| blob | b170aa1d43bd127c75b7380237e18bbb2f1c3f2e |
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"
10 menu "Code maturity level options"
12 config EXPERIMENTAL
13 bool "Prompt for development and/or incomplete code/drivers"
14 ---help---
15 Some of the various things that Linux supports (such as network
16 drivers, file systems, network protocols, etc.) can be in a state
17 of development where the functionality, stability, or the level of
18 testing is not yet high enough for general use. This is usually
19 known as the "alpha-test" phase among developers. If a feature is
20 currently in alpha-test, then the developers usually discourage
21 uninformed widespread use of this feature by the general public to
22 avoid "Why doesn't this work?" type mail messages. However, active
23 testing and use of these systems is welcomed. Just be aware that it
24 may not meet the normal level of reliability or it may fail to work
25 in some special cases. Detailed bug reports from people familiar
26 with the kernel internals are usually welcomed by the developers
27 (before submitting bug reports, please read the documents
28 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
29 <file:Documentation/BUG-HUNTING>, and
30 <file:Documentation/oops-tracing.txt> in the kernel source).
32 This option will also make obsoleted drivers available. These are
33 drivers that have been replaced by something else, and/or are
34 scheduled to be removed in a future kernel release.
36 Unless you intend to help test and develop a feature or driver that
37 falls into this category, or you have a situation that requires
38 using these features, you should probably say N here, which will
39 cause the configurator to present you with fewer choices. If
40 you say Y here, you will be offered the choice of using features or
41 drivers that are currently considered to be in the alpha-test phase.
43 config BROKEN
44 bool
46 config BROKEN_ON_SMP
47 bool
48 depends on BROKEN || !SMP
49 default y
51 config LOCK_KERNEL
52 bool
53 depends on SMP || PREEMPT
54 default y
56 config INIT_ENV_ARG_LIMIT
57 int
58 default 32 if !UML
59 default 128 if UML
60 help
61 Maximum of each of the number of arguments and environment
62 variables passed to init from the kernel command line.
64 endmenu
66 menu "General setup"
68 config LOCALVERSION
69 string "Local version - append to kernel release"
70 help
71 Append an extra string to the end of your kernel version.
72 This will show up when you type uname, for example.
73 The string you set here will be appended after the contents of
74 any files with a filename matching localversion* in your
75 object and source tree, in that order. Your total string can
76 be a maximum of 64 characters.
78 config LOCALVERSION_AUTO
79 bool "Automatically append version information to the version string"
80 default y
81 help
82 This will try to automatically determine if the current tree is a
83 release tree by looking for git tags that
84 belong to the current top of tree revision.
86 A string of the format -gxxxxxxxx will be added to the localversion
87 if a git based tree is found. The string generated by this will be
88 appended after any matching localversion* files, and after the value
89 set in CONFIG_LOCALVERSION
91 Note: This requires Perl, and a git repository, but not necessarily
92 the git or cogito tools to be installed.
94 config SWAP
95 bool "Support for paging of anonymous memory (swap)"
96 depends on MMU && BLOCK
97 default y
98 help
99 This option allows you to choose whether you want to have support
100 for so called swap devices or swap files in your kernel that are
101 used to provide more virtual memory than the actual RAM present
102 in your computer. If unsure say Y.
104 config SYSVIPC
105 bool "System V IPC"
106 ---help---
107 Inter Process Communication is a suite of library functions and
108 system calls which let processes (running programs) synchronize and
109 exchange information. It is generally considered to be a good thing,
110 and some programs won't run unless you say Y here. In particular, if
111 you want to run the DOS emulator dosemu under Linux (read the
112 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
113 you'll need to say Y here.
115 You can find documentation about IPC with "info ipc" and also in
116 section 6.4 of the Linux Programmer's Guide, available from
117 <http://www.tldp.org/guides.html>.
119 config IPC_NS
120 bool "IPC Namespaces"
121 depends on SYSVIPC
122 default n
123 help
124 Support ipc namespaces. This allows containers, i.e. virtual
125 environments, to use ipc namespaces to provide different ipc
126 objects for different servers. If unsure, say N.
128 config SYSVIPC_SYSCTL
129 bool
130 depends on SYSVIPC
131 depends on SYSCTL
132 default y
134 config POSIX_MQUEUE
135 bool "POSIX Message Queues"
136 depends on NET && EXPERIMENTAL
137 ---help---
138 POSIX variant of message queues is a part of IPC. In POSIX message
139 queues every message has a priority which decides about succession
140 of receiving it by a process. If you want to compile and run
141 programs written e.g. for Solaris with use of its POSIX message
142 queues (functions mq_*) say Y here. To use this feature you will
143 also need mqueue library, available from
144 <http://www.mat.uni.torun.pl/~wrona/posix_ipc/>
146 POSIX message queues are visible as a filesystem called 'mqueue'
147 and can be mounted somewhere if you want to do filesystem
148 operations on message queues.
150 If unsure, say Y.
152 config BSD_PROCESS_ACCT
153 bool "BSD Process Accounting"
154 help
155 If you say Y here, a user level program will be able to instruct the
156 kernel (via a special system call) to write process accounting
157 information to a file: whenever a process exits, information about
158 that process will be appended to the file by the kernel. The
159 information includes things such as creation time, owning user,
160 command name, memory usage, controlling terminal etc. (the complete
161 list is in the struct acct in <file:include/linux/acct.h>). It is
162 up to the user level program to do useful things with this
163 information. This is generally a good idea, so say Y.
165 config BSD_PROCESS_ACCT_V3
166 bool "BSD Process Accounting version 3 file format"
167 depends on BSD_PROCESS_ACCT
168 default n
169 help
170 If you say Y here, the process accounting information is written
171 in a new file format that also logs the process IDs of each
172 process and it's parent. Note that this file format is incompatible
173 with previous v0/v1/v2 file formats, so you will need updated tools
174 for processing it. A preliminary version of these tools is available
175 at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>.
177 config TASKSTATS
178 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
179 depends on NET
180 default n
181 help
182 Export selected statistics for tasks/processes through the
183 generic netlink interface. Unlike BSD process accounting, the
184 statistics are available during the lifetime of tasks/processes as
185 responses to commands. Like BSD accounting, they are sent to user
186 space on task exit.
188 Say N if unsure.
190 config TASK_DELAY_ACCT
191 bool "Enable per-task delay accounting (EXPERIMENTAL)"
192 depends on TASKSTATS
193 help
194 Collect information on time spent by a task waiting for system
195 resources like cpu, synchronous block I/O completion and swapping
196 in pages. Such statistics can help in setting a task's priorities
197 relative to other tasks for cpu, io, rss limits etc.
199 Say N if unsure.
201 config TASK_XACCT
202 bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
203 depends on TASKSTATS
204 help
205 Collect extended task accounting data and send the data
206 to userland for processing over the taskstats interface.
208 Say N if unsure.
210 config TASK_IO_ACCOUNTING
211 bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
212 depends on TASK_XACCT
213 help
214 Collect information on the number of bytes of storage I/O which this
215 task has caused.
217 Say N if unsure.
219 config UTS_NS
220 bool "UTS Namespaces"
221 default n
222 help
223 Support uts namespaces. This allows containers, i.e.
224 vservers, to use uts namespaces to provide different
225 uts info for different servers. If unsure, say N.
227 config AUDIT
228 bool "Auditing support"
229 depends on NET
230 help
231 Enable auditing infrastructure that can be used with another
232 kernel subsystem, such as SELinux (which requires this for
233 logging of avc messages output). Does not do system-call
234 auditing without CONFIG_AUDITSYSCALL.
236 config AUDITSYSCALL
237 bool "Enable system-call auditing support"
238 depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64)
239 default y if SECURITY_SELINUX
240 help
241 Enable low-overhead system-call auditing infrastructure that
242 can be used independently or with another kernel subsystem,
243 such as SELinux. To use audit's filesystem watch feature, please
244 ensure that INOTIFY is configured.
246 config IKCONFIG
247 tristate "Kernel .config support"
248 ---help---
249 This option enables the complete Linux kernel ".config" file
250 contents to be saved in the kernel. It provides documentation
251 of which kernel options are used in a running kernel or in an
252 on-disk kernel. This information can be extracted from the kernel
253 image file with the script scripts/extract-ikconfig and used as
254 input to rebuild the current kernel or to build another kernel.
255 It can also be extracted from a running kernel by reading
256 /proc/config.gz if enabled (below).
258 config IKCONFIG_PROC
259 bool "Enable access to .config through /proc/config.gz"
260 depends on IKCONFIG && PROC_FS
261 ---help---
262 This option enables access to the kernel configuration file
263 through /proc/config.gz.
265 config CPUSETS
266 bool "Cpuset support"
267 depends on SMP
268 help
269 This option will let you create and manage CPUSETs which
270 allow dynamically partitioning a system into sets of CPUs and
271 Memory Nodes and assigning tasks to run only within those sets.
272 This is primarily useful on large SMP or NUMA systems.
274 Say N if unsure.
276 config SYSFS_DEPRECATED
277 bool "Create deprecated sysfs files"
278 default y
279 help
280 This option creates deprecated symlinks such as the
281 "device"-link, the <subsystem>:<name>-link, and the
282 "bus"-link. It may also add deprecated key in the
283 uevent environment.
284 None of these features or values should be used today, as
285 they export driver core implementation details to userspace
286 or export properties which can't be kept stable across kernel
287 releases.
289 If enabled, this option will also move any device structures
290 that belong to a class, back into the /sys/class heirachy, in
291 order to support older versions of udev.
293 If you are using a distro that was released in 2006 or later,
294 it should be safe to say N here.
296 config RELAY
297 bool "Kernel->user space relay support (formerly relayfs)"
298 help
299 This option enables support for relay interface support in
300 certain file systems (such as debugfs).
301 It is designed to provide an efficient mechanism for tools and
302 facilities to relay large amounts of data from kernel space to
303 user space.
305 If unsure, say N.
307 config BLK_DEV_INITRD
308 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
309 depends on BROKEN || !FRV
310 help
311 The initial RAM filesystem is a ramfs which is loaded by the
312 boot loader (loadlin or lilo) and that is mounted as root
313 before the normal boot procedure. It is typically used to
314 load modules needed to mount the "real" root file system,
315 etc. See <file:Documentation/initrd.txt> for details.
317 If RAM disk support (BLK_DEV_RAM) is also included, this
318 also enables initial RAM disk (initrd) support and adds
319 15 Kbytes (more on some other architectures) to the kernel size.
321 If unsure say Y.
323 if BLK_DEV_INITRD
325 source "usr/Kconfig"
327 endif
329 config CC_OPTIMIZE_FOR_SIZE
330 bool "Optimize for size (Look out for broken compilers!)"
331 default y
332 depends on ARM || H8300 || EXPERIMENTAL
333 help
334 Enabling this option will pass "-Os" instead of "-O2" to gcc
335 resulting in a smaller kernel.
337 WARNING: some versions of gcc may generate incorrect code with this
338 option. If problems are observed, a gcc upgrade may be needed.
340 If unsure, say N.
342 config SYSCTL
343 bool
345 menuconfig EMBEDDED
346 bool "Configure standard kernel features (for small systems)"
347 help
348 This option allows certain base kernel options and settings
349 to be disabled or tweaked. This is for specialized
350 environments which can tolerate a "non-standard" kernel.
351 Only use this if you really know what you are doing.
353 config UID16
354 bool "Enable 16-bit UID system calls" if EMBEDDED
355 depends on ARM || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION)
356 default y
357 help
358 This enables the legacy 16-bit UID syscall wrappers.
360 config SYSCTL_SYSCALL
361 bool "Sysctl syscall support" if EMBEDDED
362 default y
363 select SYSCTL
364 ---help---
365 sys_sysctl uses binary paths that have been found challenging
366 to properly maintain and use. The interface in /proc/sys
367 using paths with ascii names is now the primary path to this
368 information.
370 Almost nothing using the binary sysctl interface so if you are
371 trying to save some space it is probably safe to disable this,
372 making your kernel marginally smaller.
374 If unsure say Y here.
376 config KALLSYMS
377 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
378 default y
379 help
380 Say Y here to let the kernel print out symbolic crash information and
381 symbolic stack backtraces. This increases the size of the kernel
382 somewhat, as all symbols have to be loaded into the kernel image.
384 config KALLSYMS_ALL
385 bool "Include all symbols in kallsyms"
386 depends on DEBUG_KERNEL && KALLSYMS
387 help
388 Normally kallsyms only contains the symbols of functions, for nicer
389 OOPS messages. Some debuggers can use kallsyms for other
390 symbols too: say Y here to include all symbols, if you need them
391 and you don't care about adding 300k to the size of your kernel.
393 Say N.
395 config KALLSYMS_EXTRA_PASS
396 bool "Do an extra kallsyms pass"
397 depends on KALLSYMS
398 help
399 If kallsyms is not working correctly, the build will fail with
400 inconsistent kallsyms data. If that occurs, log a bug report and
401 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
402 Always say N here unless you find a bug in kallsyms, which must be
403 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
404 you wait for kallsyms to be fixed.
407 config HOTPLUG
408 bool "Support for hot-pluggable devices" if EMBEDDED
409 default y
410 help
411 This option is provided for the case where no hotplug or uevent
412 capabilities is wanted by the kernel. You should only consider
413 disabling this option for embedded systems that do not use modules, a
414 dynamic /dev tree, or dynamic device discovery. Just say Y.
416 config PRINTK
417 default y
418 bool "Enable support for printk" if EMBEDDED
419 help
420 This option enables normal printk support. Removing it
421 eliminates most of the message strings from the kernel image
422 and makes the kernel more or less silent. As this makes it
423 very difficult to diagnose system problems, saying N here is
424 strongly discouraged.
426 config BUG
427 bool "BUG() support" if EMBEDDED
428 default y
429 help
430 Disabling this option eliminates support for BUG and WARN, reducing
431 the size of your kernel image and potentially quietly ignoring
432 numerous fatal conditions. You should only consider disabling this
433 option for embedded systems with no facilities for reporting errors.
434 Just say Y.
436 config ELF_CORE
437 default y
438 bool "Enable ELF core dumps" if EMBEDDED
439 help
440 Enable support for generating core dumps. Disabling saves about 4k.
442 config BASE_FULL
443 default y
444 bool "Enable full-sized data structures for core" if EMBEDDED
445 help
446 Disabling this option reduces the size of miscellaneous core
447 kernel data structures. This saves memory on small machines,
448 but may reduce performance.
450 config FUTEX
451 bool "Enable futex support" if EMBEDDED
452 default y
453 select RT_MUTEXES
454 help
455 Disabling this option will cause the kernel to be built without
456 support for "fast userspace mutexes". The resulting kernel may not
457 run glibc-based applications correctly.
459 config EPOLL
460 bool "Enable eventpoll support" if EMBEDDED
461 default y
462 help
463 Disabling this option will cause the kernel to be built without
464 support for epoll family of system calls.
466 config SHMEM
467 bool "Use full shmem filesystem" if EMBEDDED
468 default y
469 depends on MMU
470 help
471 The shmem is an internal filesystem used to manage shared memory.
472 It is backed by swap and manages resource limits. It is also exported
473 to userspace as tmpfs if TMPFS is enabled. Disabling this
474 option replaces shmem and tmpfs with the much simpler ramfs code,
475 which may be appropriate on small systems without swap.
477 config SLAB
478 default y
479 bool "Use full SLAB allocator" if (EMBEDDED && !SMP && !SPARSEMEM)
480 help
481 Disabling this replaces the advanced SLAB allocator and
482 kmalloc support with the drastically simpler SLOB allocator.
483 SLOB is more space efficient but does not scale well and is
484 more susceptible to fragmentation.
486 config VM_EVENT_COUNTERS
487 default y
488 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
489 help
490 VM event counters are needed for event counts to be shown.
491 This option allows the disabling of the VM event counters
492 on EMBEDDED systems. /proc/vmstat will only show page counts
493 if VM event counters are disabled.
495 endmenu # General setup
497 config RT_MUTEXES
498 boolean
499 select PLIST
501 config TINY_SHMEM
502 default !SHMEM
503 bool
505 config BASE_SMALL
506 int
507 default 0 if BASE_FULL
508 default 1 if !BASE_FULL
510 config SLOB
511 default !SLAB
512 bool
514 menu "Loadable module support"
516 config MODULES
517 bool "Enable loadable module support"
518 help
519 Kernel modules are small pieces of compiled code which can
520 be inserted in the running kernel, rather than being
521 permanently built into the kernel. You use the "modprobe"
522 tool to add (and sometimes remove) them. If you say Y here,
523 many parts of the kernel can be built as modules (by
524 answering M instead of Y where indicated): this is most
525 useful for infrequently used options which are not required
526 for booting. For more information, see the man pages for
527 modprobe, lsmod, modinfo, insmod and rmmod.
529 If you say Y here, you will need to run "make
530 modules_install" to put the modules under /lib/modules/
531 where modprobe can find them (you may need to be root to do
532 this).
534 If unsure, say Y.
536 config MODULE_UNLOAD
537 bool "Module unloading"
538 depends on MODULES
539 help
540 Without this option you will not be able to unload any
541 modules (note that some modules may not be unloadable
542 anyway), which makes your kernel slightly smaller and
543 simpler. If unsure, say Y.
545 config MODULE_FORCE_UNLOAD
546 bool "Forced module unloading"
547 depends on MODULE_UNLOAD && EXPERIMENTAL
548 help
549 This option allows you to force a module to unload, even if the
550 kernel believes it is unsafe: the kernel will remove the module
551 without waiting for anyone to stop using it (using the -f option to
552 rmmod). This is mainly for kernel developers and desperate users.
553 If unsure, say N.
555 config MODVERSIONS
556 bool "Module versioning support"
557 depends on MODULES
558 help
559 Usually, you have to use modules compiled with your kernel.
560 Saying Y here makes it sometimes possible to use modules
561 compiled for different kernels, by adding enough information
562 to the modules to (hopefully) spot any changes which would
563 make them incompatible with the kernel you are running. If
564 unsure, say N.
566 config MODULE_SRCVERSION_ALL
567 bool "Source checksum for all modules"
568 depends on MODULES
569 help
570 Modules which contain a MODULE_VERSION get an extra "srcversion"
571 field inserted into their modinfo section, which contains a
572 sum of the source files which made it. This helps maintainers
573 see exactly which source was used to build a module (since
574 others sometimes change the module source without updating
575 the version). With this option, such a "srcversion" field
576 will be created for all modules. If unsure, say N.
578 config KMOD
579 bool "Automatic kernel module loading"
580 depends on MODULES
581 help
582 Normally when you have selected some parts of the kernel to
583 be created as kernel modules, you must load them (using the
584 "modprobe" command) before you can use them. If you say Y
585 here, some parts of the kernel will be able to load modules
586 automatically: when a part of the kernel needs a module, it
587 runs modprobe with the appropriate arguments, thereby
588 loading the module if it is available. If unsure, say Y.
590 config STOP_MACHINE
591 bool
592 default y
593 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
594 help
595 Need stop_machine() primitive.
596 endmenu
598 menu "Block layer"
599 source "block/Kconfig"
600 endmenu