Kconfig 38 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 LOCKDEP_SUPPORT
  18. bool
  19. default y
  20. config STACKTRACE_SUPPORT
  21. bool
  22. default y
  23. config SEMAPHORE_SLEEPERS
  24. bool
  25. default y
  26. config X86
  27. bool
  28. default y
  29. config MMU
  30. bool
  31. default y
  32. config SBUS
  33. bool
  34. config GENERIC_ISA_DMA
  35. bool
  36. default y
  37. config GENERIC_IOMAP
  38. bool
  39. default y
  40. config GENERIC_HWEIGHT
  41. bool
  42. default y
  43. config ARCH_MAY_HAVE_PC_FDC
  44. bool
  45. default y
  46. config DMI
  47. bool
  48. default y
  49. source "init/Kconfig"
  50. menu "Processor type and features"
  51. config SMP
  52. bool "Symmetric multi-processing support"
  53. ---help---
  54. This enables support for systems with more than one CPU. If you have
  55. a system with only one CPU, like most personal computers, say N. If
  56. you have a system with more than one CPU, say Y.
  57. If you say N here, the kernel will run on single and multiprocessor
  58. machines, but will use only one CPU of a multiprocessor machine. If
  59. you say Y here, the kernel will run on many, but not all,
  60. singleprocessor machines. On a singleprocessor machine, the kernel
  61. will run faster if you say N here.
  62. Note that if you say Y here and choose architecture "586" or
  63. "Pentium" under "Processor family", the kernel will not work on 486
  64. architectures. Similarly, multiprocessor kernels for the "PPro"
  65. architecture may not work on all Pentium based boards.
  66. People using multiprocessor machines who say Y here should also say
  67. Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
  68. Management" code will be disabled if you say Y here.
  69. See also the <file:Documentation/smp.txt>,
  70. <file:Documentation/i386/IO-APIC.txt>,
  71. <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
  72. <http://www.tldp.org/docs.html#howto>.
  73. If you don't know what to do here, say N.
  74. choice
  75. prompt "Subarchitecture Type"
  76. default X86_PC
  77. config X86_PC
  78. bool "PC-compatible"
  79. help
  80. Choose this option if your computer is a standard PC or compatible.
  81. config X86_ELAN
  82. bool "AMD Elan"
  83. help
  84. Select this for an AMD Elan processor.
  85. Do not use this option for K6/Athlon/Opteron processors!
  86. If unsure, choose "PC-compatible" instead.
  87. config X86_VOYAGER
  88. bool "Voyager (NCR)"
  89. help
  90. Voyager is an MCA-based 32-way capable SMP architecture proprietary
  91. to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
  92. *** WARNING ***
  93. If you do not specifically know you have a Voyager based machine,
  94. say N here, otherwise the kernel you build will not be bootable.
  95. config X86_NUMAQ
  96. bool "NUMAQ (IBM/Sequent)"
  97. select SMP
  98. select NUMA
  99. help
  100. This option is used for getting Linux to run on a (IBM/Sequent) NUMA
  101. multiquad box. This changes the way that processors are bootstrapped,
  102. and uses Clustered Logical APIC addressing mode instead of Flat Logical.
  103. You will need a new lynxer.elf file to flash your firmware with - send
  104. email to <Martin.Bligh@us.ibm.com>.
  105. config X86_SUMMIT
  106. bool "Summit/EXA (IBM x440)"
  107. depends on SMP
  108. help
  109. This option is needed for IBM systems that use the Summit/EXA chipset.
  110. In particular, it is needed for the x440.
  111. If you don't have one of these computers, you should say N here.
  112. config X86_BIGSMP
  113. bool "Support for other sub-arch SMP systems with more than 8 CPUs"
  114. depends on SMP
  115. help
  116. This option is needed for the systems that have more than 8 CPUs
  117. and if the system is not of any sub-arch type above.
  118. If you don't have such a system, you should say N here.
  119. config X86_VISWS
  120. bool "SGI 320/540 (Visual Workstation)"
  121. help
  122. The SGI Visual Workstation series is an IA32-based workstation
  123. based on SGI systems chips with some legacy PC hardware attached.
  124. Say Y here to create a kernel to run on the SGI 320 or 540.
  125. A kernel compiled for the Visual Workstation will not run on PCs
  126. and vice versa. See <file:Documentation/sgi-visws.txt> for details.
  127. config X86_GENERICARCH
  128. bool "Generic architecture (Summit, bigsmp, ES7000, default)"
  129. depends on SMP
  130. help
  131. This option compiles in the Summit, bigsmp, ES7000, default subarchitectures.
  132. It is intended for a generic binary kernel.
  133. config X86_ES7000
  134. bool "Support for Unisys ES7000 IA32 series"
  135. depends on SMP
  136. help
  137. Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
  138. supposed to run on an IA32-based Unisys ES7000 system.
  139. Only choose this option if you have such a system, otherwise you
  140. should say N here.
  141. endchoice
  142. config ACPI_SRAT
  143. bool
  144. default y
  145. depends on ACPI && NUMA && (X86_SUMMIT || X86_GENERICARCH)
  146. select ACPI_NUMA
  147. config HAVE_ARCH_PARSE_SRAT
  148. bool
  149. default y
  150. depends on ACPI_SRAT
  151. config X86_SUMMIT_NUMA
  152. bool
  153. default y
  154. depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
  155. config X86_CYCLONE_TIMER
  156. bool
  157. default y
  158. depends on X86_SUMMIT || X86_GENERICARCH
  159. config ES7000_CLUSTERED_APIC
  160. bool
  161. default y
  162. depends on SMP && X86_ES7000 && MPENTIUMIII
  163. source "arch/i386/Kconfig.cpu"
  164. config HPET_TIMER
  165. bool "HPET Timer Support"
  166. help
  167. This enables the use of the HPET for the kernel's internal timer.
  168. HPET is the next generation timer replacing legacy 8254s.
  169. You can safely choose Y here. However, HPET will only be
  170. activated if the platform and the BIOS support this feature.
  171. Otherwise the 8254 will be used for timing services.
  172. Choose N to continue using the legacy 8254 timer.
  173. config HPET_EMULATE_RTC
  174. bool
  175. depends on HPET_TIMER && RTC=y
  176. default y
  177. config NR_CPUS
  178. int "Maximum number of CPUs (2-255)"
  179. range 2 255
  180. depends on SMP
  181. default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
  182. default "8"
  183. help
  184. This allows you to specify the maximum number of CPUs which this
  185. kernel will support. The maximum supported value is 255 and the
  186. minimum value which makes sense is 2.
  187. This is purely to save memory - each supported CPU adds
  188. approximately eight kilobytes to the kernel image.
  189. config SCHED_SMT
  190. bool "SMT (Hyperthreading) scheduler support"
  191. depends on X86_HT
  192. help
  193. SMT scheduler support improves the CPU scheduler's decision making
  194. when dealing with Intel Pentium 4 chips with HyperThreading at a
  195. cost of slightly increased overhead in some places. If unsure say
  196. N here.
  197. config SCHED_MC
  198. bool "Multi-core scheduler support"
  199. depends on X86_HT
  200. default y
  201. help
  202. Multi-core scheduler support improves the CPU scheduler's decision
  203. making when dealing with multi-core CPU chips at a cost of slightly
  204. increased overhead in some places. If unsure say N here.
  205. source "kernel/Kconfig.preempt"
  206. config X86_UP_APIC
  207. bool "Local APIC support on uniprocessors"
  208. depends on !SMP && !(X86_VISWS || X86_VOYAGER)
  209. help
  210. A local APIC (Advanced Programmable Interrupt Controller) is an
  211. integrated interrupt controller in the CPU. If you have a single-CPU
  212. system which has a processor with a local APIC, you can say Y here to
  213. enable and use it. If you say Y here even though your machine doesn't
  214. have a local APIC, then the kernel will still run with no slowdown at
  215. all. The local APIC supports CPU-generated self-interrupts (timer,
  216. performance counters), and the NMI watchdog which detects hard
  217. lockups.
  218. config X86_UP_IOAPIC
  219. bool "IO-APIC support on uniprocessors"
  220. depends on X86_UP_APIC
  221. help
  222. An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
  223. SMP-capable replacement for PC-style interrupt controllers. Most
  224. SMP systems and many recent uniprocessor systems have one.
  225. If you have a single-CPU system with an IO-APIC, you can say Y here
  226. to use it. If you say Y here even though your machine doesn't have
  227. an IO-APIC, then the kernel will still run with no slowdown at all.
  228. config X86_LOCAL_APIC
  229. bool
  230. depends on X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER)
  231. default y
  232. config X86_IO_APIC
  233. bool
  234. depends on X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER))
  235. default y
  236. config X86_VISWS_APIC
  237. bool
  238. depends on X86_VISWS
  239. default y
  240. config X86_MCE
  241. bool "Machine Check Exception"
  242. depends on !X86_VOYAGER
  243. ---help---
  244. Machine Check Exception support allows the processor to notify the
  245. kernel if it detects a problem (e.g. overheating, component failure).
  246. The action the kernel takes depends on the severity of the problem,
  247. ranging from a warning message on the console, to halting the machine.
  248. Your processor must be a Pentium or newer to support this - check the
  249. flags in /proc/cpuinfo for mce. Note that some older Pentium systems
  250. have a design flaw which leads to false MCE events - hence MCE is
  251. disabled on all P5 processors, unless explicitly enabled with "mce"
  252. as a boot argument. Similarly, if MCE is built in and creates a
  253. problem on some new non-standard machine, you can boot with "nomce"
  254. to disable it. MCE support simply ignores non-MCE processors like
  255. the 386 and 486, so nearly everyone can say Y here.
  256. config X86_MCE_NONFATAL
  257. tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
  258. depends on X86_MCE
  259. help
  260. Enabling this feature starts a timer that triggers every 5 seconds which
  261. will look at the machine check registers to see if anything happened.
  262. Non-fatal problems automatically get corrected (but still logged).
  263. Disable this if you don't want to see these messages.
  264. Seeing the messages this option prints out may be indicative of dying hardware,
  265. or out-of-spec (ie, overclocked) hardware.
  266. This option only does something on certain CPUs.
  267. (AMD Athlon/Duron and Intel Pentium 4)
  268. config X86_MCE_P4THERMAL
  269. bool "check for P4 thermal throttling interrupt."
  270. depends on X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS
  271. help
  272. Enabling this feature will cause a message to be printed when the P4
  273. enters thermal throttling.
  274. config VM86
  275. default y
  276. bool "Enable VM86 support" if EMBEDDED
  277. help
  278. This option is required by programs like DOSEMU to run 16-bit legacy
  279. code on X86 processors. It also may be needed by software like
  280. XFree86 to initialize some video cards via BIOS. Disabling this
  281. option saves about 6k.
  282. config TOSHIBA
  283. tristate "Toshiba Laptop support"
  284. ---help---
  285. This adds a driver to safely access the System Management Mode of
  286. the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
  287. not work on models with a Phoenix BIOS. The System Management Mode
  288. is used to set the BIOS and power saving options on Toshiba portables.
  289. For information on utilities to make use of this driver see the
  290. Toshiba Linux utilities web site at:
  291. <http://www.buzzard.org.uk/toshiba/>.
  292. Say Y if you intend to run this kernel on a Toshiba portable.
  293. Say N otherwise.
  294. config I8K
  295. tristate "Dell laptop support"
  296. ---help---
  297. This adds a driver to safely access the System Management Mode
  298. of the CPU on the Dell Inspiron 8000. The System Management Mode
  299. is used to read cpu temperature and cooling fan status and to
  300. control the fans on the I8K portables.
  301. This driver has been tested only on the Inspiron 8000 but it may
  302. also work with other Dell laptops. You can force loading on other
  303. models by passing the parameter `force=1' to the module. Use at
  304. your own risk.
  305. For information on utilities to make use of this driver see the
  306. I8K Linux utilities web site at:
  307. <http://people.debian.org/~dz/i8k/>
  308. Say Y if you intend to run this kernel on a Dell Inspiron 8000.
  309. Say N otherwise.
  310. config X86_REBOOTFIXUPS
  311. bool "Enable X86 board specific fixups for reboot"
  312. depends on X86
  313. default n
  314. ---help---
  315. This enables chipset and/or board specific fixups to be done
  316. in order to get reboot to work correctly. This is only needed on
  317. some combinations of hardware and BIOS. The symptom, for which
  318. this config is intended, is when reboot ends with a stalled/hung
  319. system.
  320. Currently, the only fixup is for the Geode GX1/CS5530A/TROM2.1.
  321. combination.
  322. Say Y if you want to enable the fixup. Currently, it's safe to
  323. enable this option even if you don't need it.
  324. Say N otherwise.
  325. config MICROCODE
  326. tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
  327. ---help---
  328. If you say Y here and also to "/dev file system support" in the
  329. 'File systems' section, you will be able to update the microcode on
  330. Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
  331. Pentium III, Pentium 4, Xeon etc. You will obviously need the
  332. actual microcode binary data itself which is not shipped with the
  333. Linux kernel.
  334. For latest news and information on obtaining all the required
  335. ingredients for this driver, check:
  336. <http://www.urbanmyth.org/microcode/>.
  337. To compile this driver as a module, choose M here: the
  338. module will be called microcode.
  339. config X86_MSR
  340. tristate "/dev/cpu/*/msr - Model-specific register support"
  341. help
  342. This device gives privileged processes access to the x86
  343. Model-Specific Registers (MSRs). It is a character device with
  344. major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
  345. MSR accesses are directed to a specific CPU on multi-processor
  346. systems.
  347. config X86_CPUID
  348. tristate "/dev/cpu/*/cpuid - CPU information support"
  349. help
  350. This device gives processes access to the x86 CPUID instruction to
  351. be executed on a specific processor. It is a character device
  352. with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
  353. /dev/cpu/31/cpuid.
  354. source "drivers/firmware/Kconfig"
  355. choice
  356. prompt "High Memory Support"
  357. default NOHIGHMEM
  358. config NOHIGHMEM
  359. bool "off"
  360. depends on !X86_NUMAQ
  361. ---help---
  362. Linux can use up to 64 Gigabytes of physical memory on x86 systems.
  363. However, the address space of 32-bit x86 processors is only 4
  364. Gigabytes large. That means that, if you have a large amount of
  365. physical memory, not all of it can be "permanently mapped" by the
  366. kernel. The physical memory that's not permanently mapped is called
  367. "high memory".
  368. If you are compiling a kernel which will never run on a machine with
  369. more than 1 Gigabyte total physical RAM, answer "off" here (default
  370. choice and suitable for most users). This will result in a "3GB/1GB"
  371. split: 3GB are mapped so that each process sees a 3GB virtual memory
  372. space and the remaining part of the 4GB virtual memory space is used
  373. by the kernel to permanently map as much physical memory as
  374. possible.
  375. If the machine has between 1 and 4 Gigabytes physical RAM, then
  376. answer "4GB" here.
  377. If more than 4 Gigabytes is used then answer "64GB" here. This
  378. selection turns Intel PAE (Physical Address Extension) mode on.
  379. PAE implements 3-level paging on IA32 processors. PAE is fully
  380. supported by Linux, PAE mode is implemented on all recent Intel
  381. processors (Pentium Pro and better). NOTE: If you say "64GB" here,
  382. then the kernel will not boot on CPUs that don't support PAE!
  383. The actual amount of total physical memory will either be
  384. auto detected or can be forced by using a kernel command line option
  385. such as "mem=256M". (Try "man bootparam" or see the documentation of
  386. your boot loader (lilo or loadlin) about how to pass options to the
  387. kernel at boot time.)
  388. If unsure, say "off".
  389. config HIGHMEM4G
  390. bool "4GB"
  391. depends on !X86_NUMAQ
  392. help
  393. Select this if you have a 32-bit processor and between 1 and 4
  394. gigabytes of physical RAM.
  395. config HIGHMEM64G
  396. bool "64GB"
  397. depends on X86_CMPXCHG64
  398. help
  399. Select this if you have a 32-bit processor and more than 4
  400. gigabytes of physical RAM.
  401. endchoice
  402. choice
  403. depends on EXPERIMENTAL && !X86_PAE
  404. prompt "Memory split" if EMBEDDED
  405. default VMSPLIT_3G
  406. help
  407. Select the desired split between kernel and user memory.
  408. If the address range available to the kernel is less than the
  409. physical memory installed, the remaining memory will be available
  410. as "high memory". Accessing high memory is a little more costly
  411. than low memory, as it needs to be mapped into the kernel first.
  412. Note that increasing the kernel address space limits the range
  413. available to user programs, making the address space there
  414. tighter. Selecting anything other than the default 3G/1G split
  415. will also likely make your kernel incompatible with binary-only
  416. kernel modules.
  417. If you are not absolutely sure what you are doing, leave this
  418. option alone!
  419. config VMSPLIT_3G
  420. bool "3G/1G user/kernel split"
  421. config VMSPLIT_3G_OPT
  422. bool "3G/1G user/kernel split (for full 1G low memory)"
  423. config VMSPLIT_2G
  424. bool "2G/2G user/kernel split"
  425. config VMSPLIT_1G
  426. bool "1G/3G user/kernel split"
  427. endchoice
  428. config PAGE_OFFSET
  429. hex
  430. default 0xB0000000 if VMSPLIT_3G_OPT
  431. default 0x78000000 if VMSPLIT_2G
  432. default 0x40000000 if VMSPLIT_1G
  433. default 0xC0000000
  434. config HIGHMEM
  435. bool
  436. depends on HIGHMEM64G || HIGHMEM4G
  437. default y
  438. config X86_PAE
  439. bool
  440. depends on HIGHMEM64G
  441. default y
  442. select RESOURCES_64BIT
  443. # Common NUMA Features
  444. config NUMA
  445. bool "Numa Memory Allocation and Scheduler Support"
  446. depends on SMP && HIGHMEM64G && (X86_NUMAQ || X86_GENERICARCH || (X86_SUMMIT && ACPI))
  447. default n if X86_PC
  448. default y if (X86_NUMAQ || X86_SUMMIT)
  449. comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
  450. depends on X86_SUMMIT && (!HIGHMEM64G || !ACPI)
  451. config NODES_SHIFT
  452. int
  453. default "4" if X86_NUMAQ
  454. default "3"
  455. depends on NEED_MULTIPLE_NODES
  456. config HAVE_ARCH_BOOTMEM_NODE
  457. bool
  458. depends on NUMA
  459. default y
  460. config ARCH_HAVE_MEMORY_PRESENT
  461. bool
  462. depends on DISCONTIGMEM
  463. default y
  464. config NEED_NODE_MEMMAP_SIZE
  465. bool
  466. depends on DISCONTIGMEM || SPARSEMEM
  467. default y
  468. config HAVE_ARCH_ALLOC_REMAP
  469. bool
  470. depends on NUMA
  471. default y
  472. config ARCH_FLATMEM_ENABLE
  473. def_bool y
  474. depends on (ARCH_SELECT_MEMORY_MODEL && X86_PC)
  475. config ARCH_DISCONTIGMEM_ENABLE
  476. def_bool y
  477. depends on NUMA
  478. config ARCH_DISCONTIGMEM_DEFAULT
  479. def_bool y
  480. depends on NUMA
  481. config ARCH_SPARSEMEM_ENABLE
  482. def_bool y
  483. depends on (NUMA || (X86_PC && EXPERIMENTAL))
  484. select SPARSEMEM_STATIC
  485. config ARCH_SELECT_MEMORY_MODEL
  486. def_bool y
  487. depends on ARCH_SPARSEMEM_ENABLE
  488. source "mm/Kconfig"
  489. config HAVE_ARCH_EARLY_PFN_TO_NID
  490. bool
  491. default y
  492. depends on NUMA
  493. config HIGHPTE
  494. bool "Allocate 3rd-level pagetables from highmem"
  495. depends on HIGHMEM4G || HIGHMEM64G
  496. help
  497. The VM uses one page table entry for each page of physical memory.
  498. For systems with a lot of RAM, this can be wasteful of precious
  499. low memory. Setting this option will put user-space page table
  500. entries in high memory.
  501. config MATH_EMULATION
  502. bool "Math emulation"
  503. ---help---
  504. Linux can emulate a math coprocessor (used for floating point
  505. operations) if you don't have one. 486DX and Pentium processors have
  506. a math coprocessor built in, 486SX and 386 do not, unless you added
  507. a 487DX or 387, respectively. (The messages during boot time can
  508. give you some hints here ["man dmesg"].) Everyone needs either a
  509. coprocessor or this emulation.
  510. If you don't have a math coprocessor, you need to say Y here; if you
  511. say Y here even though you have a coprocessor, the coprocessor will
  512. be used nevertheless. (This behavior can be changed with the kernel
  513. command line option "no387", which comes handy if your coprocessor
  514. is broken. Try "man bootparam" or see the documentation of your boot
  515. loader (lilo or loadlin) about how to pass options to the kernel at
  516. boot time.) This means that it is a good idea to say Y here if you
  517. intend to use this kernel on different machines.
  518. More information about the internals of the Linux math coprocessor
  519. emulation can be found in <file:arch/i386/math-emu/README>.
  520. If you are not sure, say Y; apart from resulting in a 66 KB bigger
  521. kernel, it won't hurt.
  522. config MTRR
  523. bool "MTRR (Memory Type Range Register) support"
  524. ---help---
  525. On Intel P6 family processors (Pentium Pro, Pentium II and later)
  526. the Memory Type Range Registers (MTRRs) may be used to control
  527. processor access to memory ranges. This is most useful if you have
  528. a video (VGA) card on a PCI or AGP bus. Enabling write-combining
  529. allows bus write transfers to be combined into a larger transfer
  530. before bursting over the PCI/AGP bus. This can increase performance
  531. of image write operations 2.5 times or more. Saying Y here creates a
  532. /proc/mtrr file which may be used to manipulate your processor's
  533. MTRRs. Typically the X server should use this.
  534. This code has a reasonably generic interface so that similar
  535. control registers on other processors can be easily supported
  536. as well:
  537. The Cyrix 6x86, 6x86MX and M II processors have Address Range
  538. Registers (ARRs) which provide a similar functionality to MTRRs. For
  539. these, the ARRs are used to emulate the MTRRs.
  540. The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
  541. MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
  542. write-combining. All of these processors are supported by this code
  543. and it makes sense to say Y here if you have one of them.
  544. Saying Y here also fixes a problem with buggy SMP BIOSes which only
  545. set the MTRRs for the boot CPU and not for the secondary CPUs. This
  546. can lead to all sorts of problems, so it's good to say Y here.
  547. You can safely say Y even if your machine doesn't have MTRRs, you'll
  548. just add about 9 KB to your kernel.
  549. See <file:Documentation/mtrr.txt> for more information.
  550. config EFI
  551. bool "Boot from EFI support (EXPERIMENTAL)"
  552. depends on ACPI
  553. default n
  554. ---help---
  555. This enables the the kernel to boot on EFI platforms using
  556. system configuration information passed to it from the firmware.
  557. This also enables the kernel to use any EFI runtime services that are
  558. available (such as the EFI variable services).
  559. This option is only useful on systems that have EFI firmware
  560. and will result in a kernel image that is ~8k larger. In addition,
  561. you must use the latest ELILO loader available at
  562. <http://elilo.sourceforge.net> in order to take advantage of
  563. kernel initialization using EFI information (neither GRUB nor LILO know
  564. anything about EFI). However, even with this option, the resultant
  565. kernel should continue to boot on existing non-EFI platforms.
  566. config IRQBALANCE
  567. bool "Enable kernel irq balancing"
  568. depends on SMP && X86_IO_APIC
  569. default y
  570. help
  571. The default yes will allow the kernel to do irq load balancing.
  572. Saying no will keep the kernel from doing irq load balancing.
  573. # turning this on wastes a bunch of space.
  574. # Summit needs it only when NUMA is on
  575. config BOOT_IOREMAP
  576. bool
  577. depends on (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI))
  578. default y
  579. config REGPARM
  580. bool "Use register arguments"
  581. default y
  582. help
  583. Compile the kernel with -mregparm=3. This instructs gcc to use
  584. a more efficient function call ABI which passes the first three
  585. arguments of a function call via registers, which results in denser
  586. and faster code.
  587. If this option is disabled, then the default ABI of passing
  588. arguments via the stack is used.
  589. If unsure, say Y.
  590. config SECCOMP
  591. bool "Enable seccomp to safely compute untrusted bytecode"
  592. depends on PROC_FS
  593. default y
  594. help
  595. This kernel feature is useful for number crunching applications
  596. that may need to compute untrusted bytecode during their
  597. execution. By using pipes or other transports made available to
  598. the process as file descriptors supporting the read/write
  599. syscalls, it's possible to isolate those applications in
  600. their own address space using seccomp. Once seccomp is
  601. enabled via /proc/<pid>/seccomp, it cannot be disabled
  602. and the task is only allowed to execute a few safe syscalls
  603. defined by each seccomp mode.
  604. If unsure, say Y. Only embedded should say N here.
  605. source kernel/Kconfig.hz
  606. config KEXEC
  607. bool "kexec system call (EXPERIMENTAL)"
  608. depends on EXPERIMENTAL
  609. help
  610. kexec is a system call that implements the ability to shutdown your
  611. current kernel, and to start another kernel. It is like a reboot
  612. but it is independent of the system firmware. And like a reboot
  613. you can start any kernel with it, not just Linux.
  614. The name comes from the similarity to the exec system call.
  615. It is an ongoing process to be certain the hardware in a machine
  616. is properly shutdown, so do not be surprised if this code does not
  617. initially work for you. It may help to enable device hotplugging
  618. support. As of this writing the exact hardware interface is
  619. strongly in flux, so no good recommendation can be made.
  620. config CRASH_DUMP
  621. bool "kernel crash dumps (EXPERIMENTAL)"
  622. depends on EXPERIMENTAL
  623. depends on HIGHMEM
  624. help
  625. Generate crash dump after being started by kexec.
  626. config PHYSICAL_START
  627. hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
  628. default "0x1000000" if CRASH_DUMP
  629. default "0x100000"
  630. help
  631. This gives the physical address where the kernel is loaded. Normally
  632. for regular kernels this value is 0x100000 (1MB). But in the case
  633. of kexec on panic the fail safe kernel needs to run at a different
  634. address than the panic-ed kernel. This option is used to set the load
  635. address for kernels used to capture crash dump on being kexec'ed
  636. after panic. The default value for crash dump kernels is
  637. 0x1000000 (16MB). This can also be set based on the "X" value as
  638. specified in the "crashkernel=YM@XM" command line boot parameter
  639. passed to the panic-ed kernel. Typically this parameter is set as
  640. crashkernel=64M@16M. Please take a look at
  641. Documentation/kdump/kdump.txt for more details about crash dumps.
  642. Don't change this unless you know what you are doing.
  643. config HOTPLUG_CPU
  644. bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
  645. depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
  646. ---help---
  647. Say Y here to experiment with turning CPUs off and on, and to
  648. enable suspend on SMP systems. CPUs can be controlled through
  649. /sys/devices/system/cpu.
  650. config COMPAT_VDSO
  651. bool "Compat VDSO support"
  652. default y
  653. help
  654. Map the VDSO to the predictable old-style address too.
  655. ---help---
  656. Say N here if you are running a sufficiently recent glibc
  657. version (2.3.3 or later), to remove the high-mapped
  658. VDSO mapping and to exclusively use the randomized VDSO.
  659. If unsure, say Y.
  660. endmenu
  661. config ARCH_ENABLE_MEMORY_HOTPLUG
  662. def_bool y
  663. depends on HIGHMEM
  664. menu "Power management options (ACPI, APM)"
  665. depends on !X86_VOYAGER
  666. source kernel/power/Kconfig
  667. source "drivers/acpi/Kconfig"
  668. menu "APM (Advanced Power Management) BIOS Support"
  669. depends on PM && !X86_VISWS
  670. config APM
  671. tristate "APM (Advanced Power Management) BIOS support"
  672. depends on PM
  673. ---help---
  674. APM is a BIOS specification for saving power using several different
  675. techniques. This is mostly useful for battery powered laptops with
  676. APM compliant BIOSes. If you say Y here, the system time will be
  677. reset after a RESUME operation, the /proc/apm device will provide
  678. battery status information, and user-space programs will receive
  679. notification of APM "events" (e.g. battery status change).
  680. If you select "Y" here, you can disable actual use of the APM
  681. BIOS by passing the "apm=off" option to the kernel at boot time.
  682. Note that the APM support is almost completely disabled for
  683. machines with more than one CPU.
  684. In order to use APM, you will need supporting software. For location
  685. and more information, read <file:Documentation/pm.txt> and the
  686. Battery Powered Linux mini-HOWTO, available from
  687. <http://www.tldp.org/docs.html#howto>.
  688. This driver does not spin down disk drives (see the hdparm(8)
  689. manpage ("man 8 hdparm") for that), and it doesn't turn off
  690. VESA-compliant "green" monitors.
  691. This driver does not support the TI 4000M TravelMate and the ACER
  692. 486/DX4/75 because they don't have compliant BIOSes. Many "green"
  693. desktop machines also don't have compliant BIOSes, and this driver
  694. may cause those machines to panic during the boot phase.
  695. Generally, if you don't have a battery in your machine, there isn't
  696. much point in using this driver and you should say N. If you get
  697. random kernel OOPSes or reboots that don't seem to be related to
  698. anything, try disabling/enabling this option (or disabling/enabling
  699. APM in your BIOS).
  700. Some other things you should try when experiencing seemingly random,
  701. "weird" problems:
  702. 1) make sure that you have enough swap space and that it is
  703. enabled.
  704. 2) pass the "no-hlt" option to the kernel
  705. 3) switch on floating point emulation in the kernel and pass
  706. the "no387" option to the kernel
  707. 4) pass the "floppy=nodma" option to the kernel
  708. 5) pass the "mem=4M" option to the kernel (thereby disabling
  709. all but the first 4 MB of RAM)
  710. 6) make sure that the CPU is not over clocked.
  711. 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
  712. 8) disable the cache from your BIOS settings
  713. 9) install a fan for the video card or exchange video RAM
  714. 10) install a better fan for the CPU
  715. 11) exchange RAM chips
  716. 12) exchange the motherboard.
  717. To compile this driver as a module, choose M here: the
  718. module will be called apm.
  719. config APM_IGNORE_USER_SUSPEND
  720. bool "Ignore USER SUSPEND"
  721. depends on APM
  722. help
  723. This option will ignore USER SUSPEND requests. On machines with a
  724. compliant APM BIOS, you want to say N. However, on the NEC Versa M
  725. series notebooks, it is necessary to say Y because of a BIOS bug.
  726. config APM_DO_ENABLE
  727. bool "Enable PM at boot time"
  728. depends on APM
  729. ---help---
  730. Enable APM features at boot time. From page 36 of the APM BIOS
  731. specification: "When disabled, the APM BIOS does not automatically
  732. power manage devices, enter the Standby State, enter the Suspend
  733. State, or take power saving steps in response to CPU Idle calls."
  734. This driver will make CPU Idle calls when Linux is idle (unless this
  735. feature is turned off -- see "Do CPU IDLE calls", below). This
  736. should always save battery power, but more complicated APM features
  737. will be dependent on your BIOS implementation. You may need to turn
  738. this option off if your computer hangs at boot time when using APM
  739. support, or if it beeps continuously instead of suspending. Turn
  740. this off if you have a NEC UltraLite Versa 33/C or a Toshiba
  741. T400CDT. This is off by default since most machines do fine without
  742. this feature.
  743. config APM_CPU_IDLE
  744. bool "Make CPU Idle calls when idle"
  745. depends on APM
  746. help
  747. Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
  748. On some machines, this can activate improved power savings, such as
  749. a slowed CPU clock rate, when the machine is idle. These idle calls
  750. are made after the idle loop has run for some length of time (e.g.,
  751. 333 mS). On some machines, this will cause a hang at boot time or
  752. whenever the CPU becomes idle. (On machines with more than one CPU,
  753. this option does nothing.)
  754. config APM_DISPLAY_BLANK
  755. bool "Enable console blanking using APM"
  756. depends on APM
  757. help
  758. Enable console blanking using the APM. Some laptops can use this to
  759. turn off the LCD backlight when the screen blanker of the Linux
  760. virtual console blanks the screen. Note that this is only used by
  761. the virtual console screen blanker, and won't turn off the backlight
  762. when using the X Window system. This also doesn't have anything to
  763. do with your VESA-compliant power-saving monitor. Further, this
  764. option doesn't work for all laptops -- it might not turn off your
  765. backlight at all, or it might print a lot of errors to the console,
  766. especially if you are using gpm.
  767. config APM_RTC_IS_GMT
  768. bool "RTC stores time in GMT"
  769. depends on APM
  770. help
  771. Say Y here if your RTC (Real Time Clock a.k.a. hardware clock)
  772. stores the time in GMT (Greenwich Mean Time). Say N if your RTC
  773. stores localtime.
  774. It is in fact recommended to store GMT in your RTC, because then you
  775. don't have to worry about daylight savings time changes. The only
  776. reason not to use GMT in your RTC is if you also run a broken OS
  777. that doesn't understand GMT.
  778. config APM_ALLOW_INTS
  779. bool "Allow interrupts during APM BIOS calls"
  780. depends on APM
  781. help
  782. Normally we disable external interrupts while we are making calls to
  783. the APM BIOS as a measure to lessen the effects of a badly behaving
  784. BIOS implementation. The BIOS should reenable interrupts if it
  785. needs to. Unfortunately, some BIOSes do not -- especially those in
  786. many of the newer IBM Thinkpads. If you experience hangs when you
  787. suspend, try setting this to Y. Otherwise, say N.
  788. config APM_REAL_MODE_POWER_OFF
  789. bool "Use real mode APM BIOS call to power off"
  790. depends on APM
  791. help
  792. Use real mode APM BIOS calls to switch off the computer. This is
  793. a work-around for a number of buggy BIOSes. Switch this option on if
  794. your computer crashes instead of powering off properly.
  795. endmenu
  796. source "arch/i386/kernel/cpu/cpufreq/Kconfig"
  797. endmenu
  798. menu "Bus options (PCI, PCMCIA, EISA, MCA, ISA)"
  799. config PCI
  800. bool "PCI support" if !X86_VISWS
  801. depends on !X86_VOYAGER
  802. default y if X86_VISWS
  803. help
  804. Find out whether you have a PCI motherboard. PCI is the name of a
  805. bus system, i.e. the way the CPU talks to the other stuff inside
  806. your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
  807. VESA. If you have PCI, say Y, otherwise N.
  808. The PCI-HOWTO, available from
  809. <http://www.tldp.org/docs.html#howto>, contains valuable
  810. information about which PCI hardware does work under Linux and which
  811. doesn't.
  812. choice
  813. prompt "PCI access mode"
  814. depends on PCI && !X86_VISWS
  815. default PCI_GOANY
  816. ---help---
  817. On PCI systems, the BIOS can be used to detect the PCI devices and
  818. determine their configuration. However, some old PCI motherboards
  819. have BIOS bugs and may crash if this is done. Also, some embedded
  820. PCI-based systems don't have any BIOS at all. Linux can also try to
  821. detect the PCI hardware directly without using the BIOS.
  822. With this option, you can specify how Linux should detect the
  823. PCI devices. If you choose "BIOS", the BIOS will be used,
  824. if you choose "Direct", the BIOS won't be used, and if you
  825. choose "MMConfig", then PCI Express MMCONFIG will be used.
  826. If you choose "Any", the kernel will try MMCONFIG, then the
  827. direct access method and falls back to the BIOS if that doesn't
  828. work. If unsure, go with the default, which is "Any".
  829. config PCI_GOBIOS
  830. bool "BIOS"
  831. config PCI_GOMMCONFIG
  832. bool "MMConfig"
  833. config PCI_GODIRECT
  834. bool "Direct"
  835. config PCI_GOANY
  836. bool "Any"
  837. endchoice
  838. config PCI_BIOS
  839. bool
  840. depends on !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
  841. default y
  842. config PCI_DIRECT
  843. bool
  844. depends on PCI && ((PCI_GODIRECT || PCI_GOANY) || X86_VISWS)
  845. default y
  846. config PCI_MMCONFIG
  847. bool
  848. depends on PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
  849. default y
  850. source "drivers/pci/pcie/Kconfig"
  851. source "drivers/pci/Kconfig"
  852. config ISA_DMA_API
  853. bool
  854. default y
  855. config ISA
  856. bool "ISA support"
  857. depends on !(X86_VOYAGER || X86_VISWS)
  858. help
  859. Find out whether you have ISA slots on your motherboard. ISA is the
  860. name of a bus system, i.e. the way the CPU talks to the other stuff
  861. inside your box. Other bus systems are PCI, EISA, MicroChannel
  862. (MCA) or VESA. ISA is an older system, now being displaced by PCI;
  863. newer boards don't support it. If you have ISA, say Y, otherwise N.
  864. config EISA
  865. bool "EISA support"
  866. depends on ISA
  867. ---help---
  868. The Extended Industry Standard Architecture (EISA) bus was
  869. developed as an open alternative to the IBM MicroChannel bus.
  870. The EISA bus provided some of the features of the IBM MicroChannel
  871. bus while maintaining backward compatibility with cards made for
  872. the older ISA bus. The EISA bus saw limited use between 1988 and
  873. 1995 when it was made obsolete by the PCI bus.
  874. Say Y here if you are building a kernel for an EISA-based machine.
  875. Otherwise, say N.
  876. source "drivers/eisa/Kconfig"
  877. config MCA
  878. bool "MCA support" if !(X86_VISWS || X86_VOYAGER)
  879. default y if X86_VOYAGER
  880. help
  881. MicroChannel Architecture is found in some IBM PS/2 machines and
  882. laptops. It is a bus system similar to PCI or ISA. See
  883. <file:Documentation/mca.txt> (and especially the web page given
  884. there) before attempting to build an MCA bus kernel.
  885. source "drivers/mca/Kconfig"
  886. config SCx200
  887. tristate "NatSemi SCx200 support"
  888. depends on !X86_VOYAGER
  889. help
  890. This provides basic support for National Semiconductor's
  891. (now AMD's) Geode processors. The driver probes for the
  892. PCI-IDs of several on-chip devices, so its a good dependency
  893. for other scx200_* drivers.
  894. If compiled as a module, the driver is named scx200.
  895. config SCx200HR_TIMER
  896. tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
  897. depends on SCx200 && GENERIC_TIME
  898. default y
  899. help
  900. This driver provides a clocksource built upon the on-chip
  901. 27MHz high-resolution timer. Its also a workaround for
  902. NSC Geode SC-1100's buggy TSC, which loses time when the
  903. processor goes idle (as is done by the scheduler). The
  904. other workaround is idle=poll boot option.
  905. config K8_NB
  906. def_bool y
  907. depends on AGP_AMD64
  908. source "drivers/pcmcia/Kconfig"
  909. source "drivers/pci/hotplug/Kconfig"
  910. endmenu
  911. menu "Executable file formats"
  912. source "fs/Kconfig.binfmt"
  913. endmenu
  914. source "net/Kconfig"
  915. source "drivers/Kconfig"
  916. source "fs/Kconfig"
  917. menu "Instrumentation Support"
  918. depends on EXPERIMENTAL
  919. source "arch/i386/oprofile/Kconfig"
  920. config KPROBES
  921. bool "Kprobes (EXPERIMENTAL)"
  922. depends on EXPERIMENTAL && MODULES
  923. help
  924. Kprobes allows you to trap at almost any kernel address and
  925. execute a callback function. register_kprobe() establishes
  926. a probepoint and specifies the callback. Kprobes is useful
  927. for kernel debugging, non-intrusive instrumentation and testing.
  928. If in doubt, say "N".
  929. endmenu
  930. source "arch/i386/Kconfig.debug"
  931. source "security/Kconfig"
  932. source "crypto/Kconfig"
  933. source "lib/Kconfig"
  934. #
  935. # Use the generic interrupt handling code in kernel/irq/:
  936. #
  937. config GENERIC_HARDIRQS
  938. bool
  939. default y
  940. config GENERIC_IRQ_PROBE
  941. bool
  942. default y
  943. config GENERIC_PENDING_IRQ
  944. bool
  945. depends on GENERIC_HARDIRQS && SMP
  946. default y
  947. config X86_SMP
  948. bool
  949. depends on SMP && !X86_VOYAGER
  950. default y
  951. config X86_HT
  952. bool
  953. depends on SMP && !(X86_VISWS || X86_VOYAGER)
  954. default y
  955. config X86_BIOS_REBOOT
  956. bool
  957. depends on !(X86_VISWS || X86_VOYAGER)
  958. default y
  959. config X86_TRAMPOLINE
  960. bool
  961. depends on X86_SMP || (X86_VOYAGER && SMP)
  962. default y
  963. config KTIME_SCALAR
  964. bool
  965. default y