Kconfig 17 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489
  1. config DEFCONFIG_LIST
  2. string
  3. option defconfig_list
  4. default "/lib/modules/$UNAME_RELEASE/.config"
  5. default "/etc/kernel-config"
  6. default "/boot/config-$UNAME_RELEASE"
  7. default "arch/$ARCH/defconfig"
  8. menu "Code maturity level options"
  9. config EXPERIMENTAL
  10. bool "Prompt for development and/or incomplete code/drivers"
  11. ---help---
  12. Some of the various things that Linux supports (such as network
  13. drivers, file systems, network protocols, etc.) can be in a state
  14. of development where the functionality, stability, or the level of
  15. testing is not yet high enough for general use. This is usually
  16. known as the "alpha-test" phase among developers. If a feature is
  17. currently in alpha-test, then the developers usually discourage
  18. uninformed widespread use of this feature by the general public to
  19. avoid "Why doesn't this work?" type mail messages. However, active
  20. testing and use of these systems is welcomed. Just be aware that it
  21. may not meet the normal level of reliability or it may fail to work
  22. in some special cases. Detailed bug reports from people familiar
  23. with the kernel internals are usually welcomed by the developers
  24. (before submitting bug reports, please read the documents
  25. <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
  26. <file:Documentation/BUG-HUNTING>, and
  27. <file:Documentation/oops-tracing.txt> in the kernel source).
  28. This option will also make obsoleted drivers available. These are
  29. drivers that have been replaced by something else, and/or are
  30. scheduled to be removed in a future kernel release.
  31. Unless you intend to help test and develop a feature or driver that
  32. falls into this category, or you have a situation that requires
  33. using these features, you should probably say N here, which will
  34. cause the configurator to present you with fewer choices. If
  35. you say Y here, you will be offered the choice of using features or
  36. drivers that are currently considered to be in the alpha-test phase.
  37. config BROKEN
  38. bool
  39. config BROKEN_ON_SMP
  40. bool
  41. depends on BROKEN || !SMP
  42. default y
  43. config LOCK_KERNEL
  44. bool
  45. depends on SMP || PREEMPT
  46. default y
  47. config INIT_ENV_ARG_LIMIT
  48. int
  49. default 32 if !USERMODE
  50. default 128 if USERMODE
  51. help
  52. Maximum of each of the number of arguments and environment
  53. variables passed to init from the kernel command line.
  54. endmenu
  55. menu "General setup"
  56. config LOCALVERSION
  57. string "Local version - append to kernel release"
  58. help
  59. Append an extra string to the end of your kernel version.
  60. This will show up when you type uname, for example.
  61. The string you set here will be appended after the contents of
  62. any files with a filename matching localversion* in your
  63. object and source tree, in that order. Your total string can
  64. be a maximum of 64 characters.
  65. config LOCALVERSION_AUTO
  66. bool "Automatically append version information to the version string"
  67. default y
  68. help
  69. This will try to automatically determine if the current tree is a
  70. release tree by looking for git tags that
  71. belong to the current top of tree revision.
  72. A string of the format -gxxxxxxxx will be added to the localversion
  73. if a git based tree is found. The string generated by this will be
  74. appended after any matching localversion* files, and after the value
  75. set in CONFIG_LOCALVERSION
  76. Note: This requires Perl, and a git repository, but not necessarily
  77. the git or cogito tools to be installed.
  78. config SWAP
  79. bool "Support for paging of anonymous memory (swap)"
  80. depends on MMU
  81. default y
  82. help
  83. This option allows you to choose whether you want to have support
  84. for so called swap devices or swap files in your kernel that are
  85. used to provide more virtual memory than the actual RAM present
  86. in your computer. If unsure say Y.
  87. config SYSVIPC
  88. bool "System V IPC"
  89. ---help---
  90. Inter Process Communication is a suite of library functions and
  91. system calls which let processes (running programs) synchronize and
  92. exchange information. It is generally considered to be a good thing,
  93. and some programs won't run unless you say Y here. In particular, if
  94. you want to run the DOS emulator dosemu under Linux (read the
  95. DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
  96. you'll need to say Y here.
  97. You can find documentation about IPC with "info ipc" and also in
  98. section 6.4 of the Linux Programmer's Guide, available from
  99. <http://www.tldp.org/guides.html>.
  100. config POSIX_MQUEUE
  101. bool "POSIX Message Queues"
  102. depends on NET && EXPERIMENTAL
  103. ---help---
  104. POSIX variant of message queues is a part of IPC. In POSIX message
  105. queues every message has a priority which decides about succession
  106. of receiving it by a process. If you want to compile and run
  107. programs written e.g. for Solaris with use of its POSIX message
  108. queues (functions mq_*) say Y here. To use this feature you will
  109. also need mqueue library, available from
  110. <http://www.mat.uni.torun.pl/~wrona/posix_ipc/>
  111. POSIX message queues are visible as a filesystem called 'mqueue'
  112. and can be mounted somewhere if you want to do filesystem
  113. operations on message queues.
  114. If unsure, say Y.
  115. config BSD_PROCESS_ACCT
  116. bool "BSD Process Accounting"
  117. help
  118. If you say Y here, a user level program will be able to instruct the
  119. kernel (via a special system call) to write process accounting
  120. information to a file: whenever a process exits, information about
  121. that process will be appended to the file by the kernel. The
  122. information includes things such as creation time, owning user,
  123. command name, memory usage, controlling terminal etc. (the complete
  124. list is in the struct acct in <file:include/linux/acct.h>). It is
  125. up to the user level program to do useful things with this
  126. information. This is generally a good idea, so say Y.
  127. config BSD_PROCESS_ACCT_V3
  128. bool "BSD Process Accounting version 3 file format"
  129. depends on BSD_PROCESS_ACCT
  130. default n
  131. help
  132. If you say Y here, the process accounting information is written
  133. in a new file format that also logs the process IDs of each
  134. process and it's parent. Note that this file format is incompatible
  135. with previous v0/v1/v2 file formats, so you will need updated tools
  136. for processing it. A preliminary version of these tools is available
  137. at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>.
  138. config SYSCTL
  139. bool "Sysctl support"
  140. ---help---
  141. The sysctl interface provides a means of dynamically changing
  142. certain kernel parameters and variables on the fly without requiring
  143. a recompile of the kernel or reboot of the system. The primary
  144. interface consists of a system call, but if you say Y to "/proc
  145. file system support", a tree of modifiable sysctl entries will be
  146. generated beneath the /proc/sys directory. They are explained in the
  147. files in <file:Documentation/sysctl/>. Note that enabling this
  148. option will enlarge the kernel by at least 8 KB.
  149. As it is generally a good thing, you should say Y here unless
  150. building a kernel for install/rescue disks or your system is very
  151. limited in memory.
  152. config AUDIT
  153. bool "Auditing support"
  154. depends on NET
  155. help
  156. Enable auditing infrastructure that can be used with another
  157. kernel subsystem, such as SELinux (which requires this for
  158. logging of avc messages output). Does not do system-call
  159. auditing without CONFIG_AUDITSYSCALL.
  160. config AUDITSYSCALL
  161. bool "Enable system-call auditing support"
  162. depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64)
  163. default y if SECURITY_SELINUX
  164. help
  165. Enable low-overhead system-call auditing infrastructure that
  166. can be used independently or with another kernel subsystem,
  167. such as SELinux.
  168. config IKCONFIG
  169. bool "Kernel .config support"
  170. ---help---
  171. This option enables the complete Linux kernel ".config" file
  172. contents to be saved in the kernel. It provides documentation
  173. of which kernel options are used in a running kernel or in an
  174. on-disk kernel. This information can be extracted from the kernel
  175. image file with the script scripts/extract-ikconfig and used as
  176. input to rebuild the current kernel or to build another kernel.
  177. It can also be extracted from a running kernel by reading
  178. /proc/config.gz if enabled (below).
  179. config IKCONFIG_PROC
  180. bool "Enable access to .config through /proc/config.gz"
  181. depends on IKCONFIG && PROC_FS
  182. ---help---
  183. This option enables access to the kernel configuration file
  184. through /proc/config.gz.
  185. config CPUSETS
  186. bool "Cpuset support"
  187. depends on SMP
  188. help
  189. This option will let you create and manage CPUSETs which
  190. allow dynamically partitioning a system into sets of CPUs and
  191. Memory Nodes and assigning tasks to run only within those sets.
  192. This is primarily useful on large SMP or NUMA systems.
  193. Say N if unsure.
  194. config RELAY
  195. bool "Kernel->user space relay support (formerly relayfs)"
  196. help
  197. This option enables support for relay interface support in
  198. certain file systems (such as debugfs).
  199. It is designed to provide an efficient mechanism for tools and
  200. facilities to relay large amounts of data from kernel space to
  201. user space.
  202. If unsure, say N.
  203. source "usr/Kconfig"
  204. config UID16
  205. bool "Enable 16-bit UID system calls" if EMBEDDED
  206. depends on ARM || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION)
  207. default y
  208. help
  209. This enables the legacy 16-bit UID syscall wrappers.
  210. config VM86
  211. depends X86
  212. default y
  213. bool "Enable VM86 support" if EMBEDDED
  214. help
  215. This option is required by programs like DOSEMU to run 16-bit legacy
  216. code on X86 processors. It also may be needed by software like
  217. XFree86 to initialize some video cards via BIOS. Disabling this
  218. option saves about 6k.
  219. config CC_OPTIMIZE_FOR_SIZE
  220. bool "Optimize for size (Look out for broken compilers!)"
  221. default y
  222. depends on ARM || H8300 || EXPERIMENTAL
  223. help
  224. Enabling this option will pass "-Os" instead of "-O2" to gcc
  225. resulting in a smaller kernel.
  226. WARNING: some versions of gcc may generate incorrect code with this
  227. option. If problems are observed, a gcc upgrade may be needed.
  228. If unsure, say N.
  229. menuconfig EMBEDDED
  230. bool "Configure standard kernel features (for small systems)"
  231. help
  232. This option allows certain base kernel options and settings
  233. to be disabled or tweaked. This is for specialized
  234. environments which can tolerate a "non-standard" kernel.
  235. Only use this if you really know what you are doing.
  236. config KALLSYMS
  237. bool "Load all symbols for debugging/kksymoops" if EMBEDDED
  238. default y
  239. help
  240. Say Y here to let the kernel print out symbolic crash information and
  241. symbolic stack backtraces. This increases the size of the kernel
  242. somewhat, as all symbols have to be loaded into the kernel image.
  243. config KALLSYMS_ALL
  244. bool "Include all symbols in kallsyms"
  245. depends on DEBUG_KERNEL && KALLSYMS
  246. help
  247. Normally kallsyms only contains the symbols of functions, for nicer
  248. OOPS messages. Some debuggers can use kallsyms for other
  249. symbols too: say Y here to include all symbols, if you need them
  250. and you don't care about adding 300k to the size of your kernel.
  251. Say N.
  252. config KALLSYMS_EXTRA_PASS
  253. bool "Do an extra kallsyms pass"
  254. depends on KALLSYMS
  255. help
  256. If kallsyms is not working correctly, the build will fail with
  257. inconsistent kallsyms data. If that occurs, log a bug report and
  258. turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
  259. Always say N here unless you find a bug in kallsyms, which must be
  260. reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
  261. you wait for kallsyms to be fixed.
  262. config HOTPLUG
  263. bool "Support for hot-pluggable devices" if EMBEDDED
  264. default y
  265. help
  266. This option is provided for the case where no hotplug or uevent
  267. capabilities is wanted by the kernel. You should only consider
  268. disabling this option for embedded systems that do not use modules, a
  269. dynamic /dev tree, or dynamic device discovery. Just say Y.
  270. config PRINTK
  271. default y
  272. bool "Enable support for printk" if EMBEDDED
  273. help
  274. This option enables normal printk support. Removing it
  275. eliminates most of the message strings from the kernel image
  276. and makes the kernel more or less silent. As this makes it
  277. very difficult to diagnose system problems, saying N here is
  278. strongly discouraged.
  279. config BUG
  280. bool "BUG() support" if EMBEDDED
  281. default y
  282. help
  283. Disabling this option eliminates support for BUG and WARN, reducing
  284. the size of your kernel image and potentially quietly ignoring
  285. numerous fatal conditions. You should only consider disabling this
  286. option for embedded systems with no facilities for reporting errors.
  287. Just say Y.
  288. config ELF_CORE
  289. default y
  290. bool "Enable ELF core dumps" if EMBEDDED
  291. help
  292. Enable support for generating core dumps. Disabling saves about 4k.
  293. config BASE_FULL
  294. default y
  295. bool "Enable full-sized data structures for core" if EMBEDDED
  296. help
  297. Disabling this option reduces the size of miscellaneous core
  298. kernel data structures. This saves memory on small machines,
  299. but may reduce performance.
  300. config FUTEX
  301. bool "Enable futex support" if EMBEDDED
  302. default y
  303. help
  304. Disabling this option will cause the kernel to be built without
  305. support for "fast userspace mutexes". The resulting kernel may not
  306. run glibc-based applications correctly.
  307. config EPOLL
  308. bool "Enable eventpoll support" if EMBEDDED
  309. default y
  310. help
  311. Disabling this option will cause the kernel to be built without
  312. support for epoll family of system calls.
  313. config SHMEM
  314. bool "Use full shmem filesystem" if EMBEDDED
  315. default y
  316. depends on MMU
  317. help
  318. The shmem is an internal filesystem used to manage shared memory.
  319. It is backed by swap and manages resource limits. It is also exported
  320. to userspace as tmpfs if TMPFS is enabled. Disabling this
  321. option replaces shmem and tmpfs with the much simpler ramfs code,
  322. which may be appropriate on small systems without swap.
  323. config SLAB
  324. default y
  325. bool "Use full SLAB allocator" if EMBEDDED
  326. help
  327. Disabling this replaces the advanced SLAB allocator and
  328. kmalloc support with the drastically simpler SLOB allocator.
  329. SLOB is more space efficient but does not scale well and is
  330. more susceptible to fragmentation.
  331. endmenu # General setup
  332. config TINY_SHMEM
  333. default !SHMEM
  334. bool
  335. config BASE_SMALL
  336. int
  337. default 0 if BASE_FULL
  338. default 1 if !BASE_FULL
  339. config SLOB
  340. default !SLAB
  341. bool
  342. config OBSOLETE_INTERMODULE
  343. tristate
  344. menu "Loadable module support"
  345. config MODULES
  346. bool "Enable loadable module support"
  347. help
  348. Kernel modules are small pieces of compiled code which can
  349. be inserted in the running kernel, rather than being
  350. permanently built into the kernel. You use the "modprobe"
  351. tool to add (and sometimes remove) them. If you say Y here,
  352. many parts of the kernel can be built as modules (by
  353. answering M instead of Y where indicated): this is most
  354. useful for infrequently used options which are not required
  355. for booting. For more information, see the man pages for
  356. modprobe, lsmod, modinfo, insmod and rmmod.
  357. If you say Y here, you will need to run "make
  358. modules_install" to put the modules under /lib/modules/
  359. where modprobe can find them (you may need to be root to do
  360. this).
  361. If unsure, say Y.
  362. config MODULE_UNLOAD
  363. bool "Module unloading"
  364. depends on MODULES
  365. help
  366. Without this option you will not be able to unload any
  367. modules (note that some modules may not be unloadable
  368. anyway), which makes your kernel slightly smaller and
  369. simpler. If unsure, say Y.
  370. config MODULE_FORCE_UNLOAD
  371. bool "Forced module unloading"
  372. depends on MODULE_UNLOAD && EXPERIMENTAL
  373. help
  374. This option allows you to force a module to unload, even if the
  375. kernel believes it is unsafe: the kernel will remove the module
  376. without waiting for anyone to stop using it (using the -f option to
  377. rmmod). This is mainly for kernel developers and desperate users.
  378. If unsure, say N.
  379. config MODVERSIONS
  380. bool "Module versioning support"
  381. depends on MODULES
  382. help
  383. Usually, you have to use modules compiled with your kernel.
  384. Saying Y here makes it sometimes possible to use modules
  385. compiled for different kernels, by adding enough information
  386. to the modules to (hopefully) spot any changes which would
  387. make them incompatible with the kernel you are running. If
  388. unsure, say N.
  389. config MODULE_SRCVERSION_ALL
  390. bool "Source checksum for all modules"
  391. depends on MODULES
  392. help
  393. Modules which contain a MODULE_VERSION get an extra "srcversion"
  394. field inserted into their modinfo section, which contains a
  395. sum of the source files which made it. This helps maintainers
  396. see exactly which source was used to build a module (since
  397. others sometimes change the module source without updating
  398. the version). With this option, such a "srcversion" field
  399. will be created for all modules. If unsure, say N.
  400. config KMOD
  401. bool "Automatic kernel module loading"
  402. depends on MODULES
  403. help
  404. Normally when you have selected some parts of the kernel to
  405. be created as kernel modules, you must load them (using the
  406. "modprobe" command) before you can use them. If you say Y
  407. here, some parts of the kernel will be able to load modules
  408. automatically: when a part of the kernel needs a module, it
  409. runs modprobe with the appropriate arguments, thereby
  410. loading the module if it is available. If unsure, say Y.
  411. config STOP_MACHINE
  412. bool
  413. default y
  414. depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
  415. help
  416. Need stop_machine() primitive.
  417. endmenu
  418. menu "Block layer"
  419. source "block/Kconfig"
  420. endmenu