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