Kconfig 18 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502
  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 !UML
  50. default 128 if UML
  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 TASK_DELAY_ACCT
  139. bool "Enable per-task delay accounting (EXPERIMENTAL)"
  140. help
  141. Collect information on time spent by a task waiting for system
  142. resources like cpu, synchronous block I/O completion and swapping
  143. in pages. Such statistics can help in setting a task's priorities
  144. relative to other tasks for cpu, io, rss limits etc.
  145. Say N if unsure.
  146. config SYSCTL
  147. bool "Sysctl support" if EMBEDDED
  148. default y
  149. ---help---
  150. The sysctl interface provides a means of dynamically changing
  151. certain kernel parameters and variables on the fly without requiring
  152. a recompile of the kernel or reboot of the system. The primary
  153. interface consists of a system call, but if you say Y to "/proc
  154. file system support", a tree of modifiable sysctl entries will be
  155. generated beneath the /proc/sys directory. They are explained in the
  156. files in <file:Documentation/sysctl/>. Note that enabling this
  157. option will enlarge the kernel by at least 8 KB.
  158. As it is generally a good thing, you should say Y here unless
  159. building a kernel for install/rescue disks or your system is very
  160. limited in memory.
  161. config AUDIT
  162. bool "Auditing support"
  163. depends on NET
  164. help
  165. Enable auditing infrastructure that can be used with another
  166. kernel subsystem, such as SELinux (which requires this for
  167. logging of avc messages output). Does not do system-call
  168. auditing without CONFIG_AUDITSYSCALL.
  169. config AUDITSYSCALL
  170. bool "Enable system-call auditing support"
  171. depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64)
  172. default y if SECURITY_SELINUX
  173. help
  174. Enable low-overhead system-call auditing infrastructure that
  175. can be used independently or with another kernel subsystem,
  176. such as SELinux. To use audit's filesystem watch feature, please
  177. ensure that INOTIFY is configured.
  178. config IKCONFIG
  179. bool "Kernel .config support"
  180. ---help---
  181. This option enables the complete Linux kernel ".config" file
  182. contents to be saved in the kernel. It provides documentation
  183. of which kernel options are used in a running kernel or in an
  184. on-disk kernel. This information can be extracted from the kernel
  185. image file with the script scripts/extract-ikconfig and used as
  186. input to rebuild the current kernel or to build another kernel.
  187. It can also be extracted from a running kernel by reading
  188. /proc/config.gz if enabled (below).
  189. config IKCONFIG_PROC
  190. bool "Enable access to .config through /proc/config.gz"
  191. depends on IKCONFIG && PROC_FS
  192. ---help---
  193. This option enables access to the kernel configuration file
  194. through /proc/config.gz.
  195. config CPUSETS
  196. bool "Cpuset support"
  197. depends on SMP
  198. help
  199. This option will let you create and manage CPUSETs which
  200. allow dynamically partitioning a system into sets of CPUs and
  201. Memory Nodes and assigning tasks to run only within those sets.
  202. This is primarily useful on large SMP or NUMA systems.
  203. Say N if unsure.
  204. config RELAY
  205. bool "Kernel->user space relay support (formerly relayfs)"
  206. help
  207. This option enables support for relay interface support in
  208. certain file systems (such as debugfs).
  209. It is designed to provide an efficient mechanism for tools and
  210. facilities to relay large amounts of data from kernel space to
  211. user space.
  212. If unsure, say N.
  213. source "usr/Kconfig"
  214. config UID16
  215. bool "Enable 16-bit UID system calls" if EMBEDDED
  216. depends on ARM || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION)
  217. default y
  218. help
  219. This enables the legacy 16-bit UID syscall wrappers.
  220. config CC_OPTIMIZE_FOR_SIZE
  221. bool "Optimize for size (Look out for broken compilers!)"
  222. default y
  223. depends on ARM || H8300 || EXPERIMENTAL
  224. help
  225. Enabling this option will pass "-Os" instead of "-O2" to gcc
  226. resulting in a smaller kernel.
  227. WARNING: some versions of gcc may generate incorrect code with this
  228. option. If problems are observed, a gcc upgrade may be needed.
  229. If unsure, say N.
  230. menuconfig EMBEDDED
  231. bool "Configure standard kernel features (for small systems)"
  232. help
  233. This option allows certain base kernel options and settings
  234. to be disabled or tweaked. This is for specialized
  235. environments which can tolerate a "non-standard" kernel.
  236. Only use this if you really know what you are doing.
  237. config KALLSYMS
  238. bool "Load all symbols for debugging/kksymoops" if EMBEDDED
  239. default y
  240. help
  241. Say Y here to let the kernel print out symbolic crash information and
  242. symbolic stack backtraces. This increases the size of the kernel
  243. somewhat, as all symbols have to be loaded into the kernel image.
  244. config KALLSYMS_ALL
  245. bool "Include all symbols in kallsyms"
  246. depends on DEBUG_KERNEL && KALLSYMS
  247. help
  248. Normally kallsyms only contains the symbols of functions, for nicer
  249. OOPS messages. Some debuggers can use kallsyms for other
  250. symbols too: say Y here to include all symbols, if you need them
  251. and you don't care about adding 300k to the size of your kernel.
  252. Say N.
  253. config KALLSYMS_EXTRA_PASS
  254. bool "Do an extra kallsyms pass"
  255. depends on KALLSYMS
  256. help
  257. If kallsyms is not working correctly, the build will fail with
  258. inconsistent kallsyms data. If that occurs, log a bug report and
  259. turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
  260. Always say N here unless you find a bug in kallsyms, which must be
  261. reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
  262. you wait for kallsyms to be fixed.
  263. config HOTPLUG
  264. bool "Support for hot-pluggable devices" if EMBEDDED
  265. default y
  266. help
  267. This option is provided for the case where no hotplug or uevent
  268. capabilities is wanted by the kernel. You should only consider
  269. disabling this option for embedded systems that do not use modules, a
  270. dynamic /dev tree, or dynamic device discovery. Just say Y.
  271. config PRINTK
  272. default y
  273. bool "Enable support for printk" if EMBEDDED
  274. help
  275. This option enables normal printk support. Removing it
  276. eliminates most of the message strings from the kernel image
  277. and makes the kernel more or less silent. As this makes it
  278. very difficult to diagnose system problems, saying N here is
  279. strongly discouraged.
  280. config BUG
  281. bool "BUG() support" if EMBEDDED
  282. default y
  283. help
  284. Disabling this option eliminates support for BUG and WARN, reducing
  285. the size of your kernel image and potentially quietly ignoring
  286. numerous fatal conditions. You should only consider disabling this
  287. option for embedded systems with no facilities for reporting errors.
  288. Just say Y.
  289. config ELF_CORE
  290. default y
  291. bool "Enable ELF core dumps" if EMBEDDED
  292. help
  293. Enable support for generating core dumps. Disabling saves about 4k.
  294. config BASE_FULL
  295. default y
  296. bool "Enable full-sized data structures for core" if EMBEDDED
  297. help
  298. Disabling this option reduces the size of miscellaneous core
  299. kernel data structures. This saves memory on small machines,
  300. but may reduce performance.
  301. config RT_MUTEXES
  302. boolean
  303. select PLIST
  304. config FUTEX
  305. bool "Enable futex support" if EMBEDDED
  306. default y
  307. select RT_MUTEXES
  308. help
  309. Disabling this option will cause the kernel to be built without
  310. support for "fast userspace mutexes". The resulting kernel may not
  311. run glibc-based applications correctly.
  312. config EPOLL
  313. bool "Enable eventpoll support" if EMBEDDED
  314. default y
  315. help
  316. Disabling this option will cause the kernel to be built without
  317. support for epoll family of system calls.
  318. config SHMEM
  319. bool "Use full shmem filesystem" if EMBEDDED
  320. default y
  321. depends on MMU
  322. help
  323. The shmem is an internal filesystem used to manage shared memory.
  324. It is backed by swap and manages resource limits. It is also exported
  325. to userspace as tmpfs if TMPFS is enabled. Disabling this
  326. option replaces shmem and tmpfs with the much simpler ramfs code,
  327. which may be appropriate on small systems without swap.
  328. config SLAB
  329. default y
  330. bool "Use full SLAB allocator" if EMBEDDED
  331. help
  332. Disabling this replaces the advanced SLAB allocator and
  333. kmalloc support with the drastically simpler SLOB allocator.
  334. SLOB is more space efficient but does not scale well and is
  335. more susceptible to fragmentation.
  336. config VM_EVENT_COUNTERS
  337. default y
  338. bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
  339. help
  340. VM event counters are only needed to for event counts to be
  341. shown. They have no function for the kernel itself. This
  342. option allows the disabling of the VM event counters.
  343. /proc/vmstat will only show page counts.
  344. endmenu # General setup
  345. config TINY_SHMEM
  346. default !SHMEM
  347. bool
  348. config BASE_SMALL
  349. int
  350. default 0 if BASE_FULL
  351. default 1 if !BASE_FULL
  352. config SLOB
  353. default !SLAB
  354. bool
  355. menu "Loadable module support"
  356. config MODULES
  357. bool "Enable loadable module support"
  358. help
  359. Kernel modules are small pieces of compiled code which can
  360. be inserted in the running kernel, rather than being
  361. permanently built into the kernel. You use the "modprobe"
  362. tool to add (and sometimes remove) them. If you say Y here,
  363. many parts of the kernel can be built as modules (by
  364. answering M instead of Y where indicated): this is most
  365. useful for infrequently used options which are not required
  366. for booting. For more information, see the man pages for
  367. modprobe, lsmod, modinfo, insmod and rmmod.
  368. If you say Y here, you will need to run "make
  369. modules_install" to put the modules under /lib/modules/
  370. where modprobe can find them (you may need to be root to do
  371. this).
  372. If unsure, say Y.
  373. config MODULE_UNLOAD
  374. bool "Module unloading"
  375. depends on MODULES
  376. help
  377. Without this option you will not be able to unload any
  378. modules (note that some modules may not be unloadable
  379. anyway), which makes your kernel slightly smaller and
  380. simpler. If unsure, say Y.
  381. config MODULE_FORCE_UNLOAD
  382. bool "Forced module unloading"
  383. depends on MODULE_UNLOAD && EXPERIMENTAL
  384. help
  385. This option allows you to force a module to unload, even if the
  386. kernel believes it is unsafe: the kernel will remove the module
  387. without waiting for anyone to stop using it (using the -f option to
  388. rmmod). This is mainly for kernel developers and desperate users.
  389. If unsure, say N.
  390. config MODVERSIONS
  391. bool "Module versioning support"
  392. depends on MODULES
  393. help
  394. Usually, you have to use modules compiled with your kernel.
  395. Saying Y here makes it sometimes possible to use modules
  396. compiled for different kernels, by adding enough information
  397. to the modules to (hopefully) spot any changes which would
  398. make them incompatible with the kernel you are running. If
  399. unsure, say N.
  400. config MODULE_SRCVERSION_ALL
  401. bool "Source checksum for all modules"
  402. depends on MODULES
  403. help
  404. Modules which contain a MODULE_VERSION get an extra "srcversion"
  405. field inserted into their modinfo section, which contains a
  406. sum of the source files which made it. This helps maintainers
  407. see exactly which source was used to build a module (since
  408. others sometimes change the module source without updating
  409. the version). With this option, such a "srcversion" field
  410. will be created for all modules. If unsure, say N.
  411. config KMOD
  412. bool "Automatic kernel module loading"
  413. depends on MODULES
  414. help
  415. Normally when you have selected some parts of the kernel to
  416. be created as kernel modules, you must load them (using the
  417. "modprobe" command) before you can use them. If you say Y
  418. here, some parts of the kernel will be able to load modules
  419. automatically: when a part of the kernel needs a module, it
  420. runs modprobe with the appropriate arguments, thereby
  421. loading the module if it is available. If unsure, say Y.
  422. config STOP_MACHINE
  423. bool
  424. default y
  425. depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
  426. help
  427. Need stop_machine() primitive.
  428. endmenu
  429. menu "Block layer"
  430. source "block/Kconfig"
  431. endmenu