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