tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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24 drivers that have been replaced by something else, and/or are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 Maximum of each of the number of arguments and environment
64 variables 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 LOCALVERSION_AUTO
81 bool "Automatically append version information to the version string"
82 default y
83 help
84 This will try to automatically determine if the current tree is a
85 release tree by looking for git tags that
86 belong to the current top of tree revision.
87
88 A string of the format -gxxxxxxxx will be added to the localversion
89 if a git based tree is found. The string generated by this will be
90 appended after any matching localversion* files, and after the value
91 set in CONFIG_LOCALVERSION
92
93 Note: This requires Perl, and a git repository, but not necessarily
94 the git or cogito tools to be installed.
95
96config SWAP
97 bool "Support for paging of anonymous memory (swap)"
98 depends on MMU
99 default y
100 help
101 This option allows you to choose whether you want to have support
102 for socalled swap devices or swap files in your kernel that are
103 used to provide more virtual memory than the actual RAM present
104 in your computer. If unsure say Y.
105
106config SYSVIPC
107 bool "System V IPC"
108 depends on MMU
109 ---help---
110 Inter Process Communication is a suite of library functions and
111 system calls which let processes (running programs) synchronize and
112 exchange information. It is generally considered to be a good thing,
113 and some programs won't run unless you say Y here. In particular, if
114 you want to run the DOS emulator dosemu under Linux (read the
115 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
116 you'll need to say Y here.
117
118 You can find documentation about IPC with "info ipc" and also in
119 section 6.4 of the Linux Programmer's Guide, available from
120 <http://www.tldp.org/guides.html>.
121
122config POSIX_MQUEUE
123 bool "POSIX Message Queues"
124 depends on NET && EXPERIMENTAL
125 ---help---
126 POSIX variant of message queues is a part of IPC. In POSIX message
127 queues every message has a priority which decides about succession
128 of receiving it by a process. If you want to compile and run
129 programs written e.g. for Solaris with use of its POSIX message
130 queues (functions mq_*) say Y here. To use this feature you will
131 also need mqueue library, available from
132 <http://www.mat.uni.torun.pl/~wrona/posix_ipc/>
133
134 POSIX message queues are visible as a filesystem called 'mqueue'
135 and can be mounted somewhere if you want to do filesystem
136 operations on message queues.
137
138 If unsure, say Y.
139
140config BSD_PROCESS_ACCT
141 bool "BSD Process Accounting"
142 help
143 If you say Y here, a user level program will be able to instruct the
144 kernel (via a special system call) to write process accounting
145 information to a file: whenever a process exits, information about
146 that process will be appended to the file by the kernel. The
147 information includes things such as creation time, owning user,
148 command name, memory usage, controlling terminal etc. (the complete
149 list is in the struct acct in <file:include/linux/acct.h>). It is
150 up to the user level program to do useful things with this
151 information. This is generally a good idea, so say Y.
152
153config BSD_PROCESS_ACCT_V3
154 bool "BSD Process Accounting version 3 file format"
155 depends on BSD_PROCESS_ACCT
156 default n
157 help
158 If you say Y here, the process accounting information is written
159 in a new file format that also logs the process IDs of each
160 process and it's parent. Note that this file format is incompatible
161 with previous v0/v1/v2 file formats, so you will need updated tools
162 for processing it. A preliminary version of these tools is available
163 at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>.
164
165config SYSCTL
166 bool "Sysctl support"
167 ---help---
168 The sysctl interface provides a means of dynamically changing
169 certain kernel parameters and variables on the fly without requiring
170 a recompile of the kernel or reboot of the system. The primary
171 interface consists of a system call, but if you say Y to "/proc
172 file system support", a tree of modifiable sysctl entries will be
173 generated beneath the /proc/sys directory. They are explained in the
174 files in <file:Documentation/sysctl/>. Note that enabling this
175 option will enlarge the kernel by at least 8 KB.
176
177 As it is generally a good thing, you should say Y here unless
178 building a kernel for install/rescue disks or your system is very
179 limited in memory.
180
181config AUDIT
182 bool "Auditing support"
183 depends on NET
184 default y if SECURITY_SELINUX
185 help
186 Enable auditing infrastructure that can be used with another
187 kernel subsystem, such as SELinux (which requires this for
188 logging of avc messages output). Does not do system-call
189 auditing without CONFIG_AUDITSYSCALL.
190
191config AUDITSYSCALL
192 bool "Enable system-call auditing support"
193 depends on AUDIT && (X86 || PPC || PPC64 || ARCH_S390 || IA64 || UML || SPARC64)
194 default y if SECURITY_SELINUX
195 help
196 Enable low-overhead system-call auditing infrastructure that
197 can be used independently or with another kernel subsystem,
198 such as SELinux.
199
200config HOTPLUG
201 bool "Support for hot-pluggable devices" if !ARCH_S390
202 default ARCH_S390
203 help
204 This option is provided for the case where no in-kernel-tree
205 modules require HOTPLUG functionality, but a module built
206 outside the kernel tree does. Such modules require Y here.
207
208config KOBJECT_UEVENT
209 bool "Kernel Userspace Events" if EMBEDDED
210 depends on NET
211 default y
212 help
213 This option enables the kernel userspace event layer, which is a
214 simple mechanism for kernel-to-user communication over a netlink
215 socket.
216 The goal of the kernel userspace events layer is to provide a simple
217 and efficient events system, that notifies userspace about kobject
218 state changes. This will enable applications to just listen for
219 events instead of polling system devices and files.
220 Hotplug events (kobject addition and removal) are also available on
221 the netlink socket in addition to the execution of /sbin/hotplug if
222 CONFIG_HOTPLUG is enabled.
223
224 Say Y, unless you are building a system requiring minimal memory
225 consumption.
226
227config IKCONFIG
228 bool "Kernel .config support"
229 ---help---
230 This option enables the complete Linux kernel ".config" file
231 contents to be saved in the kernel. It provides documentation
232 of which kernel options are used in a running kernel or in an
233 on-disk kernel. This information can be extracted from the kernel
234 image file with the script scripts/extract-ikconfig and used as
235 input to rebuild the current kernel or to build another kernel.
236 It can also be extracted from a running kernel by reading
237 /proc/config.gz if enabled (below).
238
239config IKCONFIG_PROC
240 bool "Enable access to .config through /proc/config.gz"
241 depends on IKCONFIG && PROC_FS
242 ---help---
243 This option enables access to the kernel configuration file
244 through /proc/config.gz.
245
246config CPUSETS
247 bool "Cpuset support"
248 depends on SMP
249 help
250 This option will let you create and manage CPUSETs which
251 allow dynamically partitioning a system into sets of CPUs and
252 Memory Nodes and assigning tasks to run only within those sets.
253 This is primarily useful on large SMP or NUMA systems.
254
255 Say N if unsure.
256
257source "usr/Kconfig"
258
259config CC_OPTIMIZE_FOR_SIZE
260 bool "Optimize for size (Look out for broken compilers!)"
261 default y
262 depends on ARM || H8300 || EXPERIMENTAL
263 help
264 Enabling this option will pass "-Os" instead of "-O2" to gcc
265 resulting in a smaller kernel.
266
267 WARNING: some versions of gcc may generate incorrect code with this
268 option. If problems are observed, a gcc upgrade may be needed.
269
270 If unsure, say N.
271
272menuconfig EMBEDDED
273 bool "Configure standard kernel features (for small systems)"
274 help
275 This option allows certain base kernel options and settings
276 to be disabled or tweaked. This is for specialized
277 environments which can tolerate a "non-standard" kernel.
278 Only use this if you really know what you are doing.
279
280config KALLSYMS
281 bool "Load all symbols for debugging/kksymoops" if EMBEDDED
282 default y
283 help
284 Say Y here to let the kernel print out symbolic crash information and
285 symbolic stack backtraces. This increases the size of the kernel
286 somewhat, as all symbols have to be loaded into the kernel image.
287
288config KALLSYMS_ALL
289 bool "Include all symbols in kallsyms"
290 depends on DEBUG_KERNEL && KALLSYMS
291 help
292 Normally kallsyms only contains the symbols of functions, for nicer
293 OOPS messages. Some debuggers can use kallsyms for other
294 symbols too: say Y here to include all symbols, if you need them
295 and you don't care about adding 300k to the size of your kernel.
296
297 Say N.
298
299config KALLSYMS_EXTRA_PASS
300 bool "Do an extra kallsyms pass"
301 depends on KALLSYMS
302 help
303 If kallsyms is not working correctly, the build will fail with
304 inconsistent kallsyms data. If that occurs, log a bug report and
305 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
306 Always say N here unless you find a bug in kallsyms, which must be
307 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
308 you wait for kallsyms to be fixed.
309
310
311config PRINTK
312 default y
313 bool "Enable support for printk" if EMBEDDED
314 help
315 This option enables normal printk support. Removing it
316 eliminates most of the message strings from the kernel image
317 and makes the kernel more or less silent. As this makes it
318 very difficult to diagnose system problems, saying N here is
319 strongly discouraged.
320
321config BUG
322 bool "BUG() support" if EMBEDDED
323 default y
324 help
325 Disabling this option eliminates support for BUG and WARN, reducing
326 the size of your kernel image and potentially quietly ignoring
327 numerous fatal conditions. You should only consider disabling this
328 option for embedded systems with no facilities for reporting errors.
329 Just say Y.
330
331config BASE_FULL
332 default y
333 bool "Enable full-sized data structures for core" if EMBEDDED
334 help
335 Disabling this option reduces the size of miscellaneous core
336 kernel data structures. This saves memory on small machines,
337 but may reduce performance.
338
339config FUTEX
340 bool "Enable futex support" if EMBEDDED
341 default y
342 help
343 Disabling this option will cause the kernel to be built without
344 support for "fast userspace mutexes". The resulting kernel may not
345 run glibc-based applications correctly.
346
347config EPOLL
348 bool "Enable eventpoll support" if EMBEDDED
349 default y
350 help
351 Disabling this option will cause the kernel to be built without
352 support for epoll family of system calls.
353
354config SHMEM
355 bool "Use full shmem filesystem" if EMBEDDED
356 default y
357 depends on MMU
358 help
359 The shmem is an internal filesystem used to manage shared memory.
360 It is backed by swap and manages resource limits. It is also exported
361 to userspace as tmpfs if TMPFS is enabled. Disabling this
362 option replaces shmem and tmpfs with the much simpler ramfs code,
363 which may be appropriate on small systems without swap.
364
365config CC_ALIGN_FUNCTIONS
366 int "Function alignment" if EMBEDDED
367 default 0
368 help
369 Align the start of functions to the next power-of-two greater than n,
370 skipping up to n bytes. For instance, 32 aligns functions
371 to the next 32-byte boundary, but 24 would align to the next
372 32-byte boundary only if this can be done by skipping 23 bytes or less.
373 Zero means use compiler's default.
374
375config CC_ALIGN_LABELS
376 int "Label alignment" if EMBEDDED
377 default 0
378 help
379 Align all branch targets to a power-of-two boundary, skipping
380 up to n bytes like ALIGN_FUNCTIONS. This option can easily
381 make code slower, because it must insert dummy operations for
382 when the branch target is reached in the usual flow of the code.
383 Zero means use compiler's default.
384
385config CC_ALIGN_LOOPS
386 int "Loop alignment" if EMBEDDED
387 default 0
388 help
389 Align loops to a power-of-two boundary, skipping up to n bytes.
390 Zero means use compiler's default.
391
392config CC_ALIGN_JUMPS
393 int "Jump alignment" if EMBEDDED
394 default 0
395 help
396 Align branch targets to a power-of-two boundary, for branch
397 targets where the targets can only be reached by jumping,
398 skipping up to n bytes like ALIGN_FUNCTIONS. In this case,
399 no dummy operations need be executed.
400 Zero means use compiler's default.
401
402endmenu # General setup
403
404config TINY_SHMEM
405 default !SHMEM
406 bool
407
408config BASE_SMALL
409 int
410 default 0 if BASE_FULL
411 default 1 if !BASE_FULL
412
413menu "Loadable module support"
414
415config MODULES
416 bool "Enable loadable module support"
417 help
418 Kernel modules are small pieces of compiled code which can
419 be inserted in the running kernel, rather than being
420 permanently built into the kernel. You use the "modprobe"
421 tool to add (and sometimes remove) them. If you say Y here,
422 many parts of the kernel can be built as modules (by
423 answering M instead of Y where indicated): this is most
424 useful for infrequently used options which are not required
425 for booting. For more information, see the man pages for
426 modprobe, lsmod, modinfo, insmod and rmmod.
427
428 If you say Y here, you will need to run "make
429 modules_install" to put the modules under /lib/modules/
430 where modprobe can find them (you may need to be root to do
431 this).
432
433 If unsure, say Y.
434
435config MODULE_UNLOAD
436 bool "Module unloading"
437 depends on MODULES
438 help
439 Without this option you will not be able to unload any
440 modules (note that some modules may not be unloadable
441 anyway), which makes your kernel slightly smaller and
442 simpler. If unsure, say Y.
443
444config MODULE_FORCE_UNLOAD
445 bool "Forced module unloading"
446 depends on MODULE_UNLOAD && EXPERIMENTAL
447 help
448 This option allows you to force a module to unload, even if the
449 kernel believes it is unsafe: the kernel will remove the module
450 without waiting for anyone to stop using it (using the -f option to
451 rmmod). This is mainly for kernel developers and desperate users.
452 If unsure, say N.
453
454config OBSOLETE_MODPARM
455 bool
456 default y
457 depends on MODULES
458 help
459 You need this option to use module parameters on modules which
460 have not been converted to the new module parameter system yet.
461 If unsure, say Y.
462
463config MODVERSIONS
464 bool "Module versioning support (EXPERIMENTAL)"
465 depends on MODULES && EXPERIMENTAL
466 help
467 Usually, you have to use modules compiled with your kernel.
468 Saying Y here makes it sometimes possible to use modules
469 compiled for different kernels, by adding enough information
470 to the modules to (hopefully) spot any changes which would
471 make them incompatible with the kernel you are running. If
472 unsure, say N.
473
474config MODULE_SRCVERSION_ALL
475 bool "Source checksum for all modules"
476 depends on MODULES
477 help
478 Modules which contain a MODULE_VERSION get an extra "srcversion"
479 field inserted into their modinfo section, which contains a
480 sum of the source files which made it. This helps maintainers
481 see exactly which source was used to build a module (since
482 others sometimes change the module source without updating
483 the version). With this option, such a "srcversion" field
484 will be created for all modules. If unsure, say N.
485
486config KMOD
487 bool "Automatic kernel module loading"
488 depends on MODULES
489 help
490 Normally when you have selected some parts of the kernel to
491 be created as kernel modules, you must load them (using the
492 "modprobe" command) before you can use them. If you say Y
493 here, some parts of the kernel will be able to load modules
494 automatically: when a part of the kernel needs a module, it
495 runs modprobe with the appropriate arguments, thereby
496 loading the module if it is available. If unsure, say Y.
497
498config STOP_MACHINE
499 bool
500 default y
501 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
502 help
503 Need stop_machine() primitive.
504endmenu
505
506menu "Block layer"
507source "block/Kconfig"
508endmenu