Kconfig 20 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578
  1. config DEFCONFIG_LIST
  2. string
  3. depends on !UML
  4. option defconfig_list
  5. default "/lib/modules/$UNAME_RELEASE/.config"
  6. default "/etc/kernel-config"
  7. default "/boot/config-$UNAME_RELEASE"
  8. default "arch/$ARCH/defconfig"
  9. menu "Code maturity level options"
  10. config EXPERIMENTAL
  11. bool "Prompt for development and/or incomplete code/drivers"
  12. ---help---
  13. Some of the various things that Linux supports (such as network
  14. drivers, file systems, network protocols, etc.) can be in a state
  15. of development where the functionality, stability, or the level of
  16. testing is not yet high enough for general use. This is usually
  17. known as the "alpha-test" phase among developers. If a feature is
  18. currently in alpha-test, then the developers usually discourage
  19. uninformed widespread use of this feature by the general public to
  20. avoid "Why doesn't this work?" type mail messages. However, active
  21. testing and use of these systems is welcomed. Just be aware that it
  22. may not meet the normal level of reliability or it may fail to work
  23. in some special cases. Detailed bug reports from people familiar
  24. with the kernel internals are usually welcomed by the developers
  25. (before submitting bug reports, please read the documents
  26. <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
  27. <file:Documentation/BUG-HUNTING>, and
  28. <file:Documentation/oops-tracing.txt> in the kernel source).
  29. This option will also make obsoleted drivers available. These are
  30. drivers that have been replaced by something else, and/or are
  31. scheduled to be removed in a future kernel release.
  32. Unless you intend to help test and develop a feature or driver that
  33. falls into this category, or you have a situation that requires
  34. using these features, you should probably say N here, which will
  35. cause the configurator to present you with fewer choices. If
  36. you say Y here, you will be offered the choice of using features or
  37. drivers that are currently considered to be in the alpha-test phase.
  38. config BROKEN
  39. bool
  40. config BROKEN_ON_SMP
  41. bool
  42. depends on BROKEN || !SMP
  43. default y
  44. config LOCK_KERNEL
  45. bool
  46. depends on SMP || PREEMPT
  47. default y
  48. config INIT_ENV_ARG_LIMIT
  49. int
  50. default 32 if !UML
  51. default 128 if UML
  52. help
  53. Maximum of each of the number of arguments and environment
  54. variables passed to init from the kernel command line.
  55. endmenu
  56. menu "General setup"
  57. config LOCALVERSION
  58. string "Local version - append to kernel release"
  59. help
  60. Append an extra string to the end of your kernel version.
  61. This will show up when you type uname, for example.
  62. The string you set here will be appended after the contents of
  63. any files with a filename matching localversion* in your
  64. object and source tree, in that order. Your total string can
  65. be a maximum of 64 characters.
  66. config LOCALVERSION_AUTO
  67. bool "Automatically append version information to the version string"
  68. default y
  69. help
  70. This will try to automatically determine if the current tree is a
  71. release tree by looking for git tags that
  72. belong to the current top of tree revision.
  73. A string of the format -gxxxxxxxx will be added to the localversion
  74. if a git based tree is found. The string generated by this will be
  75. appended after any matching localversion* files, and after the value
  76. set in CONFIG_LOCALVERSION
  77. Note: This requires Perl, and a git repository, but not necessarily
  78. the git or cogito tools to be installed.
  79. config SWAP
  80. bool "Support for paging of anonymous memory (swap)"
  81. depends on MMU && BLOCK
  82. default y
  83. help
  84. This option allows you to choose whether you want to have support
  85. for so called swap devices or swap files in your kernel that are
  86. used to provide more virtual memory than the actual RAM present
  87. in your computer. If unsure say Y.
  88. config SYSVIPC
  89. bool "System V IPC"
  90. ---help---
  91. Inter Process Communication is a suite of library functions and
  92. system calls which let processes (running programs) synchronize and
  93. exchange information. It is generally considered to be a good thing,
  94. and some programs won't run unless you say Y here. In particular, if
  95. you want to run the DOS emulator dosemu under Linux (read the
  96. DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
  97. you'll need to say Y here.
  98. You can find documentation about IPC with "info ipc" and also in
  99. section 6.4 of the Linux Programmer's Guide, available from
  100. <http://www.tldp.org/guides.html>.
  101. config IPC_NS
  102. bool "IPC Namespaces"
  103. depends on SYSVIPC
  104. default n
  105. help
  106. Support ipc namespaces. This allows containers, i.e. virtual
  107. environments, to use ipc namespaces to provide different ipc
  108. objects for different servers. If unsure, say N.
  109. config POSIX_MQUEUE
  110. bool "POSIX Message Queues"
  111. depends on NET && EXPERIMENTAL
  112. ---help---
  113. POSIX variant of message queues is a part of IPC. In POSIX message
  114. queues every message has a priority which decides about succession
  115. of receiving it by a process. If you want to compile and run
  116. programs written e.g. for Solaris with use of its POSIX message
  117. queues (functions mq_*) say Y here. To use this feature you will
  118. also need mqueue library, available from
  119. <http://www.mat.uni.torun.pl/~wrona/posix_ipc/>
  120. POSIX message queues are visible as a filesystem called 'mqueue'
  121. and can be mounted somewhere if you want to do filesystem
  122. operations on message queues.
  123. If unsure, say Y.
  124. config BSD_PROCESS_ACCT
  125. bool "BSD Process Accounting"
  126. help
  127. If you say Y here, a user level program will be able to instruct the
  128. kernel (via a special system call) to write process accounting
  129. information to a file: whenever a process exits, information about
  130. that process will be appended to the file by the kernel. The
  131. information includes things such as creation time, owning user,
  132. command name, memory usage, controlling terminal etc. (the complete
  133. list is in the struct acct in <file:include/linux/acct.h>). It is
  134. up to the user level program to do useful things with this
  135. information. This is generally a good idea, so say Y.
  136. config BSD_PROCESS_ACCT_V3
  137. bool "BSD Process Accounting version 3 file format"
  138. depends on BSD_PROCESS_ACCT
  139. default n
  140. help
  141. If you say Y here, the process accounting information is written
  142. in a new file format that also logs the process IDs of each
  143. process and it's parent. Note that this file format is incompatible
  144. with previous v0/v1/v2 file formats, so you will need updated tools
  145. for processing it. A preliminary version of these tools is available
  146. at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>.
  147. config TASKSTATS
  148. bool "Export task/process statistics through netlink (EXPERIMENTAL)"
  149. depends on NET
  150. default n
  151. help
  152. Export selected statistics for tasks/processes through the
  153. generic netlink interface. Unlike BSD process accounting, the
  154. statistics are available during the lifetime of tasks/processes as
  155. responses to commands. Like BSD accounting, they are sent to user
  156. space on task exit.
  157. Say N if unsure.
  158. config TASK_DELAY_ACCT
  159. bool "Enable per-task delay accounting (EXPERIMENTAL)"
  160. depends on TASKSTATS
  161. help
  162. Collect information on time spent by a task waiting for system
  163. resources like cpu, synchronous block I/O completion and swapping
  164. in pages. Such statistics can help in setting a task's priorities
  165. relative to other tasks for cpu, io, rss limits etc.
  166. Say N if unsure.
  167. config TASK_XACCT
  168. bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
  169. depends on TASKSTATS
  170. help
  171. Collect extended task accounting data and send the data
  172. to userland for processing over the taskstats interface.
  173. Say N if unsure.
  174. config TASK_IO_ACCOUNTING
  175. bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
  176. depends on TASK_XACCT
  177. help
  178. Collect information on the number of bytes of storage I/O which this
  179. task has caused.
  180. Say N if unsure.
  181. config UTS_NS
  182. bool "UTS Namespaces"
  183. default n
  184. help
  185. Support uts namespaces. This allows containers, i.e.
  186. vservers, to use uts namespaces to provide different
  187. uts info for different servers. If unsure, say N.
  188. config AUDIT
  189. bool "Auditing support"
  190. depends on NET
  191. help
  192. Enable auditing infrastructure that can be used with another
  193. kernel subsystem, such as SELinux (which requires this for
  194. logging of avc messages output). Does not do system-call
  195. auditing without CONFIG_AUDITSYSCALL.
  196. config AUDITSYSCALL
  197. bool "Enable system-call auditing support"
  198. depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64)
  199. default y if SECURITY_SELINUX
  200. help
  201. Enable low-overhead system-call auditing infrastructure that
  202. can be used independently or with another kernel subsystem,
  203. such as SELinux. To use audit's filesystem watch feature, please
  204. ensure that INOTIFY is configured.
  205. config IKCONFIG
  206. tristate "Kernel .config support"
  207. ---help---
  208. This option enables the complete Linux kernel ".config" file
  209. contents to be saved in the kernel. It provides documentation
  210. of which kernel options are used in a running kernel or in an
  211. on-disk kernel. This information can be extracted from the kernel
  212. image file with the script scripts/extract-ikconfig and used as
  213. input to rebuild the current kernel or to build another kernel.
  214. It can also be extracted from a running kernel by reading
  215. /proc/config.gz if enabled (below).
  216. config IKCONFIG_PROC
  217. bool "Enable access to .config through /proc/config.gz"
  218. depends on IKCONFIG && PROC_FS
  219. ---help---
  220. This option enables access to the kernel configuration file
  221. through /proc/config.gz.
  222. config CPUSETS
  223. bool "Cpuset support"
  224. depends on SMP
  225. help
  226. This option will let you create and manage CPUSETs which
  227. allow dynamically partitioning a system into sets of CPUs and
  228. Memory Nodes and assigning tasks to run only within those sets.
  229. This is primarily useful on large SMP or NUMA systems.
  230. Say N if unsure.
  231. config SYSFS_DEPRECATED
  232. bool "Create deprecated sysfs files"
  233. default y
  234. help
  235. This option creates deprecated symlinks such as the
  236. "device"-link, the <subsystem>:<name>-link, and the
  237. "bus"-link. It may also add deprecated key in the
  238. uevent environment.
  239. None of these features or values should be used today, as
  240. they export driver core implementation details to userspace
  241. or export properties which can't be kept stable across kernel
  242. releases.
  243. If enabled, this option will also move any device structures
  244. that belong to a class, back into the /sys/class heirachy, in
  245. order to support older versions of udev.
  246. If you are using a distro that was released in 2006 or later,
  247. it should be safe to say N here.
  248. config RELAY
  249. bool "Kernel->user space relay support (formerly relayfs)"
  250. help
  251. This option enables support for relay interface support in
  252. certain file systems (such as debugfs).
  253. It is designed to provide an efficient mechanism for tools and
  254. facilities to relay large amounts of data from kernel space to
  255. user space.
  256. If unsure, say N.
  257. if BLK_DEV_INITRD
  258. source "usr/Kconfig"
  259. endif
  260. config CC_OPTIMIZE_FOR_SIZE
  261. bool "Optimize for size (Look out for broken compilers!)"
  262. default y
  263. depends on ARM || H8300 || EXPERIMENTAL
  264. help
  265. Enabling this option will pass "-Os" instead of "-O2" to gcc
  266. resulting in a smaller kernel.
  267. WARNING: some versions of gcc may generate incorrect code with this
  268. option. If problems are observed, a gcc upgrade may be needed.
  269. If unsure, say N.
  270. config SYSCTL
  271. bool
  272. menuconfig EMBEDDED
  273. bool "Configure standard kernel features (for small systems)"
  274. help
  275. This option allows certain base kernel options and settings
  276. to be disabled or tweaked. This is for specialized
  277. environments which can tolerate a "non-standard" kernel.
  278. Only use this if you really know what you are doing.
  279. config UID16
  280. bool "Enable 16-bit UID system calls" if EMBEDDED
  281. depends on ARM || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION)
  282. default y
  283. help
  284. This enables the legacy 16-bit UID syscall wrappers.
  285. config SYSCTL_SYSCALL
  286. bool "Sysctl syscall support" if EMBEDDED
  287. default y
  288. select SYSCTL
  289. ---help---
  290. sys_sysctl uses binary paths that have been found challenging
  291. to properly maintain and use. The interface in /proc/sys
  292. using paths with ascii names is now the primary path to this
  293. information.
  294. Almost nothing using the binary sysctl interface so if you are
  295. trying to save some space it is probably safe to disable this,
  296. making your kernel marginally smaller.
  297. If unsure say Y here.
  298. config KALLSYMS
  299. bool "Load all symbols for debugging/ksymoops" if EMBEDDED
  300. default y
  301. help
  302. Say Y here to let the kernel print out symbolic crash information and
  303. symbolic stack backtraces. This increases the size of the kernel
  304. somewhat, as all symbols have to be loaded into the kernel image.
  305. config KALLSYMS_ALL
  306. bool "Include all symbols in kallsyms"
  307. depends on DEBUG_KERNEL && KALLSYMS
  308. help
  309. Normally kallsyms only contains the symbols of functions, for nicer
  310. OOPS messages. Some debuggers can use kallsyms for other
  311. symbols too: say Y here to include all symbols, if you need them
  312. and you don't care about adding 300k to the size of your kernel.
  313. Say N.
  314. config KALLSYMS_EXTRA_PASS
  315. bool "Do an extra kallsyms pass"
  316. depends on KALLSYMS
  317. help
  318. If kallsyms is not working correctly, the build will fail with
  319. inconsistent kallsyms data. If that occurs, log a bug report and
  320. turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
  321. Always say N here unless you find a bug in kallsyms, which must be
  322. reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
  323. you wait for kallsyms to be fixed.
  324. config HOTPLUG
  325. bool "Support for hot-pluggable devices" if EMBEDDED
  326. default y
  327. help
  328. This option is provided for the case where no hotplug or uevent
  329. capabilities is wanted by the kernel. You should only consider
  330. disabling this option for embedded systems that do not use modules, a
  331. dynamic /dev tree, or dynamic device discovery. Just say Y.
  332. config PRINTK
  333. default y
  334. bool "Enable support for printk" if EMBEDDED
  335. help
  336. This option enables normal printk support. Removing it
  337. eliminates most of the message strings from the kernel image
  338. and makes the kernel more or less silent. As this makes it
  339. very difficult to diagnose system problems, saying N here is
  340. strongly discouraged.
  341. config BUG
  342. bool "BUG() support" if EMBEDDED
  343. default y
  344. help
  345. Disabling this option eliminates support for BUG and WARN, reducing
  346. the size of your kernel image and potentially quietly ignoring
  347. numerous fatal conditions. You should only consider disabling this
  348. option for embedded systems with no facilities for reporting errors.
  349. Just say Y.
  350. config ELF_CORE
  351. default y
  352. bool "Enable ELF core dumps" if EMBEDDED
  353. help
  354. Enable support for generating core dumps. Disabling saves about 4k.
  355. config BASE_FULL
  356. default y
  357. bool "Enable full-sized data structures for core" if EMBEDDED
  358. help
  359. Disabling this option reduces the size of miscellaneous core
  360. kernel data structures. This saves memory on small machines,
  361. but may reduce performance.
  362. config FUTEX
  363. bool "Enable futex support" if EMBEDDED
  364. default y
  365. select RT_MUTEXES
  366. help
  367. Disabling this option will cause the kernel to be built without
  368. support for "fast userspace mutexes". The resulting kernel may not
  369. run glibc-based applications correctly.
  370. config EPOLL
  371. bool "Enable eventpoll support" if EMBEDDED
  372. default y
  373. help
  374. Disabling this option will cause the kernel to be built without
  375. support for epoll family of system calls.
  376. config SHMEM
  377. bool "Use full shmem filesystem" if EMBEDDED
  378. default y
  379. depends on MMU
  380. help
  381. The shmem is an internal filesystem used to manage shared memory.
  382. It is backed by swap and manages resource limits. It is also exported
  383. to userspace as tmpfs if TMPFS is enabled. Disabling this
  384. option replaces shmem and tmpfs with the much simpler ramfs code,
  385. which may be appropriate on small systems without swap.
  386. config SLAB
  387. default y
  388. bool "Use full SLAB allocator" if (EMBEDDED && !SMP && !SPARSEMEM)
  389. help
  390. Disabling this replaces the advanced SLAB allocator and
  391. kmalloc support with the drastically simpler SLOB allocator.
  392. SLOB is more space efficient but does not scale well and is
  393. more susceptible to fragmentation.
  394. config VM_EVENT_COUNTERS
  395. default y
  396. bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
  397. help
  398. VM event counters are needed for event counts to be shown.
  399. This option allows the disabling of the VM event counters
  400. on EMBEDDED systems. /proc/vmstat will only show page counts
  401. if VM event counters are disabled.
  402. endmenu # General setup
  403. config RT_MUTEXES
  404. boolean
  405. select PLIST
  406. config TINY_SHMEM
  407. default !SHMEM
  408. bool
  409. config BASE_SMALL
  410. int
  411. default 0 if BASE_FULL
  412. default 1 if !BASE_FULL
  413. config SLOB
  414. default !SLAB
  415. bool
  416. menu "Loadable module support"
  417. config MODULES
  418. bool "Enable loadable module support"
  419. help
  420. Kernel modules are small pieces of compiled code which can
  421. be inserted in the running kernel, rather than being
  422. permanently built into the kernel. You use the "modprobe"
  423. tool to add (and sometimes remove) them. If you say Y here,
  424. many parts of the kernel can be built as modules (by
  425. answering M instead of Y where indicated): this is most
  426. useful for infrequently used options which are not required
  427. for booting. For more information, see the man pages for
  428. modprobe, lsmod, modinfo, insmod and rmmod.
  429. If you say Y here, you will need to run "make
  430. modules_install" to put the modules under /lib/modules/
  431. where modprobe can find them (you may need to be root to do
  432. this).
  433. If unsure, say Y.
  434. config MODULE_UNLOAD
  435. bool "Module unloading"
  436. depends on MODULES
  437. help
  438. Without this option you will not be able to unload any
  439. modules (note that some modules may not be unloadable
  440. anyway), which makes your kernel slightly smaller and
  441. simpler. If unsure, say Y.
  442. config MODULE_FORCE_UNLOAD
  443. bool "Forced module unloading"
  444. depends on MODULE_UNLOAD && EXPERIMENTAL
  445. help
  446. This option allows you to force a module to unload, even if the
  447. kernel believes it is unsafe: the kernel will remove the module
  448. without waiting for anyone to stop using it (using the -f option to
  449. rmmod). This is mainly for kernel developers and desperate users.
  450. If unsure, say N.
  451. config MODVERSIONS
  452. bool "Module versioning support"
  453. depends on MODULES
  454. help
  455. Usually, you have to use modules compiled with your kernel.
  456. Saying Y here makes it sometimes possible to use modules
  457. compiled for different kernels, by adding enough information
  458. to the modules to (hopefully) spot any changes which would
  459. make them incompatible with the kernel you are running. If
  460. unsure, say N.
  461. config MODULE_SRCVERSION_ALL
  462. bool "Source checksum for all modules"
  463. depends on MODULES
  464. help
  465. Modules which contain a MODULE_VERSION get an extra "srcversion"
  466. field inserted into their modinfo section, which contains a
  467. sum of the source files which made it. This helps maintainers
  468. see exactly which source was used to build a module (since
  469. others sometimes change the module source without updating
  470. the version). With this option, such a "srcversion" field
  471. will be created for all modules. If unsure, say N.
  472. config KMOD
  473. bool "Automatic kernel module loading"
  474. depends on MODULES
  475. help
  476. Normally when you have selected some parts of the kernel to
  477. be created as kernel modules, you must load them (using the
  478. "modprobe" command) before you can use them. If you say Y
  479. here, some parts of the kernel will be able to load modules
  480. automatically: when a part of the kernel needs a module, it
  481. runs modprobe with the appropriate arguments, thereby
  482. loading the module if it is available. If unsure, say Y.
  483. config STOP_MACHINE
  484. bool
  485. default y
  486. depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
  487. help
  488. Need stop_machine() primitive.
  489. endmenu
  490. menu "Block layer"
  491. source "block/Kconfig"
  492. endmenu