2 menu "Code maturity level options"
5 bool "Prompt for development and/or incomplete code/drivers"
7 Some of the various things that Linux supports (such as network
8 drivers, file systems, network protocols, etc.) can be in a state
9 of development where the functionality, stability, or the level of
10 testing is not yet high enough for general use. This is usually
11 known as the "alpha-test" phase among developers. If a feature is
12 currently in alpha-test, then the developers usually discourage
13 uninformed widespread use of this feature by the general public to
14 avoid "Why doesn't this work?" type mail messages. However, active
15 testing and use of these systems is welcomed. Just be aware that it
16 may not meet the normal level of reliability or it may fail to work
17 in some special cases. Detailed bug reports from people familiar
18 with the kernel internals are usually welcomed by the developers
19 (before submitting bug reports, please read the documents
20 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
21 <file:Documentation/BUG-HUNTING>, and
22 <file:Documentation/oops-tracing.txt> in the kernel source).
24 This option will also make obsoleted drivers available. These are
25 drivers that have been replaced by something else, and/or are
26 scheduled to be removed in a future kernel release.
28 Unless you intend to help test and develop a feature or driver that
29 falls into this category, or you have a situation that requires
30 using these features, you should probably say N here, which will
31 cause the configurator to present you with fewer choices. If
32 you say Y here, you will be offered the choice of using features or
33 drivers that are currently considered to be in the alpha-test phase.
36 bool "Select only drivers expected to compile cleanly" if EXPERIMENTAL
39 Select this option if you don't even want to see the option
40 to configure known-broken drivers.
45 bool "Select only drivers that don't need compile-time external firmware" if EXPERIMENTAL
48 Select this option if you don't have magic firmware for drivers that
55 depends on !CLEAN_COMPILE
60 depends on BROKEN || !SMP
69 bool "Support for paging of anonymous memory"
73 This option allows you to choose whether you want to have support
74 for socalled swap devices or swap files in your kernel that are
75 used to provide more virtual memory than the actual RAM present
76 in your computer. If unsure say Y.
81 Inter Process Communication is a suite of library functions and
82 system calls which let processes (running programs) synchronize and
83 exchange information. It is generally considered to be a good thing,
84 and some programs won't run unless you say Y here. In particular, if
85 you want to run the DOS emulator dosemu under Linux (read the
86 DOSEMU-HOWTO, available from
87 <http://www.tldp.org/docs.html#howto>), you'll need to say Y
90 You can find documentation about IPC with "info ipc" and also in
91 section 6.4 of the Linux Programmer's Guide, available from
92 <http://www.tldp.org/docs.html#guide>.
94 config BSD_PROCESS_ACCT
95 bool "BSD Process Accounting"
97 If you say Y here, a user level program will be able to instruct the
98 kernel (via a special system call) to write process accounting
99 information to a file: whenever a process exits, information about
100 that process will be appended to the file by the kernel. The
101 information includes things such as creation time, owning user,
102 command name, memory usage, controlling terminal etc. (the complete
103 list is in the struct acct in <file:include/linux/acct.h>). It is
104 up to the user level program to do useful things with this
105 information. This is generally a good idea, so say Y.
108 bool "Sysctl support"
110 The sysctl interface provides a means of dynamically changing
111 certain kernel parameters and variables on the fly without requiring
112 a recompile of the kernel or reboot of the system. The primary
113 interface consists of a system call, but if you say Y to "/proc
114 file system support", a tree of modifiable sysctl entries will be
115 generated beneath the /proc/sys directory. They are explained in the
116 files in <file:Documentation/sysctl/>. Note that enabling this
117 option will enlarge the kernel by at least 8 KB.
119 As it is generally a good thing, you should say Y here unless
120 building a kernel for install/rescue disks or your system is very
124 int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" if DEBUG_KERNEL
126 default 17 if ARCH_S390
127 default 16 if X86_NUMAQ || IA64
131 Select kernel log buffer size as a power of 2.
132 Defaults and Examples:
133 17 => 128 KB for S/390
134 16 => 64 KB for x86 NUMAQ or IA-64
136 14 => 16 KB for uniprocessor
141 bool "Kernel .config support"
143 This option enables the complete Linux kernel ".config" file
144 contents, information on compiler used to build the kernel,
145 kernel running when this kernel was built and kernel version
146 from Makefile to be saved in the kernel. It provides documentation
147 of which kernel options are used in a running kernel or in an
148 on-disk kernel. This information can be extracted from the kernel
149 image file with the script scripts/extract-ikconfig and used as
150 input to rebuild the current kernel or to build another kernel.
151 It can also be extracted from a running kernel by reading
152 /proc/config.gz and /proc/config_built_with, if enabled (below).
153 /proc/config.gz will list the configuration that was used
154 to build the kernel and /proc/config_built_with will list
155 information on the compiler and host machine that was used to
159 bool "Enable access to .config through /proc/config.gz"
160 depends on IKCONFIG && PROC_FS
162 This option enables access to kernel configuration file and build
163 information through /proc/config.gz.
167 bool "Remove kernel features (for embedded systems)"
169 This option allows certain base kernel features to be removed from
170 the build. This is for specialized environments which can tolerate
171 a "non-standard" kernel. Only use this if you really know what you
175 bool "Load all symbols for debugging/kksymoops" if EMBEDDED
178 Say Y here to let the kernel print out symbolic crash information and
179 symbolic stack backtraces. This increases the size of the kernel
180 somewhat, as all symbols have to be loaded into the kernel image.
183 bool "Enable futex support" if EMBEDDED
186 Disabling this option will cause the kernel to be built without
187 support for "fast userspace mutexes". The resulting kernel may not
188 run glibc-based applications correctly.
191 bool "Enable eventpoll support" if EMBEDDED
194 Disabling this option will cause the kernel to be built without
195 support for epoll family of system calls.
197 source "drivers/block/Kconfig.iosched"
199 endmenu # General setup
202 menu "Loadable module support"
205 bool "Enable loadable module support"
207 Kernel modules are small pieces of compiled code which can
208 be inserted in the running kernel, rather than being
209 permanently built into the kernel. You use the "modprobe"
210 tool to add (and sometimes remove) them. If you say Y here,
211 many parts of the kernel can be built as modules (by
212 answering M instead of Y where indicated): this is most
213 useful for infrequently used options which are not required
214 for booting. For more information, see the man pages for
215 modprobe, lsmod, modinfo, insmod and rmmod.
217 If you say Y here, you will need to run "make
218 modules_install" to put the modules under /lib/modules/
219 where modprobe can find them (you may need to be root to do
225 bool "Module unloading"
228 Without this option you will not be able to unload any
229 modules (note that some modules may not be unloadable
230 anyway), which makes your kernel slightly smaller and
231 simpler. If unsure, say Y.
233 config MODULE_FORCE_UNLOAD
234 bool "Forced module unloading"
235 depends on MODULE_UNLOAD && EXPERIMENTAL
237 This option allows you to force a module to unload, even if the
238 kernel believes it is unsafe: the kernel will remove the module
239 without waiting for anyone to stop using it (using the -f option to
240 rmmod). This is mainly for kernel developers and desperate users.
243 config OBSOLETE_MODPARM
248 You need this option to use module parameters on modules which
249 have not been converted to the new module parameter system yet.
253 bool "Module versioning support (EXPERIMENTAL)"
254 depends on MODULES && EXPERIMENTAL
256 Usually, you have to use modules compiled with your kernel.
257 Saying Y here makes it sometimes possible to use modules
258 compiled for different kernels, by adding enough information
259 to the modules to (hopefully) spot any changes which would
260 make them incompatible with the kernel you are running. If
264 bool "Automatic kernel module loading"
267 Normally when you have selected some parts of the kernel to
268 be created as kernel modules, you must load them (using the
269 "modprobe" command) before you can use them. If you say Y
270 here, some parts of the kernel will be able to load modules
271 automatically: when a part of the kernel needs a module, it
272 runs modprobe with the appropriate arguments, thereby
273 loading the module if it is available. If unsure, say Y.