1 menu "Code maturity level options"
4 bool "Prompt for development and/or incomplete code/drivers"
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).
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24 drivers that have been replaced by something else, and/or are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.
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.
35 bool "Select only drivers expected to compile cleanly" if EXPERIMENTAL
38 Select this option if you don't even want to see the option
39 to configure known-broken drivers.
45 depends on !CLEAN_COMPILE
50 depends on BROKEN || !SMP
55 depends on SMP || PREEMPT
58 config INIT_ENV_ARG_LIMIT
60 default 32 if !USERMODE
61 default 128 if USERMODE
63 Maximum of each of the number of arguments and environment
64 variables passed to init from the kernel command line.
71 string "Local version - append to kernel release"
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.
80 config LOCALVERSION_AUTO
81 bool "Automatically append version information to the version string"
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.
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
93 Note: This requires Perl, and a git repository, but not necessarily
94 the git or cogito tools to be installed.
97 bool "Support for paging of anonymous memory (swap)"
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.
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.
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>.
123 bool "POSIX Message Queues"
124 depends on NET && EXPERIMENTAL
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/>
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.
140 config BSD_PROCESS_ACCT
141 bool "BSD Process Accounting"
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.
153 config BSD_PROCESS_ACCT_V3
154 bool "BSD Process Accounting version 3 file format"
155 depends on BSD_PROCESS_ACCT
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/>.
166 bool "Sysctl support"
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.
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
182 bool "Auditing support"
184 default y if SECURITY_SELINUX
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.
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
196 Enable low-overhead system-call auditing infrastructure that
197 can be used independently or with another kernel subsystem,
201 bool "Support for hot-pluggable devices" if !ARCH_S390
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.
208 config KOBJECT_UEVENT
209 bool "Kernel Userspace Events" if EMBEDDED
213 This option enables the kernel userspace event layer, which is a
214 simple mechanism for kernel-to-user communication over a netlink
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.
224 Say Y, unless you are building a system requiring minimal memory
228 bool "Kernel .config support"
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).
240 bool "Enable access to .config through /proc/config.gz"
241 depends on IKCONFIG && PROC_FS
243 This option enables access to the kernel configuration file
244 through /proc/config.gz.
247 bool "Cpuset support"
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.
259 config CC_OPTIMIZE_FOR_SIZE
260 bool "Optimize for size (Look out for broken compilers!)"
262 depends on ARM || H8300 || EXPERIMENTAL
265 Enabling this option will pass "-Os" instead of "-O2" to gcc
266 resulting in a smaller kernel.
268 WARNING: some versions of gcc may generate incorrect code with this
269 option. If problems are observed, a gcc upgrade may be needed.
274 bool "Configure standard kernel features (for small systems)"
276 This option allows certain base kernel options and settings
277 to be disabled or tweaked. This is for specialized
278 environments which can tolerate a "non-standard" kernel.
279 Only use this if you really know what you are doing.
282 bool "Load all symbols for debugging/kksymoops" if EMBEDDED
285 Say Y here to let the kernel print out symbolic crash information and
286 symbolic stack backtraces. This increases the size of the kernel
287 somewhat, as all symbols have to be loaded into the kernel image.
290 bool "Include all symbols in kallsyms"
291 depends on DEBUG_KERNEL && KALLSYMS
293 Normally kallsyms only contains the symbols of functions, for nicer
294 OOPS messages. Some debuggers can use kallsyms for other
295 symbols too: say Y here to include all symbols, if you need them
296 and you don't care about adding 300k to the size of your kernel.
300 config KALLSYMS_EXTRA_PASS
301 bool "Do an extra kallsyms pass"
304 If kallsyms is not working correctly, the build will fail with
305 inconsistent kallsyms data. If that occurs, log a bug report and
306 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
307 Always say N here unless you find a bug in kallsyms, which must be
308 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
309 you wait for kallsyms to be fixed.
314 bool "Enable support for printk" if EMBEDDED
316 This option enables normal printk support. Removing it
317 eliminates most of the message strings from the kernel image
318 and makes the kernel more or less silent. As this makes it
319 very difficult to diagnose system problems, saying N here is
320 strongly discouraged.
323 bool "BUG() support" if EMBEDDED
326 Disabling this option eliminates support for BUG and WARN, reducing
327 the size of your kernel image and potentially quietly ignoring
328 numerous fatal conditions. You should only consider disabling this
329 option for embedded systems with no facilities for reporting errors.
334 bool "Enable full-sized data structures for core" if EMBEDDED
336 Disabling this option reduces the size of miscellaneous core
337 kernel data structures. This saves memory on small machines,
338 but may reduce performance.
341 bool "Enable futex support" if EMBEDDED
344 Disabling this option will cause the kernel to be built without
345 support for "fast userspace mutexes". The resulting kernel may not
346 run glibc-based applications correctly.
349 bool "Enable eventpoll support" if EMBEDDED
352 Disabling this option will cause the kernel to be built without
353 support for epoll family of system calls.
356 bool "Use full shmem filesystem" if EMBEDDED
360 The shmem is an internal filesystem used to manage shared memory.
361 It is backed by swap and manages resource limits. It is also exported
362 to userspace as tmpfs if TMPFS is enabled. Disabling this
363 option replaces shmem and tmpfs with the much simpler ramfs code,
364 which may be appropriate on small systems without swap.
366 config CC_ALIGN_FUNCTIONS
367 int "Function alignment" if EMBEDDED
370 Align the start of functions to the next power-of-two greater than n,
371 skipping up to n bytes. For instance, 32 aligns functions
372 to the next 32-byte boundary, but 24 would align to the next
373 32-byte boundary only if this can be done by skipping 23 bytes or less.
374 Zero means use compiler's default.
376 config CC_ALIGN_LABELS
377 int "Label alignment" if EMBEDDED
380 Align all branch targets to a power-of-two boundary, skipping
381 up to n bytes like ALIGN_FUNCTIONS. This option can easily
382 make code slower, because it must insert dummy operations for
383 when the branch target is reached in the usual flow of the code.
384 Zero means use compiler's default.
386 config CC_ALIGN_LOOPS
387 int "Loop alignment" if EMBEDDED
390 Align loops to a power-of-two boundary, skipping up to n bytes.
391 Zero means use compiler's default.
393 config CC_ALIGN_JUMPS
394 int "Jump alignment" if EMBEDDED
397 Align branch targets to a power-of-two boundary, for branch
398 targets where the targets can only be reached by jumping,
399 skipping up to n bytes like ALIGN_FUNCTIONS. In this case,
400 no dummy operations need be executed.
401 Zero means use compiler's default.
403 endmenu # General setup
411 default 0 if BASE_FULL
412 default 1 if !BASE_FULL
414 menu "Loadable module support"
417 bool "Enable loadable module support"
419 Kernel modules are small pieces of compiled code which can
420 be inserted in the running kernel, rather than being
421 permanently built into the kernel. You use the "modprobe"
422 tool to add (and sometimes remove) them. If you say Y here,
423 many parts of the kernel can be built as modules (by
424 answering M instead of Y where indicated): this is most
425 useful for infrequently used options which are not required
426 for booting. For more information, see the man pages for
427 modprobe, lsmod, modinfo, insmod and rmmod.
429 If you say Y here, you will need to run "make
430 modules_install" to put the modules under /lib/modules/
431 where modprobe can find them (you may need to be root to do
437 bool "Module unloading"
440 Without this option you will not be able to unload any
441 modules (note that some modules may not be unloadable
442 anyway), which makes your kernel slightly smaller and
443 simpler. If unsure, say Y.
445 config MODULE_FORCE_UNLOAD
446 bool "Forced module unloading"
447 depends on MODULE_UNLOAD && EXPERIMENTAL
449 This option allows you to force a module to unload, even if the
450 kernel believes it is unsafe: the kernel will remove the module
451 without waiting for anyone to stop using it (using the -f option to
452 rmmod). This is mainly for kernel developers and desperate users.
455 config OBSOLETE_MODPARM
460 You need this option to use module parameters on modules which
461 have not been converted to the new module parameter system yet.
465 bool "Module versioning support (EXPERIMENTAL)"
466 depends on MODULES && EXPERIMENTAL
468 Usually, you have to use modules compiled with your kernel.
469 Saying Y here makes it sometimes possible to use modules
470 compiled for different kernels, by adding enough information
471 to the modules to (hopefully) spot any changes which would
472 make them incompatible with the kernel you are running. If
475 config MODULE_SRCVERSION_ALL
476 bool "Source checksum for all modules"
479 Modules which contain a MODULE_VERSION get an extra "srcversion"
480 field inserted into their modinfo section, which contains a
481 sum of the source files which made it. This helps maintainers
482 see exactly which source was used to build a module (since
483 others sometimes change the module source without updating
484 the version). With this option, such a "srcversion" field
485 will be created for all modules. If unsure, say N.
488 bool "Automatic kernel module loading"
491 Normally when you have selected some parts of the kernel to
492 be created as kernel modules, you must load them (using the
493 "modprobe" command) before you can use them. If you say Y
494 here, some parts of the kernel will be able to load modules
495 automatically: when a part of the kernel needs a module, it
496 runs modprobe with the appropriate arguments, thereby
497 loading the module if it is available. If unsure, say Y.
502 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
504 Need stop_machine() primitive.
508 source "block/Kconfig"
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