Kconfig 17 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490
  1. menu "Code maturity level options"
  2. config EXPERIMENTAL
  3. bool "Prompt for development and/or incomplete code/drivers"
  4. ---help---
  5. Some of the various things that Linux supports (such as network
  6. drivers, file systems, network protocols, etc.) can be in a state
  7. of development where the functionality, stability, or the level of
  8. testing is not yet high enough for general use. This is usually
  9. known as the "alpha-test" phase among developers. If a feature is
  10. currently in alpha-test, then the developers usually discourage
  11. uninformed widespread use of this feature by the general public to
  12. avoid "Why doesn't this work?" type mail messages. However, active
  13. testing and use of these systems is welcomed. Just be aware that it
  14. may not meet the normal level of reliability or it may fail to work
  15. in some special cases. Detailed bug reports from people familiar
  16. with the kernel internals are usually welcomed by the developers
  17. (before submitting bug reports, please read the documents
  18. <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
  19. <file:Documentation/BUG-HUNTING>, and
  20. <file:Documentation/oops-tracing.txt> in the kernel source).
  21. This option will also make obsoleted drivers available. These are
  22. drivers that have been replaced by something else, and/or are
  23. scheduled to be removed in a future kernel release.
  24. Unless you intend to help test and develop a feature or driver that
  25. falls into this category, or you have a situation that requires
  26. using these features, you should probably say N here, which will
  27. cause the configurator to present you with fewer choices. If
  28. you say Y here, you will be offered the choice of using features or
  29. drivers that are currently considered to be in the alpha-test phase.
  30. config CLEAN_COMPILE
  31. bool "Select only drivers expected to compile cleanly" if EXPERIMENTAL
  32. default y
  33. help
  34. Select this option if you don't even want to see the option
  35. to configure known-broken drivers.
  36. If unsure, say Y
  37. config BROKEN
  38. bool
  39. depends on !CLEAN_COMPILE
  40. default y
  41. config BROKEN_ON_SMP
  42. bool
  43. depends on BROKEN || !SMP
  44. default y
  45. config LOCK_KERNEL
  46. bool
  47. depends on SMP || PREEMPT
  48. default y
  49. config INIT_ENV_ARG_LIMIT
  50. int
  51. default 32 if !USERMODE
  52. default 128 if USERMODE
  53. help
  54. Maximum of each of the number of arguments and environment
  55. variables passed to init from the kernel command line.
  56. endmenu
  57. menu "General setup"
  58. config LOCALVERSION
  59. string "Local version - append to kernel release"
  60. help
  61. Append an extra string to the end of your kernel version.
  62. This will show up when you type uname, for example.
  63. The string you set here will be appended after the contents of
  64. any files with a filename matching localversion* in your
  65. object and source tree, in that order. Your total string can
  66. be a maximum of 64 characters.
  67. config LOCALVERSION_AUTO
  68. bool "Automatically append version information to the version string"
  69. default y
  70. help
  71. This will try to automatically determine if the current tree is a
  72. release tree by looking for git tags that
  73. belong to the current top of tree revision.
  74. A string of the format -gxxxxxxxx will be added to the localversion
  75. if a git based tree is found. The string generated by this will be
  76. appended after any matching localversion* files, and after the value
  77. set in CONFIG_LOCALVERSION
  78. Note: This requires Perl, and a git repository, but not necessarily
  79. the git or cogito tools to be installed.
  80. config SWAP
  81. bool "Support for paging of anonymous memory (swap)"
  82. depends on MMU
  83. default y
  84. help
  85. This option allows you to choose whether you want to have support
  86. for socalled swap devices or swap files in your kernel that are
  87. used to provide more virtual memory than the actual RAM present
  88. in your computer. If unsure say Y.
  89. config SYSVIPC
  90. bool "System V IPC"
  91. depends on MMU
  92. ---help---
  93. Inter Process Communication is a suite of library functions and
  94. system calls which let processes (running programs) synchronize and
  95. exchange information. It is generally considered to be a good thing,
  96. and some programs won't run unless you say Y here. In particular, if
  97. you want to run the DOS emulator dosemu under Linux (read the
  98. DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
  99. you'll need to say Y here.
  100. You can find documentation about IPC with "info ipc" and also in
  101. section 6.4 of the Linux Programmer's Guide, available from
  102. <http://www.tldp.org/guides.html>.
  103. config POSIX_MQUEUE
  104. bool "POSIX Message Queues"
  105. depends on NET && EXPERIMENTAL
  106. ---help---
  107. POSIX variant of message queues is a part of IPC. In POSIX message
  108. queues every message has a priority which decides about succession
  109. of receiving it by a process. If you want to compile and run
  110. programs written e.g. for Solaris with use of its POSIX message
  111. queues (functions mq_*) say Y here. To use this feature you will
  112. also need mqueue library, available from
  113. <http://www.mat.uni.torun.pl/~wrona/posix_ipc/>
  114. POSIX message queues are visible as a filesystem called 'mqueue'
  115. and can be mounted somewhere if you want to do filesystem
  116. operations on message queues.
  117. If unsure, say Y.
  118. config BSD_PROCESS_ACCT
  119. bool "BSD Process Accounting"
  120. help
  121. If you say Y here, a user level program will be able to instruct the
  122. kernel (via a special system call) to write process accounting
  123. information to a file: whenever a process exits, information about
  124. that process will be appended to the file by the kernel. The
  125. information includes things such as creation time, owning user,
  126. command name, memory usage, controlling terminal etc. (the complete
  127. list is in the struct acct in <file:include/linux/acct.h>). It is
  128. up to the user level program to do useful things with this
  129. information. This is generally a good idea, so say Y.
  130. config BSD_PROCESS_ACCT_V3
  131. bool "BSD Process Accounting version 3 file format"
  132. depends on BSD_PROCESS_ACCT
  133. default n
  134. help
  135. If you say Y here, the process accounting information is written
  136. in a new file format that also logs the process IDs of each
  137. process and it's parent. Note that this file format is incompatible
  138. with previous v0/v1/v2 file formats, so you will need updated tools
  139. for processing it. A preliminary version of these tools is available
  140. at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>.
  141. config SYSCTL
  142. bool "Sysctl support"
  143. ---help---
  144. The sysctl interface provides a means of dynamically changing
  145. certain kernel parameters and variables on the fly without requiring
  146. a recompile of the kernel or reboot of the system. The primary
  147. interface consists of a system call, but if you say Y to "/proc
  148. file system support", a tree of modifiable sysctl entries will be
  149. generated beneath the /proc/sys directory. They are explained in the
  150. files in <file:Documentation/sysctl/>. Note that enabling this
  151. option will enlarge the kernel by at least 8 KB.
  152. As it is generally a good thing, you should say Y here unless
  153. building a kernel for install/rescue disks or your system is very
  154. limited in memory.
  155. config AUDIT
  156. bool "Auditing support"
  157. depends on NET
  158. default y if SECURITY_SELINUX
  159. help
  160. Enable auditing infrastructure that can be used with another
  161. kernel subsystem, such as SELinux (which requires this for
  162. logging of avc messages output). Does not do system-call
  163. auditing without CONFIG_AUDITSYSCALL.
  164. config AUDITSYSCALL
  165. bool "Enable system-call auditing support"
  166. depends on AUDIT && (X86 || PPC || PPC64 || ARCH_S390 || IA64 || UML || SPARC64)
  167. default y if SECURITY_SELINUX
  168. help
  169. Enable low-overhead system-call auditing infrastructure that
  170. can be used independently or with another kernel subsystem,
  171. such as SELinux.
  172. config IKCONFIG
  173. bool "Kernel .config support"
  174. ---help---
  175. This option enables the complete Linux kernel ".config" file
  176. contents to be saved in the kernel. It provides documentation
  177. of which kernel options are used in a running kernel or in an
  178. on-disk kernel. This information can be extracted from the kernel
  179. image file with the script scripts/extract-ikconfig and used as
  180. input to rebuild the current kernel or to build another kernel.
  181. It can also be extracted from a running kernel by reading
  182. /proc/config.gz if enabled (below).
  183. config IKCONFIG_PROC
  184. bool "Enable access to .config through /proc/config.gz"
  185. depends on IKCONFIG && PROC_FS
  186. ---help---
  187. This option enables access to the kernel configuration file
  188. through /proc/config.gz.
  189. config CPUSETS
  190. bool "Cpuset support"
  191. depends on SMP
  192. help
  193. This option will let you create and manage CPUSETs which
  194. allow dynamically partitioning a system into sets of CPUs and
  195. Memory Nodes and assigning tasks to run only within those sets.
  196. This is primarily useful on large SMP or NUMA systems.
  197. Say N if unsure.
  198. source "usr/Kconfig"
  199. config CC_OPTIMIZE_FOR_SIZE
  200. bool "Optimize for size (Look out for broken compilers!)"
  201. default y
  202. depends on ARM || H8300 || EXPERIMENTAL
  203. help
  204. Enabling this option will pass "-Os" instead of "-O2" to gcc
  205. resulting in a smaller kernel.
  206. WARNING: some versions of gcc may generate incorrect code with this
  207. option. If problems are observed, a gcc upgrade may be needed.
  208. If unsure, say N.
  209. menuconfig EMBEDDED
  210. bool "Configure standard kernel features (for small systems)"
  211. help
  212. This option allows certain base kernel options and settings
  213. to be disabled or tweaked. This is for specialized
  214. environments which can tolerate a "non-standard" kernel.
  215. Only use this if you really know what you are doing.
  216. config KALLSYMS
  217. bool "Load all symbols for debugging/kksymoops" if EMBEDDED
  218. default y
  219. help
  220. Say Y here to let the kernel print out symbolic crash information and
  221. symbolic stack backtraces. This increases the size of the kernel
  222. somewhat, as all symbols have to be loaded into the kernel image.
  223. config KALLSYMS_ALL
  224. bool "Include all symbols in kallsyms"
  225. depends on DEBUG_KERNEL && KALLSYMS
  226. help
  227. Normally kallsyms only contains the symbols of functions, for nicer
  228. OOPS messages. Some debuggers can use kallsyms for other
  229. symbols too: say Y here to include all symbols, if you need them
  230. and you don't care about adding 300k to the size of your kernel.
  231. Say N.
  232. config KALLSYMS_EXTRA_PASS
  233. bool "Do an extra kallsyms pass"
  234. depends on KALLSYMS
  235. help
  236. If kallsyms is not working correctly, the build will fail with
  237. inconsistent kallsyms data. If that occurs, log a bug report and
  238. turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
  239. Always say N here unless you find a bug in kallsyms, which must be
  240. reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
  241. you wait for kallsyms to be fixed.
  242. config HOTPLUG
  243. bool "Support for hot-pluggable devices" if EMBEDDED
  244. default y
  245. help
  246. This option is provided for the case where no hotplug or uevent
  247. capabilities is wanted by the kernel. You should only consider
  248. disabling this option for embedded systems that do not use modules, a
  249. dynamic /dev tree, or dynamic device discovery. Just say Y.
  250. config PRINTK
  251. default y
  252. bool "Enable support for printk" if EMBEDDED
  253. help
  254. This option enables normal printk support. Removing it
  255. eliminates most of the message strings from the kernel image
  256. and makes the kernel more or less silent. As this makes it
  257. very difficult to diagnose system problems, saying N here is
  258. strongly discouraged.
  259. config BUG
  260. bool "BUG() support" if EMBEDDED
  261. default y
  262. help
  263. Disabling this option eliminates support for BUG and WARN, reducing
  264. the size of your kernel image and potentially quietly ignoring
  265. numerous fatal conditions. You should only consider disabling this
  266. option for embedded systems with no facilities for reporting errors.
  267. Just say Y.
  268. config BASE_FULL
  269. default y
  270. bool "Enable full-sized data structures for core" if EMBEDDED
  271. help
  272. Disabling this option reduces the size of miscellaneous core
  273. kernel data structures. This saves memory on small machines,
  274. but may reduce performance.
  275. config FUTEX
  276. bool "Enable futex support" if EMBEDDED
  277. default y
  278. help
  279. Disabling this option will cause the kernel to be built without
  280. support for "fast userspace mutexes". The resulting kernel may not
  281. run glibc-based applications correctly.
  282. config EPOLL
  283. bool "Enable eventpoll support" if EMBEDDED
  284. default y
  285. help
  286. Disabling this option will cause the kernel to be built without
  287. support for epoll family of system calls.
  288. config SHMEM
  289. bool "Use full shmem filesystem" if EMBEDDED
  290. default y
  291. depends on MMU
  292. help
  293. The shmem is an internal filesystem used to manage shared memory.
  294. It is backed by swap and manages resource limits. It is also exported
  295. to userspace as tmpfs if TMPFS is enabled. Disabling this
  296. option replaces shmem and tmpfs with the much simpler ramfs code,
  297. which may be appropriate on small systems without swap.
  298. config CC_ALIGN_FUNCTIONS
  299. int "Function alignment" if EMBEDDED
  300. default 0
  301. help
  302. Align the start of functions to the next power-of-two greater than n,
  303. skipping up to n bytes. For instance, 32 aligns functions
  304. to the next 32-byte boundary, but 24 would align to the next
  305. 32-byte boundary only if this can be done by skipping 23 bytes or less.
  306. Zero means use compiler's default.
  307. config CC_ALIGN_LABELS
  308. int "Label alignment" if EMBEDDED
  309. default 0
  310. help
  311. Align all branch targets to a power-of-two boundary, skipping
  312. up to n bytes like ALIGN_FUNCTIONS. This option can easily
  313. make code slower, because it must insert dummy operations for
  314. when the branch target is reached in the usual flow of the code.
  315. Zero means use compiler's default.
  316. config CC_ALIGN_LOOPS
  317. int "Loop alignment" if EMBEDDED
  318. default 0
  319. help
  320. Align loops to a power-of-two boundary, skipping up to n bytes.
  321. Zero means use compiler's default.
  322. config CC_ALIGN_JUMPS
  323. int "Jump alignment" if EMBEDDED
  324. default 0
  325. help
  326. Align branch targets to a power-of-two boundary, for branch
  327. targets where the targets can only be reached by jumping,
  328. skipping up to n bytes like ALIGN_FUNCTIONS. In this case,
  329. no dummy operations need be executed.
  330. Zero means use compiler's default.
  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. menu "Loadable module support"
  340. config MODULES
  341. bool "Enable loadable module support"
  342. help
  343. Kernel modules are small pieces of compiled code which can
  344. be inserted in the running kernel, rather than being
  345. permanently built into the kernel. You use the "modprobe"
  346. tool to add (and sometimes remove) them. If you say Y here,
  347. many parts of the kernel can be built as modules (by
  348. answering M instead of Y where indicated): this is most
  349. useful for infrequently used options which are not required
  350. for booting. For more information, see the man pages for
  351. modprobe, lsmod, modinfo, insmod and rmmod.
  352. If you say Y here, you will need to run "make
  353. modules_install" to put the modules under /lib/modules/
  354. where modprobe can find them (you may need to be root to do
  355. this).
  356. If unsure, say Y.
  357. config MODULE_UNLOAD
  358. bool "Module unloading"
  359. depends on MODULES
  360. help
  361. Without this option you will not be able to unload any
  362. modules (note that some modules may not be unloadable
  363. anyway), which makes your kernel slightly smaller and
  364. simpler. If unsure, say Y.
  365. config MODULE_FORCE_UNLOAD
  366. bool "Forced module unloading"
  367. depends on MODULE_UNLOAD && EXPERIMENTAL
  368. help
  369. This option allows you to force a module to unload, even if the
  370. kernel believes it is unsafe: the kernel will remove the module
  371. without waiting for anyone to stop using it (using the -f option to
  372. rmmod). This is mainly for kernel developers and desperate users.
  373. If unsure, say N.
  374. config OBSOLETE_MODPARM
  375. bool
  376. default y
  377. depends on MODULES
  378. help
  379. You need this option to use module parameters on modules which
  380. have not been converted to the new module parameter system yet.
  381. If unsure, say Y.
  382. config MODVERSIONS
  383. bool "Module versioning support"
  384. depends on MODULES
  385. help
  386. Usually, you have to use modules compiled with your kernel.
  387. Saying Y here makes it sometimes possible to use modules
  388. compiled for different kernels, by adding enough information
  389. to the modules to (hopefully) spot any changes which would
  390. make them incompatible with the kernel you are running. If
  391. unsure, say N.
  392. config MODULE_SRCVERSION_ALL
  393. bool "Source checksum for all modules"
  394. depends on MODULES
  395. help
  396. Modules which contain a MODULE_VERSION get an extra "srcversion"
  397. field inserted into their modinfo section, which contains a
  398. sum of the source files which made it. This helps maintainers
  399. see exactly which source was used to build a module (since
  400. others sometimes change the module source without updating
  401. the version). With this option, such a "srcversion" field
  402. will be created for all modules. If unsure, say N.
  403. config KMOD
  404. bool "Automatic kernel module loading"
  405. depends on MODULES
  406. help
  407. Normally when you have selected some parts of the kernel to
  408. be created as kernel modules, you must load them (using the
  409. "modprobe" command) before you can use them. If you say Y
  410. here, some parts of the kernel will be able to load modules
  411. automatically: when a part of the kernel needs a module, it
  412. runs modprobe with the appropriate arguments, thereby
  413. loading the module if it is available. If unsure, say Y.
  414. config STOP_MACHINE
  415. bool
  416. default y
  417. depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
  418. help
  419. Need stop_machine() primitive.
  420. endmenu
  421. menu "Block layer"
  422. source "block/Kconfig"
  423. endmenu