Kconfig 18 KB

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 drivers that have been replaced by something else, and/or are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