Kconfig 21 KB

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  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 drivers that have been replaced by something else, and/or are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. # Qisda, Howard Hsu, 2010/01/04, config for RescueOS {
  58. config RESCUEOS_BUILD
  59. bool "Build for RescueOS kernel"
  60. default n
  61. help
  62. Config to distinguish the build is for RescueOS from the normal kernel
  63. # } Qisda, Howard Hsu, 2010/01/04, config for RescueOS
  64. config LOCALVERSION
  65. string "Local version - append to kernel release"
  66. help
  67. Append an extra string to the end of your kernel version.
  68. This will show up when you type uname, for example.
  69. The string you set here will be appended after the contents of
  70. any files with a filename matching localversion* in your
  71. object and source tree, in that order. Your total string can
  72. be a maximum of 64 characters.
  73. config LOCALVERSION_AUTO
  74. bool "Automatically append version information to the version string"
  75. default y
  76. help
  77. This will try to automatically determine if the current tree is a
  78. release tree by looking for git tags that
  79. belong to the current top of tree revision.
  80. A string of the format -gxxxxxxxx will be added to the localversion
  81. if a git based tree is found. The string generated by this will be
  82. appended after any matching localversion* files, and after the value
  83. set in CONFIG_LOCALVERSION
  84. Note: This requires Perl, and a git repository, but not necessarily
  85. the git or cogito tools to be installed.
  86. config SWAP
  87. bool "Support for paging of anonymous memory (swap)"
  88. depends on MMU && BLOCK
  89. default y
  90. help
  91. This option allows you to choose whether you want to have support
  92. for so called swap devices or swap files in your kernel that are
  93. used to provide more virtual memory than the actual RAM present
  94. in your computer. If unsure say Y.
  95. config SYSVIPC
  96. bool "System V IPC"
  97. ---help---
  98. Inter Process Communication is a suite of library functions and
  99. system calls which let processes (running programs) synchronize and
  100. exchange information. It is generally considered to be a good thing,
  101. and some programs won't run unless you say Y here. In particular, if
  102. you want to run the DOS emulator dosemu under Linux (read the
  103. DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
  104. you'll need to say Y here.
  105. You can find documentation about IPC with "info ipc" and also in
  106. section 6.4 of the Linux Programmer's Guide, available from
  107. <http://www.tldp.org/guides.html>.
  108. config IPC_NS
  109. bool "IPC Namespaces"
  110. depends on SYSVIPC
  111. default n
  112. help
  113. Support ipc namespaces. This allows containers, i.e. virtual
  114. environments, to use ipc namespaces to provide different ipc
  115. objects for different servers. If unsure, say N.
  116. config SYSVIPC_SYSCTL
  117. bool
  118. depends on SYSVIPC
  119. depends on SYSCTL
  120. default y
  121. config POSIX_MQUEUE
  122. bool "POSIX Message Queues"
  123. depends on NET && EXPERIMENTAL
  124. ---help---
  125. POSIX variant of message queues is a part of IPC. In POSIX message
  126. queues every message has a priority which decides about succession
  127. of receiving it by a process. If you want to compile and run
  128. programs written e.g. for Solaris with use of its POSIX message
  129. queues (functions mq_*) say Y here. To use this feature you will
  130. also need mqueue library, available from
  131. <http://www.mat.uni.torun.pl/~wrona/posix_ipc/>
  132. POSIX message queues are visible as a filesystem called 'mqueue'
  133. and can be mounted somewhere if you want to do filesystem
  134. operations on message queues.
  135. If unsure, say Y.
  136. config BSD_PROCESS_ACCT
  137. bool "BSD Process Accounting"
  138. help
  139. If you say Y here, a user level program will be able to instruct the
  140. kernel (via a special system call) to write process accounting
  141. information to a file: whenever a process exits, information about
  142. that process will be appended to the file by the kernel. The
  143. information includes things such as creation time, owning user,
  144. command name, memory usage, controlling terminal etc. (the complete
  145. list is in the struct acct in <file:include/linux/acct.h>). It is
  146. up to the user level program to do useful things with this
  147. information. This is generally a good idea, so say Y.
  148. config BSD_PROCESS_ACCT_V3
  149. bool "BSD Process Accounting version 3 file format"
  150. depends on BSD_PROCESS_ACCT
  151. default n
  152. help
  153. If you say Y here, the process accounting information is written
  154. in a new file format that also logs the process IDs of each
  155. process and it's parent. Note that this file format is incompatible
  156. with previous v0/v1/v2 file formats, so you will need updated tools
  157. for processing it. A preliminary version of these tools is available
  158. at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>.
  159. config TASKSTATS
  160. bool "Export task/process statistics through netlink (EXPERIMENTAL)"
  161. depends on NET
  162. default n
  163. help
  164. Export selected statistics for tasks/processes through the
  165. generic netlink interface. Unlike BSD process accounting, the
  166. statistics are available during the lifetime of tasks/processes as
  167. responses to commands. Like BSD accounting, they are sent to user
  168. space on task exit.
  169. Say N if unsure.
  170. config TASK_DELAY_ACCT
  171. bool "Enable per-task delay accounting (EXPERIMENTAL)"
  172. depends on TASKSTATS
  173. help
  174. Collect information on time spent by a task waiting for system
  175. resources like cpu, synchronous block I/O completion and swapping
  176. in pages. Such statistics can help in setting a task's priorities
  177. relative to other tasks for cpu, io, rss limits etc.
  178. Say N if unsure.
  179. config TASK_XACCT
  180. bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
  181. depends on TASKSTATS
  182. help
  183. Collect extended task accounting data and send the data
  184. to userland for processing over the taskstats interface.
  185. Say N if unsure.
  186. config TASK_IO_ACCOUNTING
  187. bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
  188. depends on TASK_XACCT
  189. help
  190. Collect information on the number of bytes of storage I/O which this
  191. task has caused.
  192. Say N if unsure.
  193. config UTS_NS
  194. bool "UTS Namespaces"
  195. default n
  196. help
  197. Support uts namespaces. This allows containers, i.e.
  198. vservers, to use uts namespaces to provide different
  199. uts info for different servers. If unsure, say N.
  200. config AUDIT
  201. bool "Auditing support"
  202. depends on NET
  203. help
  204. Enable auditing infrastructure that can be used with another
  205. kernel subsystem, such as SELinux (which requires this for
  206. logging of avc messages output). Does not do system-call
  207. auditing without CONFIG_AUDITSYSCALL.
  208. config AUDITSYSCALL
  209. bool "Enable system-call auditing support"
  210. depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64)
  211. default y if SECURITY_SELINUX
  212. help
  213. Enable low-overhead system-call auditing infrastructure that
  214. can be used independently or with another kernel subsystem,
  215. such as SELinux. To use audit's filesystem watch feature, please
  216. ensure that INOTIFY is configured.
  217. config IKCONFIG
  218. tristate "Kernel .config support"
  219. ---help---
  220. This option enables the complete Linux kernel ".config" file
  221. contents to be saved in the kernel. It provides documentation
  222. of which kernel options are used in a running kernel or in an
  223. on-disk kernel. This information can be extracted from the kernel
  224. image file with the script scripts/extract-ikconfig and used as
  225. input to rebuild the current kernel or to build another kernel.
  226. It can also be extracted from a running kernel by reading
  227. /proc/config.gz if enabled (below).
  228. config IKCONFIG_PROC
  229. bool "Enable access to .config through /proc/config.gz"
  230. depends on IKCONFIG && PROC_FS
  231. ---help---
  232. This option enables access to the kernel configuration file
  233. through /proc/config.gz.
  234. config CPUSETS
  235. bool "Cpuset support"
  236. depends on SMP
  237. help
  238. This option will let you create and manage CPUSETs which
  239. allow dynamically partitioning a system into sets of CPUs and
  240. Memory Nodes and assigning tasks to run only within those sets.
  241. This is primarily useful on large SMP or NUMA systems.
  242. Say N if unsure.
  243. config SYSFS_DEPRECATED
  244. bool "Create deprecated sysfs files"
  245. default y
  246. help
  247. This option creates deprecated symlinks such as the
  248. "device"-link, the <subsystem>:<name>-link, and the
  249. "bus"-link. It may also add deprecated key in the
  250. uevent environment.
  251. None of these features or values should be used today, as
  252. they export driver core implementation details to userspace
  253. or export properties which can't be kept stable across kernel
  254. releases.
  255. If enabled, this option will also move any device structures
  256. that belong to a class, back into the /sys/class heirachy, in
  257. order to support older versions of udev.
  258. If you are using a distro that was released in 2006 or later,
  259. it should be safe to say N here.
  260. config RELAY
  261. bool "Kernel->user space relay support (formerly relayfs)"
  262. help
  263. This option enables support for relay interface support in
  264. certain file systems (such as debugfs).
  265. It is designed to provide an efficient mechanism for tools and
  266. facilities to relay large amounts of data from kernel space to
  267. user space.
  268. If unsure, say N.
  269. config BLK_DEV_INITRD
  270. bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
  271. depends on BROKEN || !FRV
  272. help
  273. The initial RAM filesystem is a ramfs which is loaded by the
  274. boot loader (loadlin or lilo) and that is mounted as root
  275. before the normal boot procedure. It is typically used to
  276. load modules needed to mount the "real" root file system,
  277. etc. See <file:Documentation/initrd.txt> for details.
  278. If RAM disk support (BLK_DEV_RAM) is also included, this
  279. also enables initial RAM disk (initrd) support and adds
  280. 15 Kbytes (more on some other architectures) to the kernel size.
  281. If unsure say Y.
  282. if BLK_DEV_INITRD
  283. source "usr/Kconfig"
  284. endif
  285. config CC_OPTIMIZE_FOR_SIZE
  286. bool "Optimize for size (Look out for broken compilers!)"
  287. default y
  288. depends on ARM || H8300 || EXPERIMENTAL
  289. help
  290. Enabling this option will pass "-Os" instead of "-O2" to gcc
  291. resulting in a smaller kernel.
  292. WARNING: some versions of gcc may generate incorrect code with this
  293. option. If problems are observed, a gcc upgrade may be needed.
  294. If unsure, say N.
  295. config SYSCTL
  296. bool
  297. menuconfig EMBEDDED
  298. bool "Configure standard kernel features (for small systems)"
  299. help
  300. This option allows certain base kernel options and settings
  301. to be disabled or tweaked. This is for specialized
  302. environments which can tolerate a "non-standard" kernel.
  303. Only use this if you really know what you are doing.
  304. config UID16
  305. bool "Enable 16-bit UID system calls" if EMBEDDED
  306. depends on ARM || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION)
  307. default y
  308. help
  309. This enables the legacy 16-bit UID syscall wrappers.
  310. config SYSCTL_SYSCALL
  311. bool "Sysctl syscall support" if EMBEDDED
  312. default y
  313. select SYSCTL
  314. ---help---
  315. sys_sysctl uses binary paths that have been found challenging
  316. to properly maintain and use. The interface in /proc/sys
  317. using paths with ascii names is now the primary path to this
  318. information.
  319. Almost nothing using the binary sysctl interface so if you are
  320. trying to save some space it is probably safe to disable this,
  321. making your kernel marginally smaller.
  322. If unsure say Y here.
  323. config KALLSYMS
  324. bool "Load all symbols for debugging/ksymoops" if EMBEDDED
  325. default y
  326. help
  327. Say Y here to let the kernel print out symbolic crash information and
  328. symbolic stack backtraces. This increases the size of the kernel
  329. somewhat, as all symbols have to be loaded into the kernel image.
  330. config KALLSYMS_ALL
  331. bool "Include all symbols in kallsyms"
  332. depends on DEBUG_KERNEL && KALLSYMS
  333. help
  334. Normally kallsyms only contains the symbols of functions, for nicer
  335. OOPS messages. Some debuggers can use kallsyms for other
  336. symbols too: say Y here to include all symbols, if you need them
  337. and you don't care about adding 300k to the size of your kernel.
  338. Say N.
  339. config KALLSYMS_EXTRA_PASS
  340. bool "Do an extra kallsyms pass"
  341. depends on KALLSYMS
  342. help
  343. If kallsyms is not working correctly, the build will fail with
  344. inconsistent kallsyms data. If that occurs, log a bug report and
  345. turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
  346. Always say N here unless you find a bug in kallsyms, which must be
  347. reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
  348. you wait for kallsyms to be fixed.
  349. config HOTPLUG
  350. bool "Support for hot-pluggable devices" if EMBEDDED
  351. default y
  352. help
  353. This option is provided for the case where no hotplug or uevent
  354. capabilities is wanted by the kernel. You should only consider
  355. disabling this option for embedded systems that do not use modules, a
  356. dynamic /dev tree, or dynamic device discovery. Just say Y.
  357. config PRINTK
  358. default y
  359. bool "Enable support for printk" if EMBEDDED
  360. help
  361. This option enables normal printk support. Removing it
  362. eliminates most of the message strings from the kernel image
  363. and makes the kernel more or less silent. As this makes it
  364. very difficult to diagnose system problems, saying N here is
  365. strongly discouraged.
  366. config BUG
  367. bool "BUG() support" if EMBEDDED
  368. default y
  369. help
  370. Disabling this option eliminates support for BUG and WARN, reducing
  371. the size of your kernel image and potentially quietly ignoring
  372. numerous fatal conditions. You should only consider disabling this
  373. option for embedded systems with no facilities for reporting errors.
  374. Just say Y.
  375. config ELF_CORE
  376. default y
  377. bool "Enable ELF core dumps" if EMBEDDED
  378. help
  379. Enable support for generating core dumps. Disabling saves about 4k.
  380. config BASE_FULL
  381. default y
  382. bool "Enable full-sized data structures for core" if EMBEDDED
  383. help
  384. Disabling this option reduces the size of miscellaneous core
  385. kernel data structures. This saves memory on small machines,
  386. but may reduce performance.
  387. config FUTEX
  388. bool "Enable futex support" if EMBEDDED
  389. default y
  390. select RT_MUTEXES
  391. help
  392. Disabling this option will cause the kernel to be built without
  393. support for "fast userspace mutexes". The resulting kernel may not
  394. run glibc-based applications correctly.
  395. config EPOLL
  396. bool "Enable eventpoll support" if EMBEDDED
  397. default y
  398. help
  399. Disabling this option will cause the kernel to be built without
  400. support for epoll family of system calls.
  401. config SHMEM
  402. bool "Use full shmem filesystem" if EMBEDDED
  403. default y
  404. depends on MMU
  405. help
  406. The shmem is an internal filesystem used to manage shared memory.
  407. It is backed by swap and manages resource limits. It is also exported
  408. to userspace as tmpfs if TMPFS is enabled. Disabling this
  409. option replaces shmem and tmpfs with the much simpler ramfs code,
  410. which may be appropriate on small systems without swap.
  411. config SLAB
  412. default y
  413. bool "Use full SLAB allocator" if (EMBEDDED && !SMP && !SPARSEMEM)
  414. help
  415. Disabling this replaces the advanced SLAB allocator and
  416. kmalloc support with the drastically simpler SLOB allocator.
  417. SLOB is more space efficient but does not scale well and is
  418. more susceptible to fragmentation.
  419. config VM_EVENT_COUNTERS
  420. default y
  421. bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
  422. help
  423. VM event counters are needed for event counts to be shown.
  424. This option allows the disabling of the VM event counters
  425. on EMBEDDED systems. /proc/vmstat will only show page counts
  426. if VM event counters are disabled.
  427. endmenu # General setup
  428. config RT_MUTEXES
  429. boolean
  430. select PLIST
  431. config TINY_SHMEM
  432. default !SHMEM
  433. bool
  434. config BASE_SMALL
  435. int
  436. default 0 if BASE_FULL
  437. default 1 if !BASE_FULL
  438. config SLOB
  439. default !SLAB
  440. bool
  441. menu "Loadable module support"
  442. config MODULES
  443. bool "Enable loadable module support"
  444. help
  445. Kernel modules are small pieces of compiled code which can
  446. be inserted in the running kernel, rather than being
  447. permanently built into the kernel. You use the "modprobe"
  448. tool to add (and sometimes remove) them. If you say Y here,
  449. many parts of the kernel can be built as modules (by
  450. answering M instead of Y where indicated): this is most
  451. useful for infrequently used options which are not required
  452. for booting. For more information, see the man pages for
  453. modprobe, lsmod, modinfo, insmod and rmmod.
  454. If you say Y here, you will need to run "make
  455. modules_install" to put the modules under /lib/modules/
  456. where modprobe can find them (you may need to be root to do
  457. this).
  458. If unsure, say Y.
  459. config MODULE_UNLOAD
  460. bool "Module unloading"
  461. depends on MODULES
  462. help
  463. Without this option you will not be able to unload any
  464. modules (note that some modules may not be unloadable
  465. anyway), which makes your kernel slightly smaller and
  466. simpler. If unsure, say Y.
  467. config MODULE_FORCE_UNLOAD
  468. bool "Forced module unloading"
  469. depends on MODULE_UNLOAD && EXPERIMENTAL
  470. help
  471. This option allows you to force a module to unload, even if the
  472. kernel believes it is unsafe: the kernel will remove the module
  473. without waiting for anyone to stop using it (using the -f option to
  474. rmmod). This is mainly for kernel developers and desperate users.
  475. If unsure, say N.
  476. config MODVERSIONS
  477. bool "Module versioning support"
  478. depends on MODULES
  479. help
  480. Usually, you have to use modules compiled with your kernel.
  481. Saying Y here makes it sometimes possible to use modules
  482. compiled for different kernels, by adding enough information
  483. to the modules to (hopefully) spot any changes which would
  484. make them incompatible with the kernel you are running. If
  485. unsure, say N.
  486. config MODULE_SRCVERSION_ALL
  487. bool "Source checksum for all modules"
  488. depends on MODULES
  489. help
  490. Modules which contain a MODULE_VERSION get an extra "srcversion"
  491. field inserted into their modinfo section, which contains a
  492. sum of the source files which made it. This helps maintainers
  493. see exactly which source was used to build a module (since
  494. others sometimes change the module source without updating
  495. the version). With this option, such a "srcversion" field
  496. will be created for all modules. If unsure, say N.
  497. config KMOD
  498. bool "Automatic kernel module loading"
  499. depends on MODULES
  500. help
  501. Normally when you have selected some parts of the kernel to
  502. be created as kernel modules, you must load them (using the
  503. "modprobe" command) before you can use them. If you say Y
  504. here, some parts of the kernel will be able to load modules
  505. automatically: when a part of the kernel needs a module, it
  506. runs modprobe with the appropriate arguments, thereby
  507. loading the module if it is available. If unsure, say Y.
  508. config STOP_MACHINE
  509. bool
  510. default y
  511. depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
  512. help
  513. Need stop_machine() primitive.
  514. endmenu
  515. menu "Block layer"
  516. source "block/Kconfig"
  517. endmenu