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