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