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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
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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32 drivers that have been replaced by something else, and/or are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
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42config BROKEN
43 bool
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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
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57 default 32 if !UML
58 default 128 if UML
1da177e4 59 help
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60 Maximum of each of the number of arguments and environment
61 variables passed to init from the kernel command line.
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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
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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
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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
92c3504e 99 for so called swap devices or swap files in your kernel that are
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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"
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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
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161config TASKSTATS
162 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
163 depends on NET
164 default n
165 help
166 Export selected statistics for tasks/processes through the
167 generic netlink interface. Unlike BSD process accounting, the
168 statistics are available during the lifetime of tasks/processes as
169 responses to commands. Like BSD accounting, they are sent to user
170 space on task exit.
171
172 Say N if unsure.
173
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174config TASK_DELAY_ACCT
175 bool "Enable per-task delay accounting (EXPERIMENTAL)"
6f44993f 176 depends on TASKSTATS
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177 help
178 Collect information on time spent by a task waiting for system
179 resources like cpu, synchronous block I/O completion and swapping
180 in pages. Such statistics can help in setting a task's priorities
181 relative to other tasks for cpu, io, rss limits etc.
182
183 Say N if unsure.
184
1da177e4 185config SYSCTL
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186 bool "Sysctl support" if EMBEDDED
187 default y
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188 ---help---
189 The sysctl interface provides a means of dynamically changing
190 certain kernel parameters and variables on the fly without requiring
191 a recompile of the kernel or reboot of the system. The primary
192 interface consists of a system call, but if you say Y to "/proc
193 file system support", a tree of modifiable sysctl entries will be
194 generated beneath the /proc/sys directory. They are explained in the
195 files in <file:Documentation/sysctl/>. Note that enabling this
196 option will enlarge the kernel by at least 8 KB.
197
198 As it is generally a good thing, you should say Y here unless
199 building a kernel for install/rescue disks or your system is very
200 limited in memory.
201
202config AUDIT
203 bool "Auditing support"
804a6a49 204 depends on NET
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205 help
206 Enable auditing infrastructure that can be used with another
207 kernel subsystem, such as SELinux (which requires this for
208 logging of avc messages output). Does not do system-call
209 auditing without CONFIG_AUDITSYSCALL.
210
211config AUDITSYSCALL
212 bool "Enable system-call auditing support"
347a8dc3 213 depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64)
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214 default y if SECURITY_SELINUX
215 help
216 Enable low-overhead system-call auditing infrastructure that
217 can be used independently or with another kernel subsystem,
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218 such as SELinux. To use audit's filesystem watch feature, please
219 ensure that INOTIFY is configured.
1da177e4 220
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221config IKCONFIG
222 bool "Kernel .config support"
223 ---help---
224 This option enables the complete Linux kernel ".config" file
225 contents to be saved in the kernel. It provides documentation
226 of which kernel options are used in a running kernel or in an
227 on-disk kernel. This information can be extracted from the kernel
228 image file with the script scripts/extract-ikconfig and used as
229 input to rebuild the current kernel or to build another kernel.
230 It can also be extracted from a running kernel by reading
231 /proc/config.gz if enabled (below).
232
233config IKCONFIG_PROC
234 bool "Enable access to .config through /proc/config.gz"
235 depends on IKCONFIG && PROC_FS
236 ---help---
237 This option enables access to the kernel configuration file
238 through /proc/config.gz.
239
240config CPUSETS
241 bool "Cpuset support"
242 depends on SMP
243 help
d9fd8a6d 244 This option will let you create and manage CPUSETs which
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245 allow dynamically partitioning a system into sets of CPUs and
246 Memory Nodes and assigning tasks to run only within those sets.
247 This is primarily useful on large SMP or NUMA systems.
248
249 Say N if unsure.
250
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251config RELAY
252 bool "Kernel->user space relay support (formerly relayfs)"
253 help
254 This option enables support for relay interface support in
255 certain file systems (such as debugfs).
256 It is designed to provide an efficient mechanism for tools and
257 facilities to relay large amounts of data from kernel space to
258 user space.
259
260 If unsure, say N.
261
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262source "usr/Kconfig"
263
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264config UID16
265 bool "Enable 16-bit UID system calls" if EMBEDDED
2308acca 266 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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267 default y
268 help
269 This enables the legacy 16-bit UID syscall wrappers.
270
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271config CC_OPTIMIZE_FOR_SIZE
272 bool "Optimize for size (Look out for broken compilers!)"
273 default y
274 depends on ARM || H8300 || EXPERIMENTAL
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275 help
276 Enabling this option will pass "-Os" instead of "-O2" to gcc
277 resulting in a smaller kernel.
278
279 WARNING: some versions of gcc may generate incorrect code with this
280 option. If problems are observed, a gcc upgrade may be needed.
281
282 If unsure, say N.
283
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284menuconfig EMBEDDED
285 bool "Configure standard kernel features (for small systems)"
286 help
287 This option allows certain base kernel options and settings
288 to be disabled or tweaked. This is for specialized
289 environments which can tolerate a "non-standard" kernel.
290 Only use this if you really know what you are doing.
291
292config KALLSYMS
293 bool "Load all symbols for debugging/kksymoops" if EMBEDDED
294 default y
295 help
296 Say Y here to let the kernel print out symbolic crash information and
297 symbolic stack backtraces. This increases the size of the kernel
298 somewhat, as all symbols have to be loaded into the kernel image.
299
300config KALLSYMS_ALL
301 bool "Include all symbols in kallsyms"
302 depends on DEBUG_KERNEL && KALLSYMS
303 help
304 Normally kallsyms only contains the symbols of functions, for nicer
305 OOPS messages. Some debuggers can use kallsyms for other
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306 symbols too: say Y here to include all symbols, if you need them
307 and you don't care about adding 300k to the size of your kernel.
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308
309 Say N.
310
311config KALLSYMS_EXTRA_PASS
312 bool "Do an extra kallsyms pass"
313 depends on KALLSYMS
314 help
315 If kallsyms is not working correctly, the build will fail with
316 inconsistent kallsyms data. If that occurs, log a bug report and
317 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
318 Always say N here unless you find a bug in kallsyms, which must be
319 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
320 you wait for kallsyms to be fixed.
321
d59745ce 322
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323config HOTPLUG
324 bool "Support for hot-pluggable devices" if EMBEDDED
325 default y
326 help
327 This option is provided for the case where no hotplug or uevent
328 capabilities is wanted by the kernel. You should only consider
329 disabling this option for embedded systems that do not use modules, a
330 dynamic /dev tree, or dynamic device discovery. Just say Y.
331
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332config PRINTK
333 default y
334 bool "Enable support for printk" if EMBEDDED
335 help
336 This option enables normal printk support. Removing it
337 eliminates most of the message strings from the kernel image
338 and makes the kernel more or less silent. As this makes it
339 very difficult to diagnose system problems, saying N here is
340 strongly discouraged.
341
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342config BUG
343 bool "BUG() support" if EMBEDDED
344 default y
345 help
346 Disabling this option eliminates support for BUG and WARN, reducing
347 the size of your kernel image and potentially quietly ignoring
348 numerous fatal conditions. You should only consider disabling this
349 option for embedded systems with no facilities for reporting errors.
350 Just say Y.
351
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352config ELF_CORE
353 default y
354 bool "Enable ELF core dumps" if EMBEDDED
355 help
356 Enable support for generating core dumps. Disabling saves about 4k.
357
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358config BASE_FULL
359 default y
360 bool "Enable full-sized data structures for core" if EMBEDDED
361 help
362 Disabling this option reduces the size of miscellaneous core
363 kernel data structures. This saves memory on small machines,
364 but may reduce performance.
365
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366config RT_MUTEXES
367 boolean
368 select PLIST
369
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370config FUTEX
371 bool "Enable futex support" if EMBEDDED
372 default y
23f78d4a 373 select RT_MUTEXES
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374 help
375 Disabling this option will cause the kernel to be built without
376 support for "fast userspace mutexes". The resulting kernel may not
377 run glibc-based applications correctly.
378
379config EPOLL
380 bool "Enable eventpoll support" if EMBEDDED
381 default y
382 help
383 Disabling this option will cause the kernel to be built without
384 support for epoll family of system calls.
385
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386config SHMEM
387 bool "Use full shmem filesystem" if EMBEDDED
388 default y
389 depends on MMU
390 help
391 The shmem is an internal filesystem used to manage shared memory.
392 It is backed by swap and manages resource limits. It is also exported
393 to userspace as tmpfs if TMPFS is enabled. Disabling this
394 option replaces shmem and tmpfs with the much simpler ramfs code,
395 which may be appropriate on small systems without swap.
396
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397config SLAB
398 default y
399 bool "Use full SLAB allocator" if EMBEDDED
400 help
401 Disabling this replaces the advanced SLAB allocator and
402 kmalloc support with the drastically simpler SLOB allocator.
403 SLOB is more space efficient but does not scale well and is
404 more susceptible to fragmentation.
405
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406config VM_EVENT_COUNTERS
407 default y
408 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
409 help
410 VM event counters are only needed to for event counts to be
411 shown. They have no function for the kernel itself. This
412 option allows the disabling of the VM event counters.
413 /proc/vmstat will only show page counts.
414
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415endmenu # General setup
416
417config TINY_SHMEM
418 default !SHMEM
419 bool
420
421config BASE_SMALL
422 int
423 default 0 if BASE_FULL
424 default 1 if !BASE_FULL
425
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426config SLOB
427 default !SLAB
428 bool
429
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430menu "Loadable module support"
431
432config MODULES
433 bool "Enable loadable module support"
434 help
435 Kernel modules are small pieces of compiled code which can
436 be inserted in the running kernel, rather than being
437 permanently built into the kernel. You use the "modprobe"
438 tool to add (and sometimes remove) them. If you say Y here,
439 many parts of the kernel can be built as modules (by
440 answering M instead of Y where indicated): this is most
441 useful for infrequently used options which are not required
442 for booting. For more information, see the man pages for
443 modprobe, lsmod, modinfo, insmod and rmmod.
444
445 If you say Y here, you will need to run "make
446 modules_install" to put the modules under /lib/modules/
447 where modprobe can find them (you may need to be root to do
448 this).
449
450 If unsure, say Y.
451
452config MODULE_UNLOAD
453 bool "Module unloading"
454 depends on MODULES
455 help
456 Without this option you will not be able to unload any
457 modules (note that some modules may not be unloadable
458 anyway), which makes your kernel slightly smaller and
459 simpler. If unsure, say Y.
460
461config MODULE_FORCE_UNLOAD
462 bool "Forced module unloading"
463 depends on MODULE_UNLOAD && EXPERIMENTAL
464 help
465 This option allows you to force a module to unload, even if the
466 kernel believes it is unsafe: the kernel will remove the module
467 without waiting for anyone to stop using it (using the -f option to
468 rmmod). This is mainly for kernel developers and desperate users.
469 If unsure, say N.
470
1da177e4 471config MODVERSIONS
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472 bool "Module versioning support"
473 depends on MODULES
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474 help
475 Usually, you have to use modules compiled with your kernel.
476 Saying Y here makes it sometimes possible to use modules
477 compiled for different kernels, by adding enough information
478 to the modules to (hopefully) spot any changes which would
479 make them incompatible with the kernel you are running. If
480 unsure, say N.
481
482config MODULE_SRCVERSION_ALL
483 bool "Source checksum for all modules"
484 depends on MODULES
485 help
486 Modules which contain a MODULE_VERSION get an extra "srcversion"
487 field inserted into their modinfo section, which contains a
488 sum of the source files which made it. This helps maintainers
489 see exactly which source was used to build a module (since
490 others sometimes change the module source without updating
491 the version). With this option, such a "srcversion" field
492 will be created for all modules. If unsure, say N.
493
494config KMOD
495 bool "Automatic kernel module loading"
496 depends on MODULES
497 help
498 Normally when you have selected some parts of the kernel to
499 be created as kernel modules, you must load them (using the
500 "modprobe" command) before you can use them. If you say Y
501 here, some parts of the kernel will be able to load modules
502 automatically: when a part of the kernel needs a module, it
503 runs modprobe with the appropriate arguments, thereby
504 loading the module if it is available. If unsure, say Y.
505
506config STOP_MACHINE
507 bool
508 default y
509 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
510 help
511 Need stop_machine() primitive.
512endmenu
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513
514menu "Block layer"
515source "block/Kconfig"
516endmenu