5 default "/lib/modules/$UNAME_RELEASE/.config"
6 default "/etc/kernel-config"
7 default "/boot/config-$UNAME_RELEASE"
8 default "arch/$ARCH/defconfig"
10 menu "Code maturity level options"
13 bool "Prompt for development and/or incomplete code/drivers"
15 Some of the various things that Linux supports (such as network
16 drivers, file systems, network protocols, etc.) can be in a state
17 of development where the functionality, stability, or the level of
18 testing is not yet high enough for general use. This is usually
19 known as the "alpha-test" phase among developers. If a feature is
20 currently in alpha-test, then the developers usually discourage
21 uninformed widespread use of this feature by the general public to
22 avoid "Why doesn't this work?" type mail messages. However, active
23 testing and use of these systems is welcomed. Just be aware that it
24 may not meet the normal level of reliability or it may fail to work
25 in some special cases. Detailed bug reports from people familiar
26 with the kernel internals are usually welcomed by the developers
27 (before submitting bug reports, please read the documents
28 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
29 <file:Documentation/BUG-HUNTING>, and
30 <file:Documentation/oops-tracing.txt> in the kernel source).
32 This option will also make obsoleted drivers available. These are
33 drivers that have been replaced by something else, and/or are
34 scheduled to be removed in a future kernel release.
36 Unless you intend to help test and develop a feature or driver that
37 falls into this category, or you have a situation that requires
38 using these features, you should probably say N here, which will
39 cause the configurator to present you with fewer choices. If
40 you say Y here, you will be offered the choice of using features or
41 drivers that are currently considered to be in the alpha-test phase.
48 depends on BROKEN || !SMP
53 depends on SMP || PREEMPT
56 config INIT_ENV_ARG_LIMIT
61 Maximum of each of the number of arguments and environment
62 variables passed to init from the kernel command line.
69 string "Local version - append to kernel release"
71 Append an extra string to the end of your kernel version.
72 This will show up when you type uname, for example.
73 The string you set here will be appended after the contents of
74 any files with a filename matching localversion* in your
75 object and source tree, in that order. Your total string can
76 be a maximum of 64 characters.
78 config LOCALVERSION_AUTO
79 bool "Automatically append version information to the version string"
82 This will try to automatically determine if the current tree is a
83 release tree by looking for git tags that
84 belong to the current top of tree revision.
86 A string of the format -gxxxxxxxx will be added to the localversion
87 if a git based tree is found. The string generated by this will be
88 appended after any matching localversion* files, and after the value
89 set in CONFIG_LOCALVERSION
91 Note: This requires Perl, and a git repository, but not necessarily
92 the git or cogito tools to be installed.
95 bool "Support for paging of anonymous memory (swap)"
99 This option allows you to choose whether you want to have support
100 for so called swap devices or swap files in your kernel that are
101 used to provide more virtual memory than the actual RAM present
102 in your computer. If unsure say Y.
107 Inter Process Communication is a suite of library functions and
108 system calls which let processes (running programs) synchronize and
109 exchange information. It is generally considered to be a good thing,
110 and some programs won't run unless you say Y here. In particular, if
111 you want to run the DOS emulator dosemu under Linux (read the
112 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
113 you'll need to say Y here.
115 You can find documentation about IPC with "info ipc" and also in
116 section 6.4 of the Linux Programmer's Guide, available from
117 <http://www.tldp.org/guides.html>.
120 bool "POSIX Message Queues"
121 depends on NET && EXPERIMENTAL
123 POSIX variant of message queues is a part of IPC. In POSIX message
124 queues every message has a priority which decides about succession
125 of receiving it by a process. If you want to compile and run
126 programs written e.g. for Solaris with use of its POSIX message
127 queues (functions mq_*) say Y here. To use this feature you will
128 also need mqueue library, available from
129 <http://www.mat.uni.torun.pl/~wrona/posix_ipc/>
131 POSIX message queues are visible as a filesystem called 'mqueue'
132 and can be mounted somewhere if you want to do filesystem
133 operations on message queues.
137 config BSD_PROCESS_ACCT
138 bool "BSD Process Accounting"
140 If you say Y here, a user level program will be able to instruct the
141 kernel (via a special system call) to write process accounting
142 information to a file: whenever a process exits, information about
143 that process will be appended to the file by the kernel. The
144 information includes things such as creation time, owning user,
145 command name, memory usage, controlling terminal etc. (the complete
146 list is in the struct acct in <file:include/linux/acct.h>). It is
147 up to the user level program to do useful things with this
148 information. This is generally a good idea, so say Y.
150 config BSD_PROCESS_ACCT_V3
151 bool "BSD Process Accounting version 3 file format"
152 depends on BSD_PROCESS_ACCT
155 If you say Y here, the process accounting information is written
156 in a new file format that also logs the process IDs of each
157 process and it's parent. Note that this file format is incompatible
158 with previous v0/v1/v2 file formats, so you will need updated tools
159 for processing it. A preliminary version of these tools is available
160 at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>.
163 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
167 Export selected statistics for tasks/processes through the
168 generic netlink interface. Unlike BSD process accounting, the
169 statistics are available during the lifetime of tasks/processes as
170 responses to commands. Like BSD accounting, they are sent to user
175 config TASK_DELAY_ACCT
176 bool "Enable per-task delay accounting (EXPERIMENTAL)"
179 Collect information on time spent by a task waiting for system
180 resources like cpu, synchronous block I/O completion and swapping
181 in pages. Such statistics can help in setting a task's priorities
182 relative to other tasks for cpu, io, rss limits etc.
187 bool "Auditing support"
190 Enable auditing infrastructure that can be used with another
191 kernel subsystem, such as SELinux (which requires this for
192 logging of avc messages output). Does not do system-call
193 auditing without CONFIG_AUDITSYSCALL.
196 bool "Enable system-call auditing support"
197 depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64)
198 default y if SECURITY_SELINUX
200 Enable low-overhead system-call auditing infrastructure that
201 can be used independently or with another kernel subsystem,
202 such as SELinux. To use audit's filesystem watch feature, please
203 ensure that INOTIFY is configured.
206 bool "Kernel .config support"
208 This option enables the complete Linux kernel ".config" file
209 contents to be saved in the kernel. It provides documentation
210 of which kernel options are used in a running kernel or in an
211 on-disk kernel. This information can be extracted from the kernel
212 image file with the script scripts/extract-ikconfig and used as
213 input to rebuild the current kernel or to build another kernel.
214 It can also be extracted from a running kernel by reading
215 /proc/config.gz if enabled (below).
218 bool "Enable access to .config through /proc/config.gz"
219 depends on IKCONFIG && PROC_FS
221 This option enables access to the kernel configuration file
222 through /proc/config.gz.
228 This option enables panic() to be called when a system is out of
229 memory. This feature along with /proc/sys/kernel/panic allows a
230 different behavior on out-of-memory conditions when the standard
231 behavior (killing processes in an attempt to recover) does not
238 depends on !OOM_PANIC
242 bool "Cpuset support"
245 This option will let you create and manage CPUSETs which
246 allow dynamically partitioning a system into sets of CPUs and
247 Memory Nodes and assigning tasks to run only within those sets.
248 This is primarily useful on large SMP or NUMA systems.
253 bool "Kernel->user space relay support (formerly relayfs)"
255 This option enables support for relay interface support in
256 certain file systems (such as debugfs).
257 It is designed to provide an efficient mechanism for tools and
258 facilities to relay large amounts of data from kernel space to
265 config CC_OPTIMIZE_FOR_SIZE
266 bool "Optimize for size (Look out for broken compilers!)"
268 depends on ARM || H8300 || EXPERIMENTAL
270 Enabling this option will pass "-Os" instead of "-O2" to gcc
271 resulting in a smaller kernel.
273 WARNING: some versions of gcc may generate incorrect code with this
274 option. If problems are observed, a gcc upgrade may be needed.
279 bool "Configure standard kernel features (for small systems)"
281 This option allows certain base kernel options and settings
282 to be disabled or tweaked. This is for specialized
283 environments which can tolerate a "non-standard" kernel.
284 Only use this if you really know what you are doing.
287 bool "Enable 16-bit UID system calls" if EMBEDDED
288 depends on ARM || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION)
291 This enables the legacy 16-bit UID syscall wrappers.
294 bool "Sysctl support" if EMBEDDED
297 The sysctl interface provides a means of dynamically changing
298 certain kernel parameters and variables on the fly without requiring
299 a recompile of the kernel or reboot of the system. The primary
300 interface consists of a system call, but if you say Y to "/proc
301 file system support", a tree of modifiable sysctl entries will be
302 generated beneath the /proc/sys directory. They are explained in the
303 files in <file:Documentation/sysctl/>. Note that enabling this
304 option will enlarge the kernel by at least 8 KB.
306 As it is generally a good thing, you should say Y here unless
307 building a kernel for install/rescue disks or your system is very
311 bool "Load all symbols for debugging/kksymoops" if EMBEDDED
314 Say Y here to let the kernel print out symbolic crash information and
315 symbolic stack backtraces. This increases the size of the kernel
316 somewhat, as all symbols have to be loaded into the kernel image.
319 bool "Include all symbols in kallsyms"
320 depends on DEBUG_KERNEL && KALLSYMS
322 Normally kallsyms only contains the symbols of functions, for nicer
323 OOPS messages. Some debuggers can use kallsyms for other
324 symbols too: say Y here to include all symbols, if you need them
325 and you don't care about adding 300k to the size of your kernel.
329 config KALLSYMS_EXTRA_PASS
330 bool "Do an extra kallsyms pass"
333 If kallsyms is not working correctly, the build will fail with
334 inconsistent kallsyms data. If that occurs, log a bug report and
335 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
336 Always say N here unless you find a bug in kallsyms, which must be
337 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
338 you wait for kallsyms to be fixed.
342 bool "Support for hot-pluggable devices" if EMBEDDED
345 This option is provided for the case where no hotplug or uevent
346 capabilities is wanted by the kernel. You should only consider
347 disabling this option for embedded systems that do not use modules, a
348 dynamic /dev tree, or dynamic device discovery. Just say Y.
352 bool "Enable support for printk" if EMBEDDED
354 This option enables normal printk support. Removing it
355 eliminates most of the message strings from the kernel image
356 and makes the kernel more or less silent. As this makes it
357 very difficult to diagnose system problems, saying N here is
358 strongly discouraged.
361 bool "BUG() support" if EMBEDDED
364 Disabling this option eliminates support for BUG and WARN, reducing
365 the size of your kernel image and potentially quietly ignoring
366 numerous fatal conditions. You should only consider disabling this
367 option for embedded systems with no facilities for reporting errors.
372 bool "Enable ELF core dumps" if EMBEDDED
374 Enable support for generating core dumps. Disabling saves about 4k.
378 bool "Enable full-sized data structures for core" if EMBEDDED
380 Disabling this option reduces the size of miscellaneous core
381 kernel data structures. This saves memory on small machines,
382 but may reduce performance.
385 bool "Enable futex support" if EMBEDDED
389 Disabling this option will cause the kernel to be built without
390 support for "fast userspace mutexes". The resulting kernel may not
391 run glibc-based applications correctly.
394 bool "Enable eventpoll support" if EMBEDDED
397 Disabling this option will cause the kernel to be built without
398 support for epoll family of system calls.
401 bool "Use full shmem filesystem" if EMBEDDED
405 The shmem is an internal filesystem used to manage shared memory.
406 It is backed by swap and manages resource limits. It is also exported
407 to userspace as tmpfs if TMPFS is enabled. Disabling this
408 option replaces shmem and tmpfs with the much simpler ramfs code,
409 which may be appropriate on small systems without swap.
413 bool "Use full SLAB allocator" if EMBEDDED
415 Disabling this replaces the advanced SLAB allocator and
416 kmalloc support with the drastically simpler SLOB allocator.
417 SLOB is more space efficient but does not scale well and is
418 more susceptible to fragmentation.
420 config VM_EVENT_COUNTERS
422 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
424 VM event counters are only needed to for event counts to be
425 shown. They have no function for the kernel itself. This
426 option allows the disabling of the VM event counters.
427 /proc/vmstat will only show page counts.
429 endmenu # General setup
441 default 0 if BASE_FULL
442 default 1 if !BASE_FULL
448 menu "Loadable module support"
451 bool "Enable loadable module support"
453 Kernel modules are small pieces of compiled code which can
454 be inserted in the running kernel, rather than being
455 permanently built into the kernel. You use the "modprobe"
456 tool to add (and sometimes remove) them. If you say Y here,
457 many parts of the kernel can be built as modules (by
458 answering M instead of Y where indicated): this is most
459 useful for infrequently used options which are not required
460 for booting. For more information, see the man pages for
461 modprobe, lsmod, modinfo, insmod and rmmod.
463 If you say Y here, you will need to run "make
464 modules_install" to put the modules under /lib/modules/
465 where modprobe can find them (you may need to be root to do
471 bool "Module unloading"
474 Without this option you will not be able to unload any
475 modules (note that some modules may not be unloadable
476 anyway), which makes your kernel slightly smaller and
477 simpler. If unsure, say Y.
479 config MODULE_FORCE_UNLOAD
480 bool "Forced module unloading"
481 depends on MODULE_UNLOAD && EXPERIMENTAL
483 This option allows you to force a module to unload, even if the
484 kernel believes it is unsafe: the kernel will remove the module
485 without waiting for anyone to stop using it (using the -f option to
486 rmmod). This is mainly for kernel developers and desperate users.
490 bool "Module versioning support"
493 Usually, you have to use modules compiled with your kernel.
494 Saying Y here makes it sometimes possible to use modules
495 compiled for different kernels, by adding enough information
496 to the modules to (hopefully) spot any changes which would
497 make them incompatible with the kernel you are running. If
500 config MODULE_SRCVERSION_ALL
501 bool "Source checksum for all modules"
504 Modules which contain a MODULE_VERSION get an extra "srcversion"
505 field inserted into their modinfo section, which contains a
506 sum of the source files which made it. This helps maintainers
507 see exactly which source was used to build a module (since
508 others sometimes change the module source without updating
509 the version). With this option, such a "srcversion" field
510 will be created for all modules. If unsure, say N.
513 bool "Module signature verification (EXPERIMENTAL)"
514 depends on MODULES && EXPERIMENTAL
517 select CRYPTO_SIGNATURE
519 Check modules for valid signatures upon load.
521 config MODULE_SIG_FORCE
522 bool "Required modules to be validly signed (EXPERIMENTAL)"
523 depends on MODULE_SIG
525 Reject unsigned modules or signed modules for which we don't have a
529 bool "Automatic kernel module loading"
532 Normally when you have selected some parts of the kernel to
533 be created as kernel modules, you must load them (using the
534 "modprobe" command) before you can use them. If you say Y
535 here, some parts of the kernel will be able to load modules
536 automatically: when a part of the kernel needs a module, it
537 runs modprobe with the appropriate arguments, thereby
538 loading the module if it is available. If unsure, say Y.
543 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
545 Need stop_machine() primitive.
548 menu "Process debugging support"
551 bool "Infrastructure for tracing and debugging user processes"
554 Enable the utrace process tracing interface.
555 This is an internal kernel interface to track events in user
556 threads, extract and change user thread state. This interface
557 is exported to kernel modules, and is also used to implement ptrace.
558 If you disable this, no facilities for debugging user processes
559 will be available, nor the facilities used by UML and other
560 applications. Unless you are making a specially stripped-down
561 kernel and are very sure you don't need these facilitiies,
565 bool "Legacy ptrace system call interface"
569 Enable the ptrace system call.
570 This is traditionally used by debuggers like GDB,
571 and is used by UML and some other applications.
572 Unless you are very sure you won't run anything that needs it,
578 source "block/Kconfig"