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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24 drivers that have been replaced by something else, and/or are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
34config CLEAN_COMPILE
35 bool "Select only drivers expected to compile cleanly" if EXPERIMENTAL
36 default y
37 help
38 Select this option if you don't even want to see the option
39 to configure known-broken drivers.
40
41 If unsure, say Y
42
43config BROKEN
44 bool
45 depends on !CLEAN_COMPILE
46 default y
47
48config BROKEN_ON_SMP
49 bool
50 depends on BROKEN || !SMP
51 default y
52
53config LOCK_KERNEL
54 bool
55 depends on SMP || PREEMPT
56 default y
57
58config INIT_ENV_ARG_LIMIT
59 int
60 default 32 if !USERMODE
61 default 128 if USERMODE
62 help
63 This is the value of the two limits on the number of argument and of
64 env.var passed to init from the kernel command line.
65
66endmenu
67
68menu "General setup"
69
70config LOCALVERSION
71 string "Local version - append to kernel release"
72 help
73 Append an extra string to the end of your kernel version.
74 This will show up when you type uname, for example.
75 The string you set here will be appended after the contents of
76 any files with a filename matching localversion* in your
77 object and source tree, in that order. Your total string can
78 be a maximum of 64 characters.
79
80config SWAP
81 bool "Support for paging of anonymous memory (swap)"
82 depends on MMU
83 default y
84 help
85 This option allows you to choose whether you want to have support
86 for socalled swap devices or swap files in your kernel that are
87 used to provide more virtual memory than the actual RAM present
88 in your computer. If unsure say Y.
89
90config SYSVIPC
91 bool "System V IPC"
92 depends on MMU
93 ---help---
94 Inter Process Communication is a suite of library functions and
95 system calls which let processes (running programs) synchronize and
96 exchange information. It is generally considered to be a good thing,
97 and some programs won't run unless you say Y here. In particular, if
98 you want to run the DOS emulator dosemu under Linux (read the
99 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
100 you'll need to say Y here.
101
102 You can find documentation about IPC with "info ipc" and also in
103 section 6.4 of the Linux Programmer's Guide, available from
104 <http://www.tldp.org/guides.html>.
105
106config POSIX_MQUEUE
107 bool "POSIX Message Queues"
108 depends on NET && EXPERIMENTAL
109 ---help---
110 POSIX variant of message queues is a part of IPC. In POSIX message
111 queues every message has a priority which decides about succession
112 of receiving it by a process. If you want to compile and run
113 programs written e.g. for Solaris with use of its POSIX message
114 queues (functions mq_*) say Y here. To use this feature you will
115 also need mqueue library, available from
116 <http://www.mat.uni.torun.pl/~wrona/posix_ipc/>
117
118 POSIX message queues are visible as a filesystem called 'mqueue'
119 and can be mounted somewhere if you want to do filesystem
120 operations on message queues.
121
122 If unsure, say Y.
123
124config BSD_PROCESS_ACCT
125 bool "BSD Process Accounting"
126 help
127 If you say Y here, a user level program will be able to instruct the
128 kernel (via a special system call) to write process accounting
129 information to a file: whenever a process exits, information about
130 that process will be appended to the file by the kernel. The
131 information includes things such as creation time, owning user,
132 command name, memory usage, controlling terminal etc. (the complete
133 list is in the struct acct in <file:include/linux/acct.h>). It is
134 up to the user level program to do useful things with this
135 information. This is generally a good idea, so say Y.
136
137config BSD_PROCESS_ACCT_V3
138 bool "BSD Process Accounting version 3 file format"
139 depends on BSD_PROCESS_ACCT
140 default n
141 help
142 If you say Y here, the process accounting information is written
143 in a new file format that also logs the process IDs of each
144 process and it's parent. Note that this file format is incompatible
145 with previous v0/v1/v2 file formats, so you will need updated tools
146 for processing it. A preliminary version of these tools is available
147 at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>.
148
149config SYSCTL
150 bool "Sysctl support"
151 ---help---
152 The sysctl interface provides a means of dynamically changing
153 certain kernel parameters and variables on the fly without requiring
154 a recompile of the kernel or reboot of the system. The primary
155 interface consists of a system call, but if you say Y to "/proc
156 file system support", a tree of modifiable sysctl entries will be
157 generated beneath the /proc/sys directory. They are explained in the
158 files in <file:Documentation/sysctl/>. Note that enabling this
159 option will enlarge the kernel by at least 8 KB.
160
161 As it is generally a good thing, you should say Y here unless
162 building a kernel for install/rescue disks or your system is very
163 limited in memory.
164
165config AUDIT
166 bool "Auditing support"
804a6a49 167 depends on NET
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168 default y if SECURITY_SELINUX
169 help
170 Enable auditing infrastructure that can be used with another
171 kernel subsystem, such as SELinux (which requires this for
172 logging of avc messages output). Does not do system-call
173 auditing without CONFIG_AUDITSYSCALL.
174
175config AUDITSYSCALL
176 bool "Enable system-call auditing support"
f7ceba36 177 depends on AUDIT && (X86 || PPC || PPC64 || ARCH_S390 || IA64 || UML || SPARC64)
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178 default y if SECURITY_SELINUX
179 help
180 Enable low-overhead system-call auditing infrastructure that
181 can be used independently or with another kernel subsystem,
182 such as SELinux.
183
184config HOTPLUG
185 bool "Support for hot-pluggable devices" if !ARCH_S390
186 default ARCH_S390
187 help
188 This option is provided for the case where no in-kernel-tree
189 modules require HOTPLUG functionality, but a module built
190 outside the kernel tree does. Such modules require Y here.
191
192config KOBJECT_UEVENT
193 bool "Kernel Userspace Events"
194 depends on NET
195 default y
196 help
197 This option enables the kernel userspace event layer, which is a
198 simple mechanism for kernel-to-user communication over a netlink
199 socket.
200 The goal of the kernel userspace events layer is to provide a simple
201 and efficient events system, that notifies userspace about kobject
202 state changes. This will enable applications to just listen for
203 events instead of polling system devices and files.
204 Hotplug events (kobject addition and removal) are also available on
205 the netlink socket in addition to the execution of /sbin/hotplug if
206 CONFIG_HOTPLUG is enabled.
207
208 Say Y, unless you are building a system requiring minimal memory
209 consumption.
210
211config IKCONFIG
212 bool "Kernel .config support"
213 ---help---
214 This option enables the complete Linux kernel ".config" file
215 contents to be saved in the kernel. It provides documentation
216 of which kernel options are used in a running kernel or in an
217 on-disk kernel. This information can be extracted from the kernel
218 image file with the script scripts/extract-ikconfig and used as
219 input to rebuild the current kernel or to build another kernel.
220 It can also be extracted from a running kernel by reading
221 /proc/config.gz if enabled (below).
222
223config IKCONFIG_PROC
224 bool "Enable access to .config through /proc/config.gz"
225 depends on IKCONFIG && PROC_FS
226 ---help---
227 This option enables access to the kernel configuration file
228 through /proc/config.gz.
229
230config CPUSETS
231 bool "Cpuset support"
232 depends on SMP
233 help
234 This options will let you create and manage CPUSET's which
235 allow dynamically partitioning a system into sets of CPUs and
236 Memory Nodes and assigning tasks to run only within those sets.
237 This is primarily useful on large SMP or NUMA systems.
238
239 Say N if unsure.
240
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241source "usr/Kconfig"
242
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243menuconfig EMBEDDED
244 bool "Configure standard kernel features (for small systems)"
245 help
246 This option allows certain base kernel options and settings
247 to be disabled or tweaked. This is for specialized
248 environments which can tolerate a "non-standard" kernel.
249 Only use this if you really know what you are doing.
250
251config KALLSYMS
252 bool "Load all symbols for debugging/kksymoops" if EMBEDDED
253 default y
254 help
255 Say Y here to let the kernel print out symbolic crash information and
256 symbolic stack backtraces. This increases the size of the kernel
257 somewhat, as all symbols have to be loaded into the kernel image.
258
259config KALLSYMS_ALL
260 bool "Include all symbols in kallsyms"
261 depends on DEBUG_KERNEL && KALLSYMS
262 help
263 Normally kallsyms only contains the symbols of functions, for nicer
264 OOPS messages. Some debuggers can use kallsyms for other
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265 symbols too: say Y here to include all symbols, if you need them
266 and you don't care about adding 300k to the size of your kernel.
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267
268 Say N.
269
270config KALLSYMS_EXTRA_PASS
271 bool "Do an extra kallsyms pass"
272 depends on KALLSYMS
273 help
274 If kallsyms is not working correctly, the build will fail with
275 inconsistent kallsyms data. If that occurs, log a bug report and
276 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
277 Always say N here unless you find a bug in kallsyms, which must be
278 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
279 you wait for kallsyms to be fixed.
280
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281
282config PRINTK
283 default y
284 bool "Enable support for printk" if EMBEDDED
285 help
286 This option enables normal printk support. Removing it
287 eliminates most of the message strings from the kernel image
288 and makes the kernel more or less silent. As this makes it
289 very difficult to diagnose system problems, saying N here is
290 strongly discouraged.
291
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292config BUG
293 bool "BUG() support" if EMBEDDED
294 default y
295 help
296 Disabling this option eliminates support for BUG and WARN, reducing
297 the size of your kernel image and potentially quietly ignoring
298 numerous fatal conditions. You should only consider disabling this
299 option for embedded systems with no facilities for reporting errors.
300 Just say Y.
301
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302config BASE_FULL
303 default y
304 bool "Enable full-sized data structures for core" if EMBEDDED
305 help
306 Disabling this option reduces the size of miscellaneous core
307 kernel data structures. This saves memory on small machines,
308 but may reduce performance.
309
310config FUTEX
311 bool "Enable futex support" if EMBEDDED
312 default y
313 help
314 Disabling this option will cause the kernel to be built without
315 support for "fast userspace mutexes". The resulting kernel may not
316 run glibc-based applications correctly.
317
318config EPOLL
319 bool "Enable eventpoll support" if EMBEDDED
320 default y
321 help
322 Disabling this option will cause the kernel to be built without
323 support for epoll family of system calls.
324
325config CC_OPTIMIZE_FOR_SIZE
326 bool "Optimize for size" if EMBEDDED
327 default y if ARM || H8300
328 help
329 Enabling this option will pass "-Os" instead of "-O2" to gcc
330 resulting in a smaller kernel.
331
332 WARNING: some versions of gcc may generate incorrect code with this
333 option. If problems are observed, a gcc upgrade may be needed.
334
335 If unsure, say N.
336
337config SHMEM
338 bool "Use full shmem filesystem" if EMBEDDED
339 default y
340 depends on MMU
341 help
342 The shmem is an internal filesystem used to manage shared memory.
343 It is backed by swap and manages resource limits. It is also exported
344 to userspace as tmpfs if TMPFS is enabled. Disabling this
345 option replaces shmem and tmpfs with the much simpler ramfs code,
346 which may be appropriate on small systems without swap.
347
348config CC_ALIGN_FUNCTIONS
349 int "Function alignment" if EMBEDDED
350 default 0
351 help
352 Align the start of functions to the next power-of-two greater than n,
353 skipping up to n bytes. For instance, 32 aligns functions
354 to the next 32-byte boundary, but 24 would align to the next
355 32-byte boundary only if this can be done by skipping 23 bytes or less.
356 Zero means use compiler's default.
357
358config CC_ALIGN_LABELS
359 int "Label alignment" if EMBEDDED
360 default 0
361 help
362 Align all branch targets to a power-of-two boundary, skipping
363 up to n bytes like ALIGN_FUNCTIONS. This option can easily
364 make code slower, because it must insert dummy operations for
365 when the branch target is reached in the usual flow of the code.
366 Zero means use compiler's default.
367
368config CC_ALIGN_LOOPS
369 int "Loop alignment" if EMBEDDED
370 default 0
371 help
372 Align loops to a power-of-two boundary, skipping up to n bytes.
373 Zero means use compiler's default.
374
375config CC_ALIGN_JUMPS
376 int "Jump alignment" if EMBEDDED
377 default 0
378 help
379 Align branch targets to a power-of-two boundary, for branch
380 targets where the targets can only be reached by jumping,
381 skipping up to n bytes like ALIGN_FUNCTIONS. In this case,
382 no dummy operations need be executed.
383 Zero means use compiler's default.
384
385endmenu # General setup
386
387config TINY_SHMEM
388 default !SHMEM
389 bool
390
391config BASE_SMALL
392 int
393 default 0 if BASE_FULL
394 default 1 if !BASE_FULL
395
396menu "Loadable module support"
397
398config MODULES
399 bool "Enable loadable module support"
400 help
401 Kernel modules are small pieces of compiled code which can
402 be inserted in the running kernel, rather than being
403 permanently built into the kernel. You use the "modprobe"
404 tool to add (and sometimes remove) them. If you say Y here,
405 many parts of the kernel can be built as modules (by
406 answering M instead of Y where indicated): this is most
407 useful for infrequently used options which are not required
408 for booting. For more information, see the man pages for
409 modprobe, lsmod, modinfo, insmod and rmmod.
410
411 If you say Y here, you will need to run "make
412 modules_install" to put the modules under /lib/modules/
413 where modprobe can find them (you may need to be root to do
414 this).
415
416 If unsure, say Y.
417
418config MODULE_UNLOAD
419 bool "Module unloading"
420 depends on MODULES
421 help
422 Without this option you will not be able to unload any
423 modules (note that some modules may not be unloadable
424 anyway), which makes your kernel slightly smaller and
425 simpler. If unsure, say Y.
426
427config MODULE_FORCE_UNLOAD
428 bool "Forced module unloading"
429 depends on MODULE_UNLOAD && EXPERIMENTAL
430 help
431 This option allows you to force a module to unload, even if the
432 kernel believes it is unsafe: the kernel will remove the module
433 without waiting for anyone to stop using it (using the -f option to
434 rmmod). This is mainly for kernel developers and desperate users.
435 If unsure, say N.
436
437config OBSOLETE_MODPARM
438 bool
439 default y
440 depends on MODULES
441 help
442 You need this option to use module parameters on modules which
443 have not been converted to the new module parameter system yet.
444 If unsure, say Y.
445
446config MODVERSIONS
447 bool "Module versioning support (EXPERIMENTAL)"
34a1a63e 448 depends on MODULES && EXPERIMENTAL
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449 help
450 Usually, you have to use modules compiled with your kernel.
451 Saying Y here makes it sometimes possible to use modules
452 compiled for different kernels, by adding enough information
453 to the modules to (hopefully) spot any changes which would
454 make them incompatible with the kernel you are running. If
455 unsure, say N.
456
457config MODULE_SRCVERSION_ALL
458 bool "Source checksum for all modules"
459 depends on MODULES
460 help
461 Modules which contain a MODULE_VERSION get an extra "srcversion"
462 field inserted into their modinfo section, which contains a
463 sum of the source files which made it. This helps maintainers
464 see exactly which source was used to build a module (since
465 others sometimes change the module source without updating
466 the version). With this option, such a "srcversion" field
467 will be created for all modules. If unsure, say N.
468
469config KMOD
470 bool "Automatic kernel module loading"
471 depends on MODULES
472 help
473 Normally when you have selected some parts of the kernel to
474 be created as kernel modules, you must load them (using the
475 "modprobe" command) before you can use them. If you say Y
476 here, some parts of the kernel will be able to load modules
477 automatically: when a part of the kernel needs a module, it
478 runs modprobe with the appropriate arguments, thereby
479 loading the module if it is available. If unsure, say Y.
480
481config STOP_MACHINE
482 bool
483 default y
484 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
485 help
486 Need stop_machine() primitive.
487endmenu