4 default "/lib/modules/$UNAME_RELEASE/.config"
5 default "/etc/kernel-config"
6 default "/boot/config-$UNAME_RELEASE"
7 default "arch/$ARCH/defconfig"
9 menu "Code maturity level options"
12 bool "Prompt for development and/or incomplete code/drivers"
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).
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32 drivers that have been replaced by something else, and/or are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.
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.
47 depends on BROKEN || !SMP
52 depends on SMP || PREEMPT
55 config INIT_ENV_ARG_LIMIT
60 Maximum of each of the number of arguments and environment
61 variables passed to init from the kernel command line.
68 string "Local version - append to kernel release"
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.
77 config LOCALVERSION_AUTO
78 bool "Automatically append version information to the version string"
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.
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
90 Note: This requires Perl, and a git repository, but not necessarily
91 the git or cogito tools to be installed.
94 bool "Support for paging of anonymous memory (swap)"
98 This option allows you to choose whether you want to have support
99 for so called swap devices or swap files in your kernel that are
100 used to provide more virtual memory than the actual RAM present
101 in your computer. If unsure say Y.
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.
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>.
119 bool "POSIX Message Queues"
120 depends on NET && EXPERIMENTAL
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/>
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.
136 config BSD_PROCESS_ACCT
137 bool "BSD Process Accounting"
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.
149 config BSD_PROCESS_ACCT_V3
150 bool "BSD Process Accounting version 3 file format"
151 depends on BSD_PROCESS_ACCT
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/>.
161 config TASK_DELAY_ACCT
162 bool "Enable per-task delay accounting (EXPERIMENTAL)"
164 Collect information on time spent by a task waiting for system
165 resources like cpu, synchronous block I/O completion and swapping
166 in pages. Such statistics can help in setting a task's priorities
167 relative to other tasks for cpu, io, rss limits etc.
172 bool "Sysctl support" if EMBEDDED
175 The sysctl interface provides a means of dynamically changing
176 certain kernel parameters and variables on the fly without requiring
177 a recompile of the kernel or reboot of the system. The primary
178 interface consists of a system call, but if you say Y to "/proc
179 file system support", a tree of modifiable sysctl entries will be
180 generated beneath the /proc/sys directory. They are explained in the
181 files in <file:Documentation/sysctl/>. Note that enabling this
182 option will enlarge the kernel by at least 8 KB.
184 As it is generally a good thing, you should say Y here unless
185 building a kernel for install/rescue disks or your system is very
189 bool "Auditing support"
192 Enable auditing infrastructure that can be used with another
193 kernel subsystem, such as SELinux (which requires this for
194 logging of avc messages output). Does not do system-call
195 auditing without CONFIG_AUDITSYSCALL.
198 bool "Enable system-call auditing support"
199 depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64)
200 default y if SECURITY_SELINUX
202 Enable low-overhead system-call auditing infrastructure that
203 can be used independently or with another kernel subsystem,
204 such as SELinux. To use audit's filesystem watch feature, please
205 ensure that INOTIFY is configured.
208 bool "Kernel .config support"
210 This option enables the complete Linux kernel ".config" file
211 contents to be saved in the kernel. It provides documentation
212 of which kernel options are used in a running kernel or in an
213 on-disk kernel. This information can be extracted from the kernel
214 image file with the script scripts/extract-ikconfig and used as
215 input to rebuild the current kernel or to build another kernel.
216 It can also be extracted from a running kernel by reading
217 /proc/config.gz if enabled (below).
220 bool "Enable access to .config through /proc/config.gz"
221 depends on IKCONFIG && PROC_FS
223 This option enables access to the kernel configuration file
224 through /proc/config.gz.
227 bool "Cpuset support"
230 This option will let you create and manage CPUSETs which
231 allow dynamically partitioning a system into sets of CPUs and
232 Memory Nodes and assigning tasks to run only within those sets.
233 This is primarily useful on large SMP or NUMA systems.
238 bool "Kernel->user space relay support (formerly relayfs)"
240 This option enables support for relay interface support in
241 certain file systems (such as debugfs).
242 It is designed to provide an efficient mechanism for tools and
243 facilities to relay large amounts of data from kernel space to
251 bool "Enable 16-bit UID system calls" if EMBEDDED
252 depends on ARM || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION)
255 This enables the legacy 16-bit UID syscall wrappers.
257 config CC_OPTIMIZE_FOR_SIZE
258 bool "Optimize for size (Look out for broken compilers!)"
260 depends on ARM || H8300 || EXPERIMENTAL
262 Enabling this option will pass "-Os" instead of "-O2" to gcc
263 resulting in a smaller kernel.
265 WARNING: some versions of gcc may generate incorrect code with this
266 option. If problems are observed, a gcc upgrade may be needed.
271 bool "Configure standard kernel features (for small systems)"
273 This option allows certain base kernel options and settings
274 to be disabled or tweaked. This is for specialized
275 environments which can tolerate a "non-standard" kernel.
276 Only use this if you really know what you are doing.
279 bool "Load all symbols for debugging/kksymoops" if EMBEDDED
282 Say Y here to let the kernel print out symbolic crash information and
283 symbolic stack backtraces. This increases the size of the kernel
284 somewhat, as all symbols have to be loaded into the kernel image.
287 bool "Include all symbols in kallsyms"
288 depends on DEBUG_KERNEL && KALLSYMS
290 Normally kallsyms only contains the symbols of functions, for nicer
291 OOPS messages. Some debuggers can use kallsyms for other
292 symbols too: say Y here to include all symbols, if you need them
293 and you don't care about adding 300k to the size of your kernel.
297 config KALLSYMS_EXTRA_PASS
298 bool "Do an extra kallsyms pass"
301 If kallsyms is not working correctly, the build will fail with
302 inconsistent kallsyms data. If that occurs, log a bug report and
303 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
304 Always say N here unless you find a bug in kallsyms, which must be
305 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
306 you wait for kallsyms to be fixed.
310 bool "Support for hot-pluggable devices" if EMBEDDED
313 This option is provided for the case where no hotplug or uevent
314 capabilities is wanted by the kernel. You should only consider
315 disabling this option for embedded systems that do not use modules, a
316 dynamic /dev tree, or dynamic device discovery. Just say Y.
320 bool "Enable support for printk" if EMBEDDED
322 This option enables normal printk support. Removing it
323 eliminates most of the message strings from the kernel image
324 and makes the kernel more or less silent. As this makes it
325 very difficult to diagnose system problems, saying N here is
326 strongly discouraged.
329 bool "BUG() support" if EMBEDDED
332 Disabling this option eliminates support for BUG and WARN, reducing
333 the size of your kernel image and potentially quietly ignoring
334 numerous fatal conditions. You should only consider disabling this
335 option for embedded systems with no facilities for reporting errors.
340 bool "Enable ELF core dumps" if EMBEDDED
342 Enable support for generating core dumps. Disabling saves about 4k.
346 bool "Enable full-sized data structures for core" if EMBEDDED
348 Disabling this option reduces the size of miscellaneous core
349 kernel data structures. This saves memory on small machines,
350 but may reduce performance.
357 bool "Enable futex support" if EMBEDDED
361 Disabling this option will cause the kernel to be built without
362 support for "fast userspace mutexes". The resulting kernel may not
363 run glibc-based applications correctly.
366 bool "Enable eventpoll support" if EMBEDDED
369 Disabling this option will cause the kernel to be built without
370 support for epoll family of system calls.
373 bool "Use full shmem filesystem" if EMBEDDED
377 The shmem is an internal filesystem used to manage shared memory.
378 It is backed by swap and manages resource limits. It is also exported
379 to userspace as tmpfs if TMPFS is enabled. Disabling this
380 option replaces shmem and tmpfs with the much simpler ramfs code,
381 which may be appropriate on small systems without swap.
385 bool "Use full SLAB allocator" if EMBEDDED
387 Disabling this replaces the advanced SLAB allocator and
388 kmalloc support with the drastically simpler SLOB allocator.
389 SLOB is more space efficient but does not scale well and is
390 more susceptible to fragmentation.
392 config VM_EVENT_COUNTERS
394 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
396 VM event counters are only needed to for event counts to be
397 shown. They have no function for the kernel itself. This
398 option allows the disabling of the VM event counters.
399 /proc/vmstat will only show page counts.
401 endmenu # General setup
409 default 0 if BASE_FULL
410 default 1 if !BASE_FULL
416 menu "Loadable module support"
419 bool "Enable loadable module support"
421 Kernel modules are small pieces of compiled code which can
422 be inserted in the running kernel, rather than being
423 permanently built into the kernel. You use the "modprobe"
424 tool to add (and sometimes remove) them. If you say Y here,
425 many parts of the kernel can be built as modules (by
426 answering M instead of Y where indicated): this is most
427 useful for infrequently used options which are not required
428 for booting. For more information, see the man pages for
429 modprobe, lsmod, modinfo, insmod and rmmod.
431 If you say Y here, you will need to run "make
432 modules_install" to put the modules under /lib/modules/
433 where modprobe can find them (you may need to be root to do
439 bool "Module unloading"
442 Without this option you will not be able to unload any
443 modules (note that some modules may not be unloadable
444 anyway), which makes your kernel slightly smaller and
445 simpler. If unsure, say Y.
447 config MODULE_FORCE_UNLOAD
448 bool "Forced module unloading"
449 depends on MODULE_UNLOAD && EXPERIMENTAL
451 This option allows you to force a module to unload, even if the
452 kernel believes it is unsafe: the kernel will remove the module
453 without waiting for anyone to stop using it (using the -f option to
454 rmmod). This is mainly for kernel developers and desperate users.
458 bool "Module versioning support"
461 Usually, you have to use modules compiled with your kernel.
462 Saying Y here makes it sometimes possible to use modules
463 compiled for different kernels, by adding enough information
464 to the modules to (hopefully) spot any changes which would
465 make them incompatible with the kernel you are running. If
468 config MODULE_SRCVERSION_ALL
469 bool "Source checksum for all modules"
472 Modules which contain a MODULE_VERSION get an extra "srcversion"
473 field inserted into their modinfo section, which contains a
474 sum of the source files which made it. This helps maintainers
475 see exactly which source was used to build a module (since
476 others sometimes change the module source without updating
477 the version). With this option, such a "srcversion" field
478 will be created for all modules. If unsure, say N.
481 bool "Automatic kernel module loading"
484 Normally when you have selected some parts of the kernel to
485 be created as kernel modules, you must load them (using the
486 "modprobe" command) before you can use them. If you say Y
487 here, some parts of the kernel will be able to load modules
488 automatically: when a part of the kernel needs a module, it
489 runs modprobe with the appropriate arguments, thereby
490 loading the module if it is available. If unsure, say Y.
495 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
497 Need stop_machine() primitive.
501 source "block/Kconfig"