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1menu "Code maturity level options"
2
3config EXPERIMENTAL
4 bool "Prompt for development and/or incomplete code/drivers"
5 ---help---
6 Some of the various things that Linux supports (such as network
7 drivers, file systems, network protocols, etc.) can be in a state
8 of development where the functionality, stability, or the level of
9 testing is not yet high enough for general use. This is usually
10 known as the "alpha-test" phase among developers. If a feature is
11 currently in alpha-test, then the developers usually discourage
12 uninformed widespread use of this feature by the general public to
13 avoid "Why doesn't this work?" type mail messages. However, active
14 testing and use of these systems is welcomed. Just be aware that it
15 may not meet the normal level of reliability or it may fail to work
16 in some special cases. Detailed bug reports from people familiar
17 with the kernel internals are usually welcomed by the developers
18 (before submitting bug reports, please read the documents
19 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
20 <file:Documentation/BUG-HUNTING>, and
21 <file:Documentation/oops-tracing.txt> in the kernel source).
22
23 This option will also make obsoleted drivers available. These are
24 drivers that have been replaced by something else, and/or are
25 scheduled to be removed in a future kernel release.
26
27 Unless you intend to help test and develop a feature or driver that
28 falls into this category, or you have a situation that requires
29 using these features, you should probably say N here, which will
30 cause the configurator to present you with fewer choices. If
31 you say Y here, you will be offered the choice of using features or
32 drivers that are currently considered to be in the alpha-test phase.
33
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34config BROKEN
35 bool
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36
37config BROKEN_ON_SMP
38 bool
39 depends on BROKEN || !SMP
40 default y
41
42config LOCK_KERNEL
43 bool
44 depends on SMP || PREEMPT
45 default y
46
47config INIT_ENV_ARG_LIMIT
48 int
49 default 32 if !USERMODE
50 default 128 if USERMODE
51 help
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52 Maximum of each of the number of arguments and environment
53 variables passed to init from the kernel command line.
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54
55endmenu
56
57menu "General setup"
58
59config LOCALVERSION
60 string "Local version - append to kernel release"
61 help
62 Append an extra string to the end of your kernel version.
63 This will show up when you type uname, for example.
64 The string you set here will be appended after the contents of
65 any files with a filename matching localversion* in your
66 object and source tree, in that order. Your total string can
67 be a maximum of 64 characters.
68
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69config LOCALVERSION_AUTO
70 bool "Automatically append version information to the version string"
71 default y
72 help
73 This will try to automatically determine if the current tree is a
74 release tree by looking for git tags that
75 belong to the current top of tree revision.
76
77 A string of the format -gxxxxxxxx will be added to the localversion
78 if a git based tree is found. The string generated by this will be
79 appended after any matching localversion* files, and after the value
80 set in CONFIG_LOCALVERSION
81
82 Note: This requires Perl, and a git repository, but not necessarily
83 the git or cogito tools to be installed.
84
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85config SWAP
86 bool "Support for paging of anonymous memory (swap)"
87 depends on MMU
88 default y
89 help
90 This option allows you to choose whether you want to have support
92c3504e 91 for so called swap devices or swap files in your kernel that are
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92 used to provide more virtual memory than the actual RAM present
93 in your computer. If unsure say Y.
94
95config SYSVIPC
96 bool "System V IPC"
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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
106 You can find documentation about IPC with "info ipc" and also in
107 section 6.4 of the Linux Programmer's Guide, available from
108 <http://www.tldp.org/guides.html>.
109
110config POSIX_MQUEUE
111 bool "POSIX Message Queues"
112 depends on NET && EXPERIMENTAL
113 ---help---
114 POSIX variant of message queues is a part of IPC. In POSIX message
115 queues every message has a priority which decides about succession
116 of receiving it by a process. If you want to compile and run
117 programs written e.g. for Solaris with use of its POSIX message
118 queues (functions mq_*) say Y here. To use this feature you will
119 also need mqueue library, available from
120 <http://www.mat.uni.torun.pl/~wrona/posix_ipc/>
121
122 POSIX message queues are visible as a filesystem called 'mqueue'
123 and can be mounted somewhere if you want to do filesystem
124 operations on message queues.
125
126 If unsure, say Y.
127
128config BSD_PROCESS_ACCT
129 bool "BSD Process Accounting"
130 help
131 If you say Y here, a user level program will be able to instruct the
132 kernel (via a special system call) to write process accounting
133 information to a file: whenever a process exits, information about
134 that process will be appended to the file by the kernel. The
135 information includes things such as creation time, owning user,
136 command name, memory usage, controlling terminal etc. (the complete
137 list is in the struct acct in <file:include/linux/acct.h>). It is
138 up to the user level program to do useful things with this
139 information. This is generally a good idea, so say Y.
140
141config BSD_PROCESS_ACCT_V3
142 bool "BSD Process Accounting version 3 file format"
143 depends on BSD_PROCESS_ACCT
144 default n
145 help
146 If you say Y here, the process accounting information is written
147 in a new file format that also logs the process IDs of each
148 process and it's parent. Note that this file format is incompatible
149 with previous v0/v1/v2 file formats, so you will need updated tools
150 for processing it. A preliminary version of these tools is available
151 at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>.
152
153config SYSCTL
154 bool "Sysctl support"
155 ---help---
156 The sysctl interface provides a means of dynamically changing
157 certain kernel parameters and variables on the fly without requiring
158 a recompile of the kernel or reboot of the system. The primary
159 interface consists of a system call, but if you say Y to "/proc
160 file system support", a tree of modifiable sysctl entries will be
161 generated beneath the /proc/sys directory. They are explained in the
162 files in <file:Documentation/sysctl/>. Note that enabling this
163 option will enlarge the kernel by at least 8 KB.
164
165 As it is generally a good thing, you should say Y here unless
166 building a kernel for install/rescue disks or your system is very
167 limited in memory.
168
169config AUDIT
170 bool "Auditing support"
804a6a49 171 depends on NET
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172 help
173 Enable auditing infrastructure that can be used with another
174 kernel subsystem, such as SELinux (which requires this for
175 logging of avc messages output). Does not do system-call
176 auditing without CONFIG_AUDITSYSCALL.
177
178config AUDITSYSCALL
179 bool "Enable system-call auditing support"
347a8dc3 180 depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64)
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181 default y if SECURITY_SELINUX
182 help
183 Enable low-overhead system-call auditing infrastructure that
184 can be used independently or with another kernel subsystem,
185 such as SELinux.
186
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187config IKCONFIG
188 bool "Kernel .config support"
189 ---help---
190 This option enables the complete Linux kernel ".config" file
191 contents to be saved in the kernel. It provides documentation
192 of which kernel options are used in a running kernel or in an
193 on-disk kernel. This information can be extracted from the kernel
194 image file with the script scripts/extract-ikconfig and used as
195 input to rebuild the current kernel or to build another kernel.
196 It can also be extracted from a running kernel by reading
197 /proc/config.gz if enabled (below).
198
199config IKCONFIG_PROC
200 bool "Enable access to .config through /proc/config.gz"
201 depends on IKCONFIG && PROC_FS
202 ---help---
203 This option enables access to the kernel configuration file
204 through /proc/config.gz.
205
206config CPUSETS
207 bool "Cpuset support"
208 depends on SMP
209 help
d9fd8a6d 210 This option will let you create and manage CPUSETs which
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211 allow dynamically partitioning a system into sets of CPUs and
212 Memory Nodes and assigning tasks to run only within those sets.
213 This is primarily useful on large SMP or NUMA systems.
214
215 Say N if unsure.
216
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217config RELAY
218 bool "Kernel->user space relay support (formerly relayfs)"
219 help
220 This option enables support for relay interface support in
221 certain file systems (such as debugfs).
222 It is designed to provide an efficient mechanism for tools and
223 facilities to relay large amounts of data from kernel space to
224 user space.
225
226 If unsure, say N.
227
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228source "usr/Kconfig"
229
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230config UID16
231 bool "Enable 16-bit UID system calls" if EMBEDDED
2308acca 232 depends on ARM || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION)
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233 default y
234 help
235 This enables the legacy 16-bit UID syscall wrappers.
236
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237config VM86
238 depends X86
239 default y
240 bool "Enable VM86 support" if EMBEDDED
241 help
242 This option is required by programs like DOSEMU to run 16-bit legacy
243 code on X86 processors. It also may be needed by software like
244 XFree86 to initialize some video cards via BIOS. Disabling this
245 option saves about 6k.
246
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247config CC_OPTIMIZE_FOR_SIZE
248 bool "Optimize for size (Look out for broken compilers!)"
249 default y
250 depends on ARM || H8300 || EXPERIMENTAL
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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
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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
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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.
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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
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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
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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
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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
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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
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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
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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
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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
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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
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388config SLOB
389 default !SLAB
390 bool
391
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392config OBSOLETE_INTERMODULE
393 tristate
394
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395menu "Loadable module support"
396
397config MODULES
398 bool "Enable loadable module support"
399 help
400 Kernel modules are small pieces of compiled code which can
401 be inserted in the running kernel, rather than being
402 permanently built into the kernel. You use the "modprobe"
403 tool to add (and sometimes remove) them. If you say Y here,
404 many parts of the kernel can be built as modules (by
405 answering M instead of Y where indicated): this is most
406 useful for infrequently used options which are not required
407 for booting. For more information, see the man pages for
408 modprobe, lsmod, modinfo, insmod and rmmod.
409
410 If you say Y here, you will need to run "make
411 modules_install" to put the modules under /lib/modules/
412 where modprobe can find them (you may need to be root to do
413 this).
414
415 If unsure, say Y.
416
417config MODULE_UNLOAD
418 bool "Module unloading"
419 depends on MODULES
420 help
421 Without this option you will not be able to unload any
422 modules (note that some modules may not be unloadable
423 anyway), which makes your kernel slightly smaller and
424 simpler. If unsure, say Y.
425
426config MODULE_FORCE_UNLOAD
427 bool "Forced module unloading"
428 depends on MODULE_UNLOAD && EXPERIMENTAL
429 help
430 This option allows you to force a module to unload, even if the
431 kernel believes it is unsafe: the kernel will remove the module
432 without waiting for anyone to stop using it (using the -f option to
433 rmmod). This is mainly for kernel developers and desperate users.
434 If unsure, say N.
435
1da177e4 436config MODVERSIONS
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437 bool "Module versioning support"
438 depends on MODULES
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439 help
440 Usually, you have to use modules compiled with your kernel.
441 Saying Y here makes it sometimes possible to use modules
442 compiled for different kernels, by adding enough information
443 to the modules to (hopefully) spot any changes which would
444 make them incompatible with the kernel you are running. If
445 unsure, say N.
446
447config MODULE_SRCVERSION_ALL
448 bool "Source checksum for all modules"
449 depends on MODULES
450 help
451 Modules which contain a MODULE_VERSION get an extra "srcversion"
452 field inserted into their modinfo section, which contains a
453 sum of the source files which made it. This helps maintainers
454 see exactly which source was used to build a module (since
455 others sometimes change the module source without updating
456 the version). With this option, such a "srcversion" field
457 will be created for all modules. If unsure, say N.
458
459config KMOD
460 bool "Automatic kernel module loading"
461 depends on MODULES
462 help
463 Normally when you have selected some parts of the kernel to
464 be created as kernel modules, you must load them (using the
465 "modprobe" command) before you can use them. If you say Y
466 here, some parts of the kernel will be able to load modules
467 automatically: when a part of the kernel needs a module, it
468 runs modprobe with the appropriate arguments, thereby
469 loading the module if it is available. If unsure, say Y.
470
471config STOP_MACHINE
472 bool
473 default y
474 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
475 help
476 Need stop_machine() primitive.
477endmenu
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478
479menu "Block layer"
480source "block/Kconfig"
481endmenu