Kconfig 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. config GENERIC_TIME
  15. bool
  16. default y
  17. config SEMAPHORE_SLEEPERS
  18. bool
  19. default y
  20. config X86
  21. bool
  22. default y
  23. config MMU
  24. bool
  25. default y
  26. config SBUS
  27. bool
  28. config GENERIC_ISA_DMA
  29. bool
  30. default y
  31. config GENERIC_IOMAP
  32. bool
  33. default y
  34. config GENERIC_HWEIGHT
  35. bool
  36. default y
  37. config ARCH_MAY_HAVE_PC_FDC
  38. bool
  39. default y
  40. config DMI
  41. bool
  42. default y
  43. source "init/Kconfig"
  44. menu "Processor type and features"
  45. config SMP
  46. bool "Symmetric multi-processing support"
  47. ---help---
  48. This enables support for systems with more than one CPU. If you have
  49. a system with only one CPU, like most personal computers, say N. If
  50. you have a system with more than one CPU, say Y.
  51. If you say N here, the kernel will run on single and multiprocessor
  52. machines, but will use only one CPU of a multiprocessor machine. If
  53. you say Y here, the kernel will run on many, but not all,
  54. singleprocessor machines. On a singleprocessor machine, the kernel
  55. will run faster if you say N here.
  56. Note that if you say Y here and choose architecture "586" or
  57. "Pentium" under "Processor family", the kernel will not work on 486
  58. architectures. Similarly, multiprocessor kernels for the "PPro"
  59. architecture may not work on all Pentium based boards.
  60. People using multiprocessor machines who say Y here should also say
  61. Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
  62. Management" code will be disabled if you say Y here.
  63. See also the <file:Documentation/smp.txt>,
  64. <file:Documentation/i386/IO-APIC.txt>,
  65. <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
  66. <http://www.tldp.org/docs.html#howto>.
  67. If you don't know what to do here, say N.
  68. choice
  69. prompt "Subarchitecture Type"
  70. default X86_PC
  71. config X86_PC
  72. bool "PC-compatible"
  73. help
  74. Choose this option if your computer is a standard PC or compatible.
  75. config X86_ELAN
  76. bool "AMD Elan"
  77. help
  78. Select this for an AMD Elan processor.
  79. Do not use this option for K6/Athlon/Opteron processors!
  80. If unsure, choose "PC-compatible" instead.
  81. config X86_VOYAGER
  82. bool "Voyager (NCR)"
  83. help
  84. Voyager is an MCA-based 32-way capable SMP architecture proprietary
  85. to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
  86. *** WARNING ***
  87. If you do not specifically know you have a Voyager based machine,
  88. say N here, otherwise the kernel you build will not be bootable.
  89. config X86_NUMAQ
  90. bool "NUMAQ (IBM/Sequent)"
  91. select SMP
  92. select NUMA
  93. help
  94. This option is used for getting Linux to run on a (IBM/Sequent) NUMA
  95. multiquad box. This changes the way that processors are bootstrapped,
  96. and uses Clustered Logical APIC addressing mode instead of Flat Logical.
  97. You will need a new lynxer.elf file to flash your firmware with - send
  98. email to <Martin.Bligh@us.ibm.com>.
  99. config X86_SUMMIT
  100. bool "Summit/EXA (IBM x440)"
  101. depends on SMP
  102. help
  103. This option is needed for IBM systems that use the Summit/EXA chipset.
  104. In particular, it is needed for the x440.
  105. If you don't have one of these computers, you should say N here.
  106. config X86_BIGSMP
  107. bool "Support for other sub-arch SMP systems with more than 8 CPUs"
  108. depends on SMP
  109. help
  110. This option is needed for the systems that have more than 8 CPUs
  111. and if the system is not of any sub-arch type above.
  112. If you don't have such a system, you should say N here.
  113. config X86_VISWS
  114. bool "SGI 320/540 (Visual Workstation)"
  115. help
  116. The SGI Visual Workstation series is an IA32-based workstation
  117. based on SGI systems chips with some legacy PC hardware attached.
  118. Say Y here to create a kernel to run on the SGI 320 or 540.
  119. A kernel compiled for the Visual Workstation will not run on PCs
  120. and vice versa. See <file:Documentation/sgi-visws.txt> for details.
  121. config X86_GENERICARCH
  122. bool "Generic architecture (Summit, bigsmp, ES7000, default)"
  123. depends on SMP
  124. help
  125. This option compiles in the Summit, bigsmp, ES7000, default subarchitectures.
  126. It is intended for a generic binary kernel.
  127. config X86_ES7000
  128. bool "Support for Unisys ES7000 IA32 series"
  129. depends on SMP
  130. help
  131. Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
  132. supposed to run on an IA32-based Unisys ES7000 system.
  133. Only choose this option if you have such a system, otherwise you
  134. should say N here.
  135. endchoice
  136. config ACPI_SRAT
  137. bool
  138. default y
  139. depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
  140. select ACPI_NUMA
  141. config HAVE_ARCH_PARSE_SRAT
  142. bool
  143. default y
  144. depends on ACPI_SRAT
  145. config X86_SUMMIT_NUMA
  146. bool
  147. default y
  148. depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
  149. config X86_CYCLONE_TIMER
  150. bool
  151. default y
  152. depends on X86_SUMMIT || X86_GENERICARCH
  153. config ES7000_CLUSTERED_APIC
  154. bool
  155. default y
  156. depends on SMP && X86_ES7000 && MPENTIUMIII
  157. source "arch/i386/Kconfig.cpu"
  158. config HPET_TIMER
  159. bool "HPET Timer Support"
  160. help
  161. This enables the use of the HPET for the kernel's internal timer.
  162. HPET is the next generation timer replacing legacy 8254s.
  163. You can safely choose Y here. However, HPET will only be
  164. activated if the platform and the BIOS support this feature.
  165. Otherwise the 8254 will be used for timing services.
  166. Choose N to continue using the legacy 8254 timer.
  167. config HPET_EMULATE_RTC
  168. bool
  169. depends on HPET_TIMER && RTC=y
  170. default y
  171. config NR_CPUS
  172. int "Maximum number of CPUs (2-255)"
  173. range 2 255
  174. depends on SMP
  175. default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
  176. default "8"
  177. help
  178. This allows you to specify the maximum number of CPUs which this
  179. kernel will support. The maximum supported value is 255 and the
  180. minimum value which makes sense is 2.
  181. This is purely to save memory - each supported CPU adds
  182. approximately eight kilobytes to the kernel image.
  183. config SCHED_SMT
  184. bool "SMT (Hyperthreading) scheduler support"
  185. depends on SMP
  186. help
  187. SMT scheduler support improves the CPU scheduler's decision making
  188. when dealing with Intel Pentium 4 chips with HyperThreading at a
  189. cost of slightly increased overhead in some places. If unsure say
  190. N here.
  191. config SCHED_MC
  192. bool "Multi-core scheduler support"
  193. depends on SMP
  194. default y
  195. help
  196. Multi-core scheduler support improves the CPU scheduler's decision
  197. making when dealing with multi-core CPU chips at a cost of slightly
  198. increased overhead in some places. If unsure say N here.
  199. source "kernel/Kconfig.preempt"
  200. config X86_UP_APIC
  201. bool "Local APIC support on uniprocessors"
  202. depends on !SMP && !(X86_VISWS || X86_VOYAGER)
  203. help
  204. A local APIC (Advanced Programmable Interrupt Controller) is an
  205. integrated interrupt controller in the CPU. If you have a single-CPU
  206. system which has a processor with a local APIC, you can say Y here to
  207. enable and use it. If you say Y here even though your machine doesn't
  208. have a local APIC, then the kernel will still run with no slowdown at
  209. all. The local APIC supports CPU-generated self-interrupts (timer,
  210. performance counters), and the NMI watchdog which detects hard
  211. lockups.
  212. config X86_UP_IOAPIC
  213. bool "IO-APIC support on uniprocessors"
  214. depends on X86_UP_APIC
  215. help
  216. An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
  217. SMP-capable replacement for PC-style interrupt controllers. Most
  218. SMP systems and many recent uniprocessor systems have one.
  219. If you have a single-CPU system with an IO-APIC, you can say Y here
  220. to use it. If you say Y here even though your machine doesn't have
  221. an IO-APIC, then the kernel will still run with no slowdown at all.
  222. config X86_LOCAL_APIC
  223. bool
  224. depends on X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER)
  225. default y
  226. config X86_IO_APIC
  227. bool
  228. depends on X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER))
  229. default y
  230. config X86_VISWS_APIC
  231. bool
  232. depends on X86_VISWS
  233. default y
  234. config X86_MCE
  235. bool "Machine Check Exception"
  236. depends on !X86_VOYAGER
  237. ---help---
  238. Machine Check Exception support allows the processor to notify the
  239. kernel if it detects a problem (e.g. overheating, component failure).
  240. The action the kernel takes depends on the severity of the problem,
  241. ranging from a warning message on the console, to halting the machine.
  242. Your processor must be a Pentium or newer to support this - check the
  243. flags in /proc/cpuinfo for mce. Note that some older Pentium systems
  244. have a design flaw which leads to false MCE events - hence MCE is
  245. disabled on all P5 processors, unless explicitly enabled with "mce"
  246. as a boot argument. Similarly, if MCE is built in and creates a
  247. problem on some new non-standard machine, you can boot with "nomce"
  248. to disable it. MCE support simply ignores non-MCE processors like
  249. the 386 and 486, so nearly everyone can say Y here.
  250. config X86_MCE_NONFATAL
  251. tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
  252. depends on X86_MCE
  253. help
  254. Enabling this feature starts a timer that triggers every 5 seconds which
  255. will look at the machine check registers to see if anything happened.
  256. Non-fatal problems automatically get corrected (but still logged).
  257. Disable this if you don't want to see these messages.
  258. Seeing the messages this option prints out may be indicative of dying hardware,
  259. or out-of-spec (ie, overclocked) hardware.
  260. This option only does something on certain CPUs.
  261. (AMD Athlon/Duron and Intel Pentium 4)
  262. config X86_MCE_P4THERMAL
  263. bool "check for P4 thermal throttling interrupt."
  264. depends on X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS
  265. help
  266. Enabling this feature will cause a message to be printed when the P4
  267. enters thermal throttling.
  268. config TOSHIBA
  269. tristate "Toshiba Laptop support"
  270. ---help---
  271. This adds a driver to safely access the System Management Mode of
  272. the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
  273. not work on models with a Phoenix BIOS. The System Management Mode
  274. is used to set the BIOS and power saving options on Toshiba portables.
  275. For information on utilities to make use of this driver see the
  276. Toshiba Linux utilities web site at:
  277. <http://www.buzzard.org.uk/toshiba/>.
  278. Say Y if you intend to run this kernel on a Toshiba portable.
  279. Say N otherwise.
  280. config I8K
  281. tristate "Dell laptop support"
  282. ---help---
  283. This adds a driver to safely access the System Management Mode
  284. of the CPU on the Dell Inspiron 8000. The System Management Mode
  285. is used to read cpu temperature and cooling fan status and to
  286. control the fans on the I8K portables.
  287. This driver has been tested only on the Inspiron 8000 but it may
  288. also work with other Dell laptops. You can force loading on other
  289. models by passing the parameter `force=1' to the module. Use at
  290. your own risk.
  291. For information on utilities to make use of this driver see the
  292. I8K Linux utilities web site at:
  293. <http://people.debian.org/~dz/i8k/>
  294. Say Y if you intend to run this kernel on a Dell Inspiron 8000.
  295. Say N otherwise.
  296. config X86_REBOOTFIXUPS
  297. bool "Enable X86 board specific fixups for reboot"
  298. depends on X86
  299. default n
  300. ---help---
  301. This enables chipset and/or board specific fixups to be done
  302. in order to get reboot to work correctly. This is only needed on
  303. some combinations of hardware and BIOS. The symptom, for which
  304. this config is intended, is when reboot ends with a stalled/hung
  305. system.
  306. Currently, the only fixup is for the Geode GX1/CS5530A/TROM2.1.
  307. combination.
  308. Say Y if you want to enable the fixup. Currently, it's safe to
  309. enable this option even if you don't need it.
  310. Say N otherwise.
  311. config MICROCODE
  312. tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
  313. ---help---
  314. If you say Y here and also to "/dev file system support" in the
  315. 'File systems' section, you will be able to update the microcode on
  316. Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
  317. Pentium III, Pentium 4, Xeon etc. You will obviously need the
  318. actual microcode binary data itself which is not shipped with the
  319. Linux kernel.
  320. For latest news and information on obtaining all the required
  321. ingredients for this driver, check:
  322. <http://www.urbanmyth.org/microcode/>.
  323. To compile this driver as a module, choose M here: the
  324. module will be called microcode.
  325. config X86_MSR
  326. tristate "/dev/cpu/*/msr - Model-specific register support"
  327. help
  328. This device gives privileged processes access to the x86
  329. Model-Specific Registers (MSRs). It is a character device with
  330. major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
  331. MSR accesses are directed to a specific CPU on multi-processor
  332. systems.
  333. config X86_CPUID
  334. tristate "/dev/cpu/*/cpuid - CPU information support"
  335. help
  336. This device gives processes access to the x86 CPUID instruction to
  337. be executed on a specific processor. It is a character device
  338. with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
  339. /dev/cpu/31/cpuid.
  340. source "drivers/firmware/Kconfig"
  341. choice
  342. prompt "High Memory Support"
  343. default NOHIGHMEM
  344. config NOHIGHMEM
  345. bool "off"
  346. depends on !X86_NUMAQ
  347. ---help---
  348. Linux can use up to 64 Gigabytes of physical memory on x86 systems.
  349. However, the address space of 32-bit x86 processors is only 4
  350. Gigabytes large. That means that, if you have a large amount of
  351. physical memory, not all of it can be "permanently mapped" by the
  352. kernel. The physical memory that's not permanently mapped is called
  353. "high memory".
  354. If you are compiling a kernel which will never run on a machine with
  355. more than 1 Gigabyte total physical RAM, answer "off" here (default
  356. choice and suitable for most users). This will result in a "3GB/1GB"
  357. split: 3GB are mapped so that each process sees a 3GB virtual memory
  358. space and the remaining part of the 4GB virtual memory space is used
  359. by the kernel to permanently map as much physical memory as
  360. possible.
  361. If the machine has between 1 and 4 Gigabytes physical RAM, then
  362. answer "4GB" here.
  363. If more than 4 Gigabytes is used then answer "64GB" here. This
  364. selection turns Intel PAE (Physical Address Extension) mode on.
  365. PAE implements 3-level paging on IA32 processors. PAE is fully
  366. supported by Linux, PAE mode is implemented on all recent Intel
  367. processors (Pentium Pro and better). NOTE: If you say "64GB" here,
  368. then the kernel will not boot on CPUs that don't support PAE!
  369. The actual amount of total physical memory will either be
  370. auto detected or can be forced by using a kernel command line option
  371. such as "mem=256M". (Try "man bootparam" or see the documentation of
  372. your boot loader (lilo or loadlin) about how to pass options to the
  373. kernel at boot time.)
  374. If unsure, say "off".
  375. config HIGHMEM4G
  376. bool "4GB"
  377. depends on !X86_NUMAQ
  378. help
  379. Select this if you have a 32-bit processor and between 1 and 4
  380. gigabytes of physical RAM.
  381. config HIGHMEM64G
  382. bool "64GB"
  383. depends on X86_CMPXCHG64
  384. help
  385. Select this if you have a 32-bit processor and more than 4
  386. gigabytes of physical RAM.
  387. endchoice
  388. choice
  389. depends on EXPERIMENTAL && !X86_PAE
  390. prompt "Memory split" if EMBEDDED
  391. default VMSPLIT_3G
  392. help
  393. Select the desired split between kernel and user memory.
  394. If the address range available to the kernel is less than the
  395. physical memory installed, the remaining memory will be available
  396. as "high memory". Accessing high memory is a little more costly
  397. than low memory, as it needs to be mapped into the kernel first.
  398. Note that increasing the kernel address space limits the range
  399. available to user programs, making the address space there
  400. tighter. Selecting anything other than the default 3G/1G split
  401. will also likely make your kernel incompatible with binary-only
  402. kernel modules.
  403. If you are not absolutely sure what you are doing, leave this
  404. option alone!
  405. config VMSPLIT_3G
  406. bool "3G/1G user/kernel split"
  407. config VMSPLIT_3G_OPT
  408. bool "3G/1G user/kernel split (for full 1G low memory)"
  409. config VMSPLIT_2G
  410. bool "2G/2G user/kernel split"
  411. config VMSPLIT_1G
  412. bool "1G/3G user/kernel split"
  413. endchoice
  414. config PAGE_OFFSET
  415. hex
  416. default 0xB0000000 if VMSPLIT_3G_OPT
  417. default 0x78000000 if VMSPLIT_2G
  418. default 0x40000000 if VMSPLIT_1G
  419. default 0xC0000000
  420. config HIGHMEM
  421. bool
  422. depends on HIGHMEM64G || HIGHMEM4G
  423. default y
  424. config X86_PAE
  425. bool
  426. depends on HIGHMEM64G
  427. default y
  428. # Common NUMA Features
  429. config NUMA
  430. bool "Numa Memory Allocation and Scheduler Support"
  431. depends on SMP && HIGHMEM64G && (X86_NUMAQ || X86_GENERICARCH || (X86_SUMMIT && ACPI))
  432. default n if X86_PC
  433. default y if (X86_NUMAQ || X86_SUMMIT)
  434. comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
  435. depends on X86_SUMMIT && (!HIGHMEM64G || !ACPI)
  436. config NODES_SHIFT
  437. int
  438. default "4" if X86_NUMAQ
  439. default "3"
  440. depends on NEED_MULTIPLE_NODES
  441. config HAVE_ARCH_BOOTMEM_NODE
  442. bool
  443. depends on NUMA
  444. default y
  445. config ARCH_HAVE_MEMORY_PRESENT
  446. bool
  447. depends on DISCONTIGMEM
  448. default y
  449. config NEED_NODE_MEMMAP_SIZE
  450. bool
  451. depends on DISCONTIGMEM || SPARSEMEM
  452. default y
  453. config HAVE_ARCH_ALLOC_REMAP
  454. bool
  455. depends on NUMA
  456. default y
  457. config ARCH_FLATMEM_ENABLE
  458. def_bool y
  459. depends on (ARCH_SELECT_MEMORY_MODEL && X86_PC)
  460. config ARCH_DISCONTIGMEM_ENABLE
  461. def_bool y
  462. depends on NUMA
  463. config ARCH_DISCONTIGMEM_DEFAULT
  464. def_bool y
  465. depends on NUMA
  466. config ARCH_SPARSEMEM_ENABLE
  467. def_bool y
  468. depends on (NUMA || (X86_PC && EXPERIMENTAL))
  469. select SPARSEMEM_STATIC
  470. config ARCH_SELECT_MEMORY_MODEL
  471. def_bool y
  472. depends on ARCH_SPARSEMEM_ENABLE
  473. source "mm/Kconfig"
  474. config HAVE_ARCH_EARLY_PFN_TO_NID
  475. bool
  476. default y
  477. depends on NUMA
  478. config HIGHPTE
  479. bool "Allocate 3rd-level pagetables from highmem"
  480. depends on HIGHMEM4G || HIGHMEM64G
  481. help
  482. The VM uses one page table entry for each page of physical memory.
  483. For systems with a lot of RAM, this can be wasteful of precious
  484. low memory. Setting this option will put user-space page table
  485. entries in high memory.
  486. config MATH_EMULATION
  487. bool "Math emulation"
  488. ---help---
  489. Linux can emulate a math coprocessor (used for floating point
  490. operations) if you don't have one. 486DX and Pentium processors have
  491. a math coprocessor built in, 486SX and 386 do not, unless you added
  492. a 487DX or 387, respectively. (The messages during boot time can
  493. give you some hints here ["man dmesg"].) Everyone needs either a
  494. coprocessor or this emulation.
  495. If you don't have a math coprocessor, you need to say Y here; if you
  496. say Y here even though you have a coprocessor, the coprocessor will
  497. be used nevertheless. (This behavior can be changed with the kernel
  498. command line option "no387", which comes handy if your coprocessor
  499. is broken. Try "man bootparam" or see the documentation of your boot
  500. loader (lilo or loadlin) about how to pass options to the kernel at
  501. boot time.) This means that it is a good idea to say Y here if you
  502. intend to use this kernel on different machines.
  503. More information about the internals of the Linux math coprocessor
  504. emulation can be found in <file:arch/i386/math-emu/README>.
  505. If you are not sure, say Y; apart from resulting in a 66 KB bigger
  506. kernel, it won't hurt.
  507. config MTRR
  508. bool "MTRR (Memory Type Range Register) support"
  509. ---help---
  510. On Intel P6 family processors (Pentium Pro, Pentium II and later)
  511. the Memory Type Range Registers (MTRRs) may be used to control
  512. processor access to memory ranges. This is most useful if you have
  513. a video (VGA) card on a PCI or AGP bus. Enabling write-combining
  514. allows bus write transfers to be combined into a larger transfer
  515. before bursting over the PCI/AGP bus. This can increase performance
  516. of image write operations 2.5 times or more. Saying Y here creates a
  517. /proc/mtrr file which may be used to manipulate your processor's
  518. MTRRs. Typically the X server should use this.
  519. This code has a reasonably generic interface so that similar
  520. control registers on other processors can be easily supported
  521. as well:
  522. The Cyrix 6x86, 6x86MX and M II processors have Address Range
  523. Registers (ARRs) which provide a similar functionality to MTRRs. For
  524. these, the ARRs are used to emulate the MTRRs.
  525. The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
  526. MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
  527. write-combining. All of these processors are supported by this code
  528. and it makes sense to say Y here if you have one of them.
  529. Saying Y here also fixes a problem with buggy SMP BIOSes which only
  530. set the MTRRs for the boot CPU and not for the secondary CPUs. This
  531. can lead to all sorts of problems, so it's good to say Y here.
  532. You can safely say Y even if your machine doesn't have MTRRs, you'll
  533. just add about 9 KB to your kernel.
  534. See <file:Documentation/mtrr.txt> for more information.
  535. config EFI
  536. bool "Boot from EFI support (EXPERIMENTAL)"
  537. depends on ACPI
  538. default n
  539. ---help---
  540. This enables the the kernel to boot on EFI platforms using
  541. system configuration information passed to it from the firmware.
  542. This also enables the kernel to use any EFI runtime services that are
  543. available (such as the EFI variable services).
  544. This option is only useful on systems that have EFI firmware
  545. and will result in a kernel image that is ~8k larger. In addition,
  546. you must use the latest ELILO loader available at
  547. <http://elilo.sourceforge.net> in order to take advantage of
  548. kernel initialization using EFI information (neither GRUB nor LILO know
  549. anything about EFI). However, even with this option, the resultant
  550. kernel should continue to boot on existing non-EFI platforms.
  551. config IRQBALANCE
  552. bool "Enable kernel irq balancing"
  553. depends on SMP && X86_IO_APIC
  554. default y
  555. help
  556. The default yes will allow the kernel to do irq load balancing.
  557. Saying no will keep the kernel from doing irq load balancing.
  558. # turning this on wastes a bunch of space.
  559. # Summit needs it only when NUMA is on
  560. config BOOT_IOREMAP
  561. bool
  562. depends on (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI))
  563. default y
  564. config REGPARM
  565. bool "Use register arguments"
  566. default y
  567. help
  568. Compile the kernel with -mregparm=3. This instructs gcc to use
  569. a more efficient function call ABI which passes the first three
  570. arguments of a function call via registers, which results in denser
  571. and faster code.
  572. If this option is disabled, then the default ABI of passing
  573. arguments via the stack is used.
  574. If unsure, say Y.
  575. config SECCOMP
  576. bool "Enable seccomp to safely compute untrusted bytecode"
  577. depends on PROC_FS
  578. default y
  579. help
  580. This kernel feature is useful for number crunching applications
  581. that may need to compute untrusted bytecode during their
  582. execution. By using pipes or other transports made available to
  583. the process as file descriptors supporting the read/write
  584. syscalls, it's possible to isolate those applications in
  585. their own address space using seccomp. Once seccomp is
  586. enabled via /proc/<pid>/seccomp, it cannot be disabled
  587. and the task is only allowed to execute a few safe syscalls
  588. defined by each seccomp mode.
  589. If unsure, say Y. Only embedded should say N here.
  590. source kernel/Kconfig.hz
  591. config KEXEC
  592. bool "kexec system call (EXPERIMENTAL)"
  593. depends on EXPERIMENTAL
  594. help
  595. kexec is a system call that implements the ability to shutdown your
  596. current kernel, and to start another kernel. It is like a reboot
  597. but it is indepedent of the system firmware. And like a reboot
  598. you can start any kernel with it, not just Linux.
  599. The name comes from the similiarity to the exec system call.
  600. It is an ongoing process to be certain the hardware in a machine
  601. is properly shutdown, so do not be surprised if this code does not
  602. initially work for you. It may help to enable device hotplugging
  603. support. As of this writing the exact hardware interface is
  604. strongly in flux, so no good recommendation can be made.
  605. config CRASH_DUMP
  606. bool "kernel crash dumps (EXPERIMENTAL)"
  607. depends on EXPERIMENTAL
  608. depends on HIGHMEM
  609. help
  610. Generate crash dump after being started by kexec.
  611. config PHYSICAL_START
  612. hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
  613. default "0x1000000" if CRASH_DUMP
  614. default "0x100000"
  615. help
  616. This gives the physical address where the kernel is loaded. Normally
  617. for regular kernels this value is 0x100000 (1MB). But in the case
  618. of kexec on panic the fail safe kernel needs to run at a different
  619. address than the panic-ed kernel. This option is used to set the load
  620. address for kernels used to capture crash dump on being kexec'ed
  621. after panic. The default value for crash dump kernels is
  622. 0x1000000 (16MB). This can also be set based on the "X" value as
  623. specified in the "crashkernel=YM@XM" command line boot parameter
  624. passed to the panic-ed kernel. Typically this parameter is set as
  625. crashkernel=64M@16M. Please take a look at
  626. Documentation/kdump/kdump.txt for more details about crash dumps.
  627. Don't change this unless you know what you are doing.
  628. config HOTPLUG_CPU
  629. bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
  630. depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
  631. ---help---
  632. Say Y here to experiment with turning CPUs off and on, and to
  633. enable suspend on SMP systems. CPUs can be controlled through
  634. /sys/devices/system/cpu.
  635. endmenu
  636. menu "Power management options (ACPI, APM)"
  637. depends on !X86_VOYAGER
  638. source kernel/power/Kconfig
  639. source "drivers/acpi/Kconfig"
  640. menu "APM (Advanced Power Management) BIOS Support"
  641. depends on PM && !X86_VISWS
  642. config APM
  643. tristate "APM (Advanced Power Management) BIOS support"
  644. depends on PM
  645. ---help---
  646. APM is a BIOS specification for saving power using several different
  647. techniques. This is mostly useful for battery powered laptops with
  648. APM compliant BIOSes. If you say Y here, the system time will be
  649. reset after a RESUME operation, the /proc/apm device will provide
  650. battery status information, and user-space programs will receive
  651. notification of APM "events" (e.g. battery status change).
  652. If you select "Y" here, you can disable actual use of the APM
  653. BIOS by passing the "apm=off" option to the kernel at boot time.
  654. Note that the APM support is almost completely disabled for
  655. machines with more than one CPU.
  656. In order to use APM, you will need supporting software. For location
  657. and more information, read <file:Documentation/pm.txt> and the
  658. Battery Powered Linux mini-HOWTO, available from
  659. <http://www.tldp.org/docs.html#howto>.
  660. This driver does not spin down disk drives (see the hdparm(8)
  661. manpage ("man 8 hdparm") for that), and it doesn't turn off
  662. VESA-compliant "green" monitors.
  663. This driver does not support the TI 4000M TravelMate and the ACER
  664. 486/DX4/75 because they don't have compliant BIOSes. Many "green"
  665. desktop machines also don't have compliant BIOSes, and this driver
  666. may cause those machines to panic during the boot phase.
  667. Generally, if you don't have a battery in your machine, there isn't
  668. much point in using this driver and you should say N. If you get
  669. random kernel OOPSes or reboots that don't seem to be related to
  670. anything, try disabling/enabling this option (or disabling/enabling
  671. APM in your BIOS).
  672. Some other things you should try when experiencing seemingly random,
  673. "weird" problems:
  674. 1) make sure that you have enough swap space and that it is
  675. enabled.
  676. 2) pass the "no-hlt" option to the kernel
  677. 3) switch on floating point emulation in the kernel and pass
  678. the "no387" option to the kernel
  679. 4) pass the "floppy=nodma" option to the kernel
  680. 5) pass the "mem=4M" option to the kernel (thereby disabling
  681. all but the first 4 MB of RAM)
  682. 6) make sure that the CPU is not over clocked.
  683. 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
  684. 8) disable the cache from your BIOS settings
  685. 9) install a fan for the video card or exchange video RAM
  686. 10) install a better fan for the CPU
  687. 11) exchange RAM chips
  688. 12) exchange the motherboard.
  689. To compile this driver as a module, choose M here: the
  690. module will be called apm.
  691. config APM_IGNORE_USER_SUSPEND
  692. bool "Ignore USER SUSPEND"
  693. depends on APM
  694. help
  695. This option will ignore USER SUSPEND requests. On machines with a
  696. compliant APM BIOS, you want to say N. However, on the NEC Versa M
  697. series notebooks, it is necessary to say Y because of a BIOS bug.
  698. config APM_DO_ENABLE
  699. bool "Enable PM at boot time"
  700. depends on APM
  701. ---help---
  702. Enable APM features at boot time. From page 36 of the APM BIOS
  703. specification: "When disabled, the APM BIOS does not automatically
  704. power manage devices, enter the Standby State, enter the Suspend
  705. State, or take power saving steps in response to CPU Idle calls."
  706. This driver will make CPU Idle calls when Linux is idle (unless this
  707. feature is turned off -- see "Do CPU IDLE calls", below). This
  708. should always save battery power, but more complicated APM features
  709. will be dependent on your BIOS implementation. You may need to turn
  710. this option off if your computer hangs at boot time when using APM
  711. support, or if it beeps continuously instead of suspending. Turn
  712. this off if you have a NEC UltraLite Versa 33/C or a Toshiba
  713. T400CDT. This is off by default since most machines do fine without
  714. this feature.
  715. config APM_CPU_IDLE
  716. bool "Make CPU Idle calls when idle"
  717. depends on APM
  718. help
  719. Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
  720. On some machines, this can activate improved power savings, such as
  721. a slowed CPU clock rate, when the machine is idle. These idle calls
  722. are made after the idle loop has run for some length of time (e.g.,
  723. 333 mS). On some machines, this will cause a hang at boot time or
  724. whenever the CPU becomes idle. (On machines with more than one CPU,
  725. this option does nothing.)
  726. config APM_DISPLAY_BLANK
  727. bool "Enable console blanking using APM"
  728. depends on APM
  729. help
  730. Enable console blanking using the APM. Some laptops can use this to
  731. turn off the LCD backlight when the screen blanker of the Linux
  732. virtual console blanks the screen. Note that this is only used by
  733. the virtual console screen blanker, and won't turn off the backlight
  734. when using the X Window system. This also doesn't have anything to
  735. do with your VESA-compliant power-saving monitor. Further, this
  736. option doesn't work for all laptops -- it might not turn off your
  737. backlight at all, or it might print a lot of errors to the console,
  738. especially if you are using gpm.
  739. config APM_RTC_IS_GMT
  740. bool "RTC stores time in GMT"
  741. depends on APM
  742. help
  743. Say Y here if your RTC (Real Time Clock a.k.a. hardware clock)
  744. stores the time in GMT (Greenwich Mean Time). Say N if your RTC
  745. stores localtime.
  746. It is in fact recommended to store GMT in your RTC, because then you
  747. don't have to worry about daylight savings time changes. The only
  748. reason not to use GMT in your RTC is if you also run a broken OS
  749. that doesn't understand GMT.
  750. config APM_ALLOW_INTS
  751. bool "Allow interrupts during APM BIOS calls"
  752. depends on APM
  753. help
  754. Normally we disable external interrupts while we are making calls to
  755. the APM BIOS as a measure to lessen the effects of a badly behaving
  756. BIOS implementation. The BIOS should reenable interrupts if it
  757. needs to. Unfortunately, some BIOSes do not -- especially those in
  758. many of the newer IBM Thinkpads. If you experience hangs when you
  759. suspend, try setting this to Y. Otherwise, say N.
  760. config APM_REAL_MODE_POWER_OFF
  761. bool "Use real mode APM BIOS call to power off"
  762. depends on APM
  763. help
  764. Use real mode APM BIOS calls to switch off the computer. This is
  765. a work-around for a number of buggy BIOSes. Switch this option on if
  766. your computer crashes instead of powering off properly.
  767. endmenu
  768. source "arch/i386/kernel/cpu/cpufreq/Kconfig"
  769. endmenu
  770. menu "Bus options (PCI, PCMCIA, EISA, MCA, ISA)"
  771. config PCI
  772. bool "PCI support" if !X86_VISWS
  773. depends on !X86_VOYAGER
  774. default y if X86_VISWS
  775. help
  776. Find out whether you have a PCI motherboard. PCI is the name of a
  777. bus system, i.e. the way the CPU talks to the other stuff inside
  778. your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
  779. VESA. If you have PCI, say Y, otherwise N.
  780. The PCI-HOWTO, available from
  781. <http://www.tldp.org/docs.html#howto>, contains valuable
  782. information about which PCI hardware does work under Linux and which
  783. doesn't.
  784. choice
  785. prompt "PCI access mode"
  786. depends on PCI && !X86_VISWS
  787. default PCI_GOANY
  788. ---help---
  789. On PCI systems, the BIOS can be used to detect the PCI devices and
  790. determine their configuration. However, some old PCI motherboards
  791. have BIOS bugs and may crash if this is done. Also, some embedded
  792. PCI-based systems don't have any BIOS at all. Linux can also try to
  793. detect the PCI hardware directly without using the BIOS.
  794. With this option, you can specify how Linux should detect the
  795. PCI devices. If you choose "BIOS", the BIOS will be used,
  796. if you choose "Direct", the BIOS won't be used, and if you
  797. choose "MMConfig", then PCI Express MMCONFIG will be used.
  798. If you choose "Any", the kernel will try MMCONFIG, then the
  799. direct access method and falls back to the BIOS if that doesn't
  800. work. If unsure, go with the default, which is "Any".
  801. config PCI_GOBIOS
  802. bool "BIOS"
  803. config PCI_GOMMCONFIG
  804. bool "MMConfig"
  805. config PCI_GODIRECT
  806. bool "Direct"
  807. config PCI_GOANY
  808. bool "Any"
  809. endchoice
  810. config PCI_BIOS
  811. bool
  812. depends on !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
  813. default y
  814. config PCI_DIRECT
  815. bool
  816. depends on PCI && ((PCI_GODIRECT || PCI_GOANY) || X86_VISWS)
  817. default y
  818. config PCI_MMCONFIG
  819. bool
  820. depends on PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
  821. default y
  822. source "drivers/pci/pcie/Kconfig"
  823. source "drivers/pci/Kconfig"
  824. config ISA_DMA_API
  825. bool
  826. default y
  827. config ISA
  828. bool "ISA support"
  829. depends on !(X86_VOYAGER || X86_VISWS)
  830. help
  831. Find out whether you have ISA slots on your motherboard. ISA is the
  832. name of a bus system, i.e. the way the CPU talks to the other stuff
  833. inside your box. Other bus systems are PCI, EISA, MicroChannel
  834. (MCA) or VESA. ISA is an older system, now being displaced by PCI;
  835. newer boards don't support it. If you have ISA, say Y, otherwise N.
  836. config EISA
  837. bool "EISA support"
  838. depends on ISA
  839. ---help---
  840. The Extended Industry Standard Architecture (EISA) bus was
  841. developed as an open alternative to the IBM MicroChannel bus.
  842. The EISA bus provided some of the features of the IBM MicroChannel
  843. bus while maintaining backward compatibility with cards made for
  844. the older ISA bus. The EISA bus saw limited use between 1988 and
  845. 1995 when it was made obsolete by the PCI bus.
  846. Say Y here if you are building a kernel for an EISA-based machine.
  847. Otherwise, say N.
  848. source "drivers/eisa/Kconfig"
  849. config MCA
  850. bool "MCA support" if !(X86_VISWS || X86_VOYAGER)
  851. default y if X86_VOYAGER
  852. help
  853. MicroChannel Architecture is found in some IBM PS/2 machines and
  854. laptops. It is a bus system similar to PCI or ISA. See
  855. <file:Documentation/mca.txt> (and especially the web page given
  856. there) before attempting to build an MCA bus kernel.
  857. source "drivers/mca/Kconfig"
  858. config SCx200
  859. tristate "NatSemi SCx200 support"
  860. depends on !X86_VOYAGER
  861. help
  862. This provides basic support for the National Semiconductor SCx200
  863. processor. Right now this is just a driver for the GPIO pins.
  864. If you don't know what to do here, say N.
  865. This support is also available as a module. If compiled as a
  866. module, it will be called scx200.
  867. source "drivers/pcmcia/Kconfig"
  868. source "drivers/pci/hotplug/Kconfig"
  869. endmenu
  870. menu "Executable file formats"
  871. source "fs/Kconfig.binfmt"
  872. endmenu
  873. source "net/Kconfig"
  874. source "drivers/Kconfig"
  875. source "fs/Kconfig"
  876. menu "Instrumentation Support"
  877. depends on EXPERIMENTAL
  878. source "arch/i386/oprofile/Kconfig"
  879. config KPROBES
  880. bool "Kprobes (EXPERIMENTAL)"
  881. depends on EXPERIMENTAL && MODULES
  882. help
  883. Kprobes allows you to trap at almost any kernel address and
  884. execute a callback function. register_kprobe() establishes
  885. a probepoint and specifies the callback. Kprobes is useful
  886. for kernel debugging, non-intrusive instrumentation and testing.
  887. If in doubt, say "N".
  888. endmenu
  889. source "arch/i386/Kconfig.debug"
  890. source "security/Kconfig"
  891. source "crypto/Kconfig"
  892. source "lib/Kconfig"
  893. #
  894. # Use the generic interrupt handling code in kernel/irq/:
  895. #
  896. config GENERIC_HARDIRQS
  897. bool
  898. default y
  899. config GENERIC_IRQ_PROBE
  900. bool
  901. default y
  902. config GENERIC_PENDING_IRQ
  903. bool
  904. depends on GENERIC_HARDIRQS && SMP
  905. default y
  906. config X86_SMP
  907. bool
  908. depends on SMP && !X86_VOYAGER
  909. default y
  910. config X86_HT
  911. bool
  912. depends on SMP && !(X86_VISWS || X86_VOYAGER)
  913. default y
  914. config X86_BIOS_REBOOT
  915. bool
  916. depends on !(X86_VISWS || X86_VOYAGER)
  917. default y
  918. config X86_TRAMPOLINE
  919. bool
  920. depends on X86_SMP || (X86_VOYAGER && SMP)
  921. default y
  922. config KTIME_SCALAR
  923. bool
  924. default y