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menu "Code maturity level options"
config EXPERIMENTAL
bool "Prompt for development and/or incomplete code/drivers"
---help---
Some of the various things that Linux supports (such as network
drivers, file systems, network protocols, etc.) can be in a state
of development where the functionality, stability, or the level of
testing is not yet high enough for general use. This is usually
known as the "alpha-test" phase among developers. If a feature is
currently in alpha-test, then the developers usually discourage
uninformed widespread use of this feature by the general public to
avoid "Why doesn't this work?" type mail messages. However, active
testing and use of these systems is welcomed. Just be aware that it
may not meet the normal level of reliability or it may fail to work
in some special cases. Detailed bug reports from people familiar
with the kernel internals are usually welcomed by the developers
(before submitting bug reports, please read the documents
<file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
<file:Documentation/BUG-HUNTING>, and
<file:Documentation/oops-tracing.txt> in the kernel source).
This option will also make obsoleted drivers available. These are
drivers that have been replaced by something else, and/or are
scheduled to be removed in a future kernel release.
Unless you intend to help test and develop a feature or driver that
falls into this category, or you have a situation that requires
using these features, you should probably say N here, which will
cause the configurator to present you with fewer choices. If
you say Y here, you will be offered the choice of using features or
drivers that are currently considered to be in the alpha-test phase.
config CLEAN_COMPILE
bool "Select only drivers expected to compile cleanly" if EXPERIMENTAL
default y
help
Select this option if you don't even want to see the option
to configure known-broken drivers.
If unsure, say Y
config STANDALONE
bool "Select only drivers that don't need compile-time external firmware" if EXPERIMENTAL
default y
help
Select this option if you don't have magic firmware for drivers that
need it.
If unsure, say Y.
config BROKEN
bool
depends on !CLEAN_COMPILE
default y
config BROKEN_ON_SMP
bool
depends on BROKEN || !SMP
default y
endmenu
menu "General setup"
config SWAP
bool "Support for paging of anonymous memory (swap)"
depends on MMU
default y
help
This option allows you to choose whether you want to have support
for socalled swap devices or swap files in your kernel that are
used to provide more virtual memory than the actual RAM present
in your computer. If unsure say Y.
config SYSVIPC
bool "System V IPC"
---help---
Inter Process Communication is a suite of library functions and
system calls which let processes (running programs) synchronize and
exchange information. It is generally considered to be a good thing,
and some programs won't run unless you say Y here. In particular, if
you want to run the DOS emulator dosemu under Linux (read the
DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
you'll need to say Y here.
You can find documentation about IPC with "info ipc" and also in
section 6.4 of the Linux Programmer's Guide, available from
<http://www.tldp.org/guides.html>.
config POSIX_MQUEUE
bool "POSIX Message Queues"
depends on EXPERIMENTAL
---help---
POSIX variant of message queues is a part of IPC. In POSIX message
queues every message has a priority which decides about succession
of receiving it by a process. If you want to compile and run
programs written e.g. for Solaris with use of its POSIX message
queues (functions mq_*) say Y here. To use this feature you will
also need mqueue library, available from
<http://www.mat.uni.torun.pl/~wrona/posix_ipc/>
POSIX message queues are visible as a filesystem called 'mqueue'
and can be mounted somewhere if you want to do filesystem
operations on message queues.
If unsure, say Y.
config BSD_PROCESS_ACCT
bool "BSD Process Accounting"
help
If you say Y here, a user level program will be able to instruct the
kernel (via a special system call) to write process accounting
information to a file: whenever a process exits, information about
that process will be appended to the file by the kernel. The
information includes things such as creation time, owning user,
command name, memory usage, controlling terminal etc. (the complete
list is in the struct acct in <file:include/linux/acct.h>). It is
up to the user level program to do useful things with this
information. This is generally a good idea, so say Y.
config SYSCTL
bool "Sysctl support"
---help---
The sysctl interface provides a means of dynamically changing
certain kernel parameters and variables on the fly without requiring
a recompile of the kernel or reboot of the system. The primary
interface consists of a system call, but if you say Y to "/proc
file system support", a tree of modifiable sysctl entries will be
generated beneath the /proc/sys directory. They are explained in the
files in <file:Documentation/sysctl/>. Note that enabling this
option will enlarge the kernel by at least 8 KB.
As it is generally a good thing, you should say Y here unless
building a kernel for install/rescue disks or your system is very
limited in memory.
config AUDIT
bool "Auditing support"
default y if SECURITY_SELINUX
default n
help
Enable auditing infrastructure that can be used with another
kernel subsystem, such as SELinux (which requires this for
logging of avc messages output). Does not do system-call
auditing without CONFIG_AUDITSYSCALL.
config AUDITSYSCALL
bool "Enable system-call auditing support"
depends on AUDIT && (X86 || PPC64 || ARCH_S390)
default y if SECURITY_SELINUX
default n
help
Enable low-overhead system-call auditing infrastructure that
can be used independently or with another kernel subsystem,
such as SELinux.
config LOG_BUF_SHIFT
int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" if DEBUG_KERNEL
range 12 20
default 17 if ARCH_S390
default 16 if X86_NUMAQ || IA64
default 15 if SMP
default 14
help
Select kernel log buffer size as a power of 2.
Defaults and Examples:
17 => 128 KB for S/390
16 => 64 KB for x86 NUMAQ or IA-64
15 => 32 KB for SMP
14 => 16 KB for uniprocessor
13 => 8 KB
12 => 4 KB
config HOTPLUG
bool "Support for hot-pluggable devices" if !ARCH_S390
default ARCH_S390
help
Say Y here if you want to plug devices into your computer while
the system is running, and be able to use them quickly. In many
cases, the devices can likewise be unplugged at any time too.
One well known example of this is PCMCIA- or PC-cards, credit-card
size devices such as network cards, modems or hard drives which are
plugged into slots found on all modern laptop computers. Another
example, used on modern desktops as well as laptops, is USB.
Enable HOTPLUG and KMOD, and build a modular kernel. Get agent
software (at <http://linux-hotplug.sourceforge.net/>) and install it.
Then your kernel will automatically call out to a user mode "policy
agent" (/sbin/hotplug) to load modules and set up software needed
to use devices as you hotplug them.
config IKCONFIG
bool "Kernel .config support"
---help---
This option enables the complete Linux kernel ".config" file
contents, information on compiler used to build the kernel,
kernel running when this kernel was built and kernel version
from Makefile to be saved in the kernel. It provides documentation
of which kernel options are used in a running kernel or in an
on-disk kernel. This information can be extracted from the kernel
image file with the script scripts/extract-ikconfig and used as
input to rebuild the current kernel or to build another kernel.
It can also be extracted from a running kernel by reading
/proc/config.gz and /proc/config_built_with, if enabled (below).
/proc/config.gz will list the configuration that was used
to build the kernel and /proc/config_built_with will list
information on the compiler and host machine that was used to
build the kernel.
config IKCONFIG_PROC
bool "Enable access to .config through /proc/config.gz"
depends on IKCONFIG && PROC_FS
---help---
This option enables access to kernel configuration file and build
information through /proc/config.gz.
menuconfig EMBEDDED
bool "Configure standard kernel features (for small systems)"
help
This option allows certain base kernel options and settings
to be disabled or tweaked. This is for specialized
environments which can tolerate a "non-standard" kernel.
Only use this if you really know what you are doing.
config KALLSYMS
bool "Load all symbols for debugging/kksymoops" if EMBEDDED
default y
help
Say Y here to let the kernel print out symbolic crash information and
symbolic stack backtraces. This increases the size of the kernel
somewhat, as all symbols have to be loaded into the kernel image.
config KALLSYMS_ALL
bool "Include all symbols in kallsyms"
depends on DEBUG_KERNEL && KALLSYMS
help
Normally kallsyms only contains the symbols of functions, for nicer
OOPS messages. Some debuggers can use kallsyms for other
symbols too: say Y here to include all symbols, and you
don't care about adding 300k to the size of your kernel.
Say N.
config FUTEX
bool "Enable futex support" if EMBEDDED
default y
help
Disabling this option will cause the kernel to be built without
support for "fast userspace mutexes". The resulting kernel may not
run glibc-based applications correctly.
config EPOLL
bool "Enable eventpoll support" if EMBEDDED
default y
help
Disabling this option will cause the kernel to be built without
support for epoll family of system calls.
source "drivers/block/Kconfig.iosched"
config CC_OPTIMIZE_FOR_SIZE
bool "Optimize for size" if EMBEDDED
default y if ARM || H8300
default n
help
Enabling this option will pass "-Os" instead of "-O2" to gcc
resulting in a smaller kernel.
WARNING: some versions of gcc may generate incorrect code with this
option. If problems are observed, a gcc upgrade may be needed.
If unsure, say N.
endmenu # General setup
menu "Loadable module support"
config MODULES
bool "Enable loadable module support"
help
Kernel modules are small pieces of compiled code which can
be inserted in the running kernel, rather than being
permanently built into the kernel. You use the "modprobe"
tool to add (and sometimes remove) them. If you say Y here,
many parts of the kernel can be built as modules (by
answering M instead of Y where indicated): this is most
useful for infrequently used options which are not required
for booting. For more information, see the man pages for
modprobe, lsmod, modinfo, insmod and rmmod.
If you say Y here, you will need to run "make
modules_install" to put the modules under /lib/modules/
where modprobe can find them (you may need to be root to do
this).
If unsure, say Y.
config MODULE_UNLOAD
bool "Module unloading"
depends on MODULES
help
Without this option you will not be able to unload any
modules (note that some modules may not be unloadable
anyway), which makes your kernel slightly smaller and
simpler. If unsure, say Y.
config MODULE_FORCE_UNLOAD
bool "Forced module unloading"
depends on MODULE_UNLOAD && EXPERIMENTAL
help
This option allows you to force a module to unload, even if the
kernel believes it is unsafe: the kernel will remove the module
without waiting for anyone to stop using it (using the -f option to
rmmod). This is mainly for kernel developers and desperate users.
If unsure, say N.
config OBSOLETE_MODPARM
bool
default y
depends on MODULES
help
You need this option to use module parameters on modules which
have not been converted to the new module parameter system yet.
If unsure, say Y.
config MODVERSIONS
bool "Module versioning support (EXPERIMENTAL)"
depends on MODULES && EXPERIMENTAL
help
Usually, you have to use modules compiled with your kernel.
Saying Y here makes it sometimes possible to use modules
compiled for different kernels, by adding enough information
to the modules to (hopefully) spot any changes which would
make them incompatible with the kernel you are running. If
unsure, say N.
config KMOD
bool "Automatic kernel module loading"
depends on MODULES
help
Normally when you have selected some parts of the kernel to
be created as kernel modules, you must load them (using the
"modprobe" command) before you can use them. If you say Y
here, some parts of the kernel will be able to load modules
automatically: when a part of the kernel needs a module, it
runs modprobe with the appropriate arguments, thereby
loading the module if it is available. If unsure, say Y.
config STOP_MACHINE
bool
default y
depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
help
Need stop_machine() primitive.
endmenu