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1config 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
9menu "Code maturity level options"
10
11config EXPERIMENTAL
12 bool "Prompt for development and/or incomplete code/drivers"
13 ---help---
14 Some of the various things that Linux supports (such as network
15 drivers, file systems, network protocols, etc.) can be in a state
16 of development where the functionality, stability, or the level of
17 testing is not yet high enough for general use. This is usually
18 known as the "alpha-test" phase among developers. If a feature is
19 currently in alpha-test, then the developers usually discourage
20 uninformed widespread use of this feature by the general public to
21 avoid "Why doesn't this work?" type mail messages. However, active
22 testing and use of these systems is welcomed. Just be aware that it
23 may not meet the normal level of reliability or it may fail to work
24 in some special cases. Detailed bug reports from people familiar
25 with the kernel internals are usually welcomed by the developers
26 (before submitting bug reports, please read the documents
27 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
28 <file:Documentation/BUG-HUNTING>, and
29 <file:Documentation/oops-tracing.txt> in the kernel source).
30
31 This option will also make obsoleted drivers available. These are
32 drivers that have been replaced by something else, and/or are
33 scheduled to be removed in a future kernel release.
34
35 Unless you intend to help test and develop a feature or driver that
36 falls into this category, or you have a situation that requires
37 using these features, you should probably say N here, which will
38 cause the configurator to present you with fewer choices. If
39 you say Y here, you will be offered the choice of using features or
40 drivers that are currently considered to be in the alpha-test phase.
41
42config BROKEN
43 bool
44
45config BROKEN_ON_SMP
46 bool
47 depends on BROKEN || !SMP
48 default y
49
50config LOCK_KERNEL
51 bool
52 depends on SMP || PREEMPT
53 default y
54
55config INIT_ENV_ARG_LIMIT
56 int
57 default 32 if !USERMODE
58 default 128 if USERMODE
59 help
60 Maximum of each of the number of arguments and environment
61 variables passed to init from the kernel command line.
62
63endmenu
64
65menu "General setup"
66
67config LOCALVERSION
68 string "Local version - append to kernel release"
69 help
70 Append an extra string to the end of your kernel version.
71 This will show up when you type uname, for example.
72 The string you set here will be appended after the contents of
73 any files with a filename matching localversion* in your
74 object and source tree, in that order. Your total string can
75 be a maximum of 64 characters.
76
77config LOCALVERSION_AUTO
78 bool "Automatically append version information to the version string"
79 default y
80 help
81 This will try to automatically determine if the current tree is a
82 release tree by looking for git tags that
83 belong to the current top of tree revision.
84
85 A string of the format -gxxxxxxxx will be added to the localversion
86 if a git based tree is found. The string generated by this will be
87 appended after any matching localversion* files, and after the value
88 set in CONFIG_LOCALVERSION
89
90 Note: This requires Perl, and a git repository, but not necessarily
91 the git or cogito tools to be installed.
92
93config SWAP
94 bool "Support for paging of anonymous memory (swap)"
95 depends on MMU
96 default y
97 help
98 This option allows you to choose whether you want to have support
99 for so called swap devices or swap files in your kernel that are
100 used to provide more virtual memory than the actual RAM present
101 in your computer. If unsure say Y.
102
103config SYSVIPC
104 bool "System V IPC"
105 ---help---
106 Inter Process Communication is a suite of library functions and
107 system calls which let processes (running programs) synchronize and
108 exchange information. It is generally considered to be a good thing,
109 and some programs won't run unless you say Y here. In particular, if
110 you want to run the DOS emulator dosemu under Linux (read the
111 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
112 you'll need to say Y here.
113
114 You can find documentation about IPC with "info ipc" and also in
115 section 6.4 of the Linux Programmer's Guide, available from
116 <http://www.tldp.org/guides.html>.
117
118config POSIX_MQUEUE
119 bool "POSIX Message Queues"
120 depends on NET && EXPERIMENTAL
121 ---help---
122 POSIX variant of message queues is a part of IPC. In POSIX message
123 queues every message has a priority which decides about succession
124 of receiving it by a process. If you want to compile and run
125 programs written e.g. for Solaris with use of its POSIX message
126 queues (functions mq_*) say Y here. To use this feature you will
127 also need mqueue library, available from
128 <http://www.mat.uni.torun.pl/~wrona/posix_ipc/>
129
130 POSIX message queues are visible as a filesystem called 'mqueue'
131 and can be mounted somewhere if you want to do filesystem
132 operations on message queues.
133
134 If unsure, say Y.
135
136config 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
149config BSD_PROCESS_ACCT_V3
150 bool "BSD Process Accounting version 3 file format"
151 depends on BSD_PROCESS_ACCT
152 default n
153 help
154 If you say Y here, the process accounting information is written
155 in a new file format that also logs the process IDs of each
156 process and it's parent. Note that this file format is incompatible
157 with previous v0/v1/v2 file formats, so you will need updated tools
158 for processing it. A preliminary version of these tools is available
159 at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>.
160
161config SYSCTL
162 bool "Sysctl support" if EMBEDDED
163 default y
164 ---help---
165 The sysctl interface provides a means of dynamically changing
166 certain kernel parameters and variables on the fly without requiring
167 a recompile of the kernel or reboot of the system. The primary
168 interface consists of a system call, but if you say Y to "/proc
169 file system support", a tree of modifiable sysctl entries will be
170 generated beneath the /proc/sys directory. They are explained in the
171 files in <file:Documentation/sysctl/>. Note that enabling this
172 option will enlarge the kernel by at least 8 KB.
173
174 As it is generally a good thing, you should say Y here unless
175 building a kernel for install/rescue disks or your system is very
176 limited in memory.
177
178config AUDIT
179 bool "Auditing support"
180 depends on NET
181 help
182 Enable auditing infrastructure that can be used with another
183 kernel subsystem, such as SELinux (which requires this for
184 logging of avc messages output). Does not do system-call
185 auditing without CONFIG_AUDITSYSCALL.
186
187config AUDITSYSCALL
188 bool "Enable system-call auditing support"
189 depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64)
190 default y if SECURITY_SELINUX
191 help
192 Enable low-overhead system-call auditing infrastructure that
193 can be used independently or with another kernel subsystem,
194 such as SELinux. To use audit's filesystem watch feature, please
195 ensure that INOTIFY is configured.
196
197config IKCONFIG
198 bool "Kernel .config support"
199 ---help---
200 This option enables the complete Linux kernel ".config" file
201 contents to be saved in the kernel. It provides documentation
202 of which kernel options are used in a running kernel or in an
203 on-disk kernel. This information can be extracted from the kernel
204 image file with the script scripts/extract-ikconfig and used as
205 input to rebuild the current kernel or to build another kernel.
206 It can also be extracted from a running kernel by reading
207 /proc/config.gz if enabled (below).
208
209config IKCONFIG_PROC
210 bool "Enable access to .config through /proc/config.gz"
211 depends on IKCONFIG && PROC_FS
212 ---help---
213 This option enables access to the kernel configuration file
214 through /proc/config.gz.
215
216config CPUSETS
217 bool "Cpuset support"
218 depends on SMP
219 help
220 This option will let you create and manage CPUSETs which
221 allow dynamically partitioning a system into sets of CPUs and
222 Memory Nodes and assigning tasks to run only within those sets.
223 This is primarily useful on large SMP or NUMA systems.
224
225 Say N if unsure.
226
227config RELAY
228 bool "Kernel->user space relay support (formerly relayfs)"
229 help
230 This option enables support for relay interface support in
231 certain file systems (such as debugfs).
232 It is designed to provide an efficient mechanism for tools and
233 facilities to relay large amounts of data from kernel space to
234 user space.
235
236 If unsure, say N.
237
238source "usr/Kconfig"
239
240config UID16
241 bool "Enable 16-bit UID system calls" if EMBEDDED
242 depends on ARM || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION)
243 default y
244 help
245 This enables the legacy 16-bit UID syscall wrappers.
246
247config CC_OPTIMIZE_FOR_SIZE
248 bool "Optimize for size (Look out for broken compilers!)"
249 default y
250 depends on ARM || H8300 || EXPERIMENTAL
251 help
252 Enabling this option will pass "-Os" instead of "-O2" to gcc
253 resulting in a smaller kernel.
254
255 WARNING: some versions of gcc may generate incorrect code with this
256 option. If problems are observed, a gcc upgrade may be needed.
257
258 If unsure, say N.
259
260menuconfig EMBEDDED
261 bool "Configure standard kernel features (for small systems)"
262 help
263 This option allows certain base kernel options and settings
264 to be disabled or tweaked. This is for specialized
265 environments which can tolerate a "non-standard" kernel.
266 Only use this if you really know what you are doing.
267
268config KALLSYMS
269 bool "Load all symbols for debugging/kksymoops" if EMBEDDED
270 default y
271 help
272 Say Y here to let the kernel print out symbolic crash information and
273 symbolic stack backtraces. This increases the size of the kernel
274 somewhat, as all symbols have to be loaded into the kernel image.
275
276config KALLSYMS_ALL
277 bool "Include all symbols in kallsyms"
278 depends on DEBUG_KERNEL && KALLSYMS
279 help
280 Normally kallsyms only contains the symbols of functions, for nicer
281 OOPS messages. Some debuggers can use kallsyms for other
282 symbols too: say Y here to include all symbols, if you need them
283 and you don't care about adding 300k to the size of your kernel.
284
285 Say N.
286
287config KALLSYMS_EXTRA_PASS
288 bool "Do an extra kallsyms pass"
289 depends on KALLSYMS
290 help
291 If kallsyms is not working correctly, the build will fail with
292 inconsistent kallsyms data. If that occurs, log a bug report and
293 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
294 Always say N here unless you find a bug in kallsyms, which must be
295 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
296 you wait for kallsyms to be fixed.
297
298
299config HOTPLUG
300 bool "Support for hot-pluggable devices" if EMBEDDED
301 default y
302 help
303 This option is provided for the case where no hotplug or uevent
304 capabilities is wanted by the kernel. You should only consider
305 disabling this option for embedded systems that do not use modules, a
306 dynamic /dev tree, or dynamic device discovery. Just say Y.
307
308config PRINTK
309 default y
310 bool "Enable support for printk" if EMBEDDED
311 help
312 This option enables normal printk support. Removing it
313 eliminates most of the message strings from the kernel image
314 and makes the kernel more or less silent. As this makes it
315 very difficult to diagnose system problems, saying N here is
316 strongly discouraged.
317
318config BUG
319 bool "BUG() support" if EMBEDDED
320 default y
321 help
322 Disabling this option eliminates support for BUG and WARN, reducing
323 the size of your kernel image and potentially quietly ignoring
324 numerous fatal conditions. You should only consider disabling this
325 option for embedded systems with no facilities for reporting errors.
326 Just say Y.
327
328config ELF_CORE
329 default y
330 bool "Enable ELF core dumps" if EMBEDDED
331 help
332 Enable support for generating core dumps. Disabling saves about 4k.
333
334config BASE_FULL
335 default y
336 bool "Enable full-sized data structures for core" if EMBEDDED
337 help
338 Disabling this option reduces the size of miscellaneous core
339 kernel data structures. This saves memory on small machines,
340 but may reduce performance.
341
342config FUTEX
343 bool "Enable futex support" if EMBEDDED
344 default y
345 help
346 Disabling this option will cause the kernel to be built without
347 support for "fast userspace mutexes". The resulting kernel may not
348 run glibc-based applications correctly.
349
350config EPOLL
351 bool "Enable eventpoll support" if EMBEDDED
352 default y
353 help
354 Disabling this option will cause the kernel to be built without
355 support for epoll family of system calls.
356
357config SHMEM
358 bool "Use full shmem filesystem" if EMBEDDED
359 default y
360 depends on MMU
361 help
362 The shmem is an internal filesystem used to manage shared memory.
363 It is backed by swap and manages resource limits. It is also exported
364 to userspace as tmpfs if TMPFS is enabled. Disabling this
365 option replaces shmem and tmpfs with the much simpler ramfs code,
366 which may be appropriate on small systems without swap.
367
368config SLAB
369 default y
370 bool "Use full SLAB allocator" if EMBEDDED
371 help
372 Disabling this replaces the advanced SLAB allocator and
373 kmalloc support with the drastically simpler SLOB allocator.
374 SLOB is more space efficient but does not scale well and is
375 more susceptible to fragmentation.
376
377endmenu # General setup
378
379config TINY_SHMEM
380 default !SHMEM
381 bool
382
383config BASE_SMALL
384 int
385 default 0 if BASE_FULL
386 default 1 if !BASE_FULL
387
388config SLOB
389 default !SLAB
390 bool
391
392menu "Loadable module support"
393
394config MODULES
395 bool "Enable loadable module support"
396 help
397 Kernel modules are small pieces of compiled code which can
398 be inserted in the running kernel, rather than being
399 permanently built into the kernel. You use the "modprobe"
400 tool to add (and sometimes remove) them. If you say Y here,
401 many parts of the kernel can be built as modules (by
402 answering M instead of Y where indicated): this is most
403 useful for infrequently used options which are not required
404 for booting. For more information, see the man pages for
405 modprobe, lsmod, modinfo, insmod and rmmod.
406
407 If you say Y here, you will need to run "make
408 modules_install" to put the modules under /lib/modules/
409 where modprobe can find them (you may need to be root to do
410 this).
411
412 If unsure, say Y.
413
414config MODULE_UNLOAD
415 bool "Module unloading"
416 depends on MODULES
417 help
418 Without this option you will not be able to unload any
419 modules (note that some modules may not be unloadable
420 anyway), which makes your kernel slightly smaller and
421 simpler. If unsure, say Y.
422
423config MODULE_FORCE_UNLOAD
424 bool "Forced module unloading"
425 depends on MODULE_UNLOAD && EXPERIMENTAL
426 help
427 This option allows you to force a module to unload, even if the
428 kernel believes it is unsafe: the kernel will remove the module
429 without waiting for anyone to stop using it (using the -f option to
430 rmmod). This is mainly for kernel developers and desperate users.
431 If unsure, say N.
432
433config MODVERSIONS
434 bool "Module versioning support"
435 depends on MODULES
436 help
437 Usually, you have to use modules compiled with your kernel.
438 Saying Y here makes it sometimes possible to use modules
439 compiled for different kernels, by adding enough information
440 to the modules to (hopefully) spot any changes which would
441 make them incompatible with the kernel you are running. If
442 unsure, say N.
443
444config MODULE_SRCVERSION_ALL
445 bool "Source checksum for all modules"
446 depends on MODULES
447 help
448 Modules which contain a MODULE_VERSION get an extra "srcversion"
449 field inserted into their modinfo section, which contains a
450 sum of the source files which made it. This helps maintainers
451 see exactly which source was used to build a module (since
452 others sometimes change the module source without updating
453 the version). With this option, such a "srcversion" field
454 will be created for all modules. If unsure, say N.
455
456config KMOD
457 bool "Automatic kernel module loading"
458 depends on MODULES
459 help
460 Normally when you have selected some parts of the kernel to
461 be created as kernel modules, you must load them (using the
462 "modprobe" command) before you can use them. If you say Y
463 here, some parts of the kernel will be able to load modules
464 automatically: when a part of the kernel needs a module, it
465 runs modprobe with the appropriate arguments, thereby
466 loading the module if it is available. If unsure, say Y.
467
468config STOP_MACHINE
469 bool
470 default y
471 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
472 help
473 Need stop_machine() primitive.
474endmenu
475
476menu "Block layer"
477source "block/Kconfig"
478endmenu