootloader loads the kernel at a non-aligned address and
  776. CONFIG_RELOCATABLE is not set, kernel will ignore the run time
  777. load address and decompress itself to the address it has been
  778. compiled for and run from there. The address for which kernel is
  779. compiled already meets above alignment restrictions. Hence the
  780. end result is that kernel runs from a physical address meeting
  781. above alignment restrictions.
  782. Don't change this unless you know what you are doing.
  783. config HOTPLUG_CPU
  784. bool "Support for suspend on SMP and hot-pluggable CPUs (EXPERIMENTAL)"
  785. depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
  786. ---help---
  787. Say Y here to experiment with turning CPUs off and on, and to
  788. enable suspend on SMP systems. CPUs can be controlled through
  789. /sys/devices/system/cpu.
  790. config COMPAT_VDSO
  791. bool "Compat VDSO support"
  792. default y
  793. depends on X86_32
  794. help
  795. Map the VDSO to the predictable old-style address too.
  796. ---help---
  797. Say N here if you are running a sufficiently recent glibc
  798. version (2.3.3 or later), to remove the high-mapped
  799. VDSO mapping and to exclusively use the randomized VDSO.
  800. If unsure, say Y.
  801. endmenu
  802. config ARCH_ENABLE_MEMORY_HOTPLUG
  803. def_bool y
  804. depends on HIGHMEM
  805. #
  806. # Use the generic interrupt handling code in kernel/irq/:
  807. #
  808. config GENERIC_HARDIRQS
  809. bool
  810. default y
  811. config GENERIC_IRQ_PROBE
  812. bool
  813. default y
  814. config GENERIC_PENDING_IRQ
  815. bool
  816. depends on GENERIC_HARDIRQS && SMP
  817. default y
  818. config X86_SMP
  819. bool
  820. depends on X86_32 && SMP && !X86_VOYAGER
  821. default y
  822. config X86_HT
  823. bool
  824. depends on SMP && !(X86_VISWS || X86_VOYAGER)
  825. default y
  826. config X86_BIOS_REBOOT
  827. bool
  828. depends on X86_32 && !(X86_VISWS || X86_VOYAGER)
  829. default y
  830. config X86_TRAMPOLINE
  831. bool
  832. depends on X86_SMP || (X86_VOYAGER && SMP)
  833. default y
  834. config KTIME_SCALAR
  835. def_bool X86_32
  836. source "arch/x86/Kconfig"