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