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#
# For a description of the syntax of this configuration file,
# see extra/config/Kconfig-language.txt
#
mainmenu "uClibc C Library Configuration"
config DESIRED_TARGET_ARCH
string
option env="ARCH"
choice
prompt "Target Architecture"
default TARGET_alpha if DESIRED_TARGET_ARCH = "alpha"
default TARGET_arm if DESIRED_TARGET_ARCH = "arm"
default TARGET_avr32 if DESIRED_TARGET_ARCH = "avr32"
default TARGET_bfin if DESIRED_TARGET_ARCH = "bfin"
default TARGET_cris if DESIRED_TARGET_ARCH = "cris"
default TARGET_e1 if DESIRED_TARGET_ARCH = "e1"
default TARGET_frv if DESIRED_TARGET_ARCH = "frv"
default TARGET_h8300 if DESIRED_TARGET_ARCH = "h8300"
default TARGET_hppa if DESIRED_TARGET_ARCH = "hppa"
default TARGET_i386 if DESIRED_TARGET_ARCH = "i386"
default TARGET_i960 if DESIRED_TARGET_ARCH = "i960"
default TARGET_ia64 if DESIRED_TARGET_ARCH = "ia64"
default TARGET_m68k if DESIRED_TARGET_ARCH = "m68k"
default TARGET_microblaze if DESIRED_TARGET_ARCH = "microblaze"
default TARGET_mips if DESIRED_TARGET_ARCH = "mips"
default TARGET_nios if DESIRED_TARGET_ARCH = "nios"
default TARGET_nios2 if DESIRED_TARGET_ARCH = "nios2"
default TARGET_powerpc if DESIRED_TARGET_ARCH = "powerpc"
default TARGET_sh if DESIRED_TARGET_ARCH = "sh"
default TARGET_sh64 if DESIRED_TARGET_ARCH = "sh64"
default TARGET_sparc if DESIRED_TARGET_ARCH = "sparc"
default TARGET_v850 if DESIRED_TARGET_ARCH = "v850"
default TARGET_vax if DESIRED_TARGET_ARCH = "vax"
default TARGET_x86_64 if DESIRED_TARGET_ARCH = "x86_64"
default TARGET_xtensa if DESIRED_TARGET_ARCH = "xtensa"
help
The architecture of your target.
config TARGET_alpha
bool "alpha"
config TARGET_arm
bool "arm"
config TARGET_avr32
bool "avr32"
config TARGET_bfin
bool "bfin"
config TARGET_cris
bool "cris"
config TARGET_e1
bool "e1 (BROKEN)"
config TARGET_frv
bool "frv (BROKEN)"
config TARGET_h8300
bool "h8300 (BROKEN)"
config TARGET_hppa
bool "hppa"
config TARGET_i386
bool "i386"
config TARGET_i960
bool "i960 (BROKEN)"
config TARGET_ia64
bool "ia64"
config TARGET_m68k
bool "m68k"
config TARGET_microblaze
bool "microblaze (BROKEN)"
config TARGET_mips
bool "mips"
config TARGET_nios
bool "nios"
config TARGET_nios2
bool "nios2"
config TARGET_powerpc
bool "powerpc"
config TARGET_sh
bool "superh"
config TARGET_sh64
bool "sh64"
config TARGET_sparc
bool "sparc"
config TARGET_v850
bool "v850 (BROKEN)"
config TARGET_vax
bool "vax"
config TARGET_x86_64
bool "x86_64"
config TARGET_xtensa
bool "xtensa"
endchoice
menu "Target Architecture Features and Options"
if TARGET_alpha
source "extra/Configs/Config.alpha"
endif
if TARGET_arm
source "extra/Configs/Config.arm"
endif
if TARGET_avr32
source "extra/Configs/Config.avr32"
endif
if TARGET_bfin
source "extra/Configs/Config.bfin"
endif
if TARGET_cris
source "extra/Configs/Config.cris"
endif
if TARGET_e1
source "extra/Configs/Config.e1"
endif
if TARGET_frv
source "extra/Configs/Config.frv"
endif
if TARGET_h8300
source "extra/Configs/Config.h8300"
endif
if TARGET_hppa
source "extra/Configs/Config.hppa"
endif
if TARGET_i386
source "extra/Configs/Config.i386"
endif
if TARGET_i960
source "extra/Configs/Config.i960"
endif
if TARGET_ia64
source "extra/Configs/Config.ia64"
endif
if TARGET_m68k
source "extra/Configs/Config.m68k"
endif
if TARGET_nios
source "extra/Configs/Config.nios"
endif
if TARGET_nios2
source "extra/Configs/Config.nios2"
endif
if TARGET_microblaze
source "extra/Configs/Config.microblaze"
endif
if TARGET_mips
source "extra/Configs/Config.mips"
endif
if TARGET_powerpc
source "extra/Configs/Config.powerpc"
endif
if TARGET_sh
source "extra/Configs/Config.sh"
endif
if TARGET_sh64
source "extra/Configs/Config.sh64"
endif
if TARGET_sparc
source "extra/Configs/Config.sparc"
endif
if TARGET_v850
source "extra/Configs/Config.v850"
endif
if TARGET_vax
source "extra/Configs/Config.vax"
endif
if TARGET_x86_64
source "extra/Configs/Config.x86_64"
endif
if TARGET_xtensa
source "extra/Configs/Config.xtensa"
endif
config TARGET_SUBARCH
string
default "e500" if CONFIG_E500
default "classic" if CONFIG_CLASSIC
default "sh4" if CONFIG_SH4
default ""
source "extra/Configs/Config.in.arch"
endmenu
menu "General Library Settings"
config HAVE_NO_PIC
bool
default n
config DOPIC
bool "Generate only Position Independent Code (PIC)"
default y
depends on !HAVE_NO_PIC
help
If you wish to build all of uClibc as PIC objects, then answer Y here.
If you are unsure, then you should answer N.
config ARCH_HAS_NO_SHARED
bool
default n
config ARCH_HAS_NO_LDSO
bool
select ARCH_HAS_NO_SHARED
default n
config HAVE_SHARED
bool "Enable support for shared libraries"
depends on !ARCH_HAS_NO_SHARED
default y
help
If you wish to build uClibc with support for shared libraries then
answer Y here. If you only want to build uClibc as a static library,
then answer N.
config FORCE_SHAREABLE_TEXT_SEGMENTS
bool "Only load shared libraries which can share their text segment"
depends on HAVE_SHARED
select DOPIC
default n
help
If you answer Y here, the uClibc native shared library loader will
only load shared libraries, which do not need to modify any
non-writable segments. These libraries haven't set the DT_TEXTREL
tag in the dynamic section (==> objdump).
All your libraries must be compiled with -fPIC or -fpic, and all
assembler function must be written as position independent code (PIC).
Enabling this option will make uClibc's shared library loader a
little bit smaller and guarantee that no memory will be wasted by
badly coded shared libraries.
config LDSO_LDD_SUPPORT
bool "Native 'ldd' support"
depends on HAVE_SHARED
default y
help
Enable all the code needed to support traditional ldd,
which executes the shared library loader to resolve all dependencies
and then provide a list of shared libraries that are required for an
application to function. Disabling this option will makes uClibc's
shared library loader a little bit smaller.
Most people will answer Y.
config LDSO_CACHE_SUPPORT
bool "Enable library loader cache (ld.so.conf)"
depends on HAVE_SHARED
default y
help
Enable this to make use of /etc/ld.so.conf, the shared library loader
cache configuration file to support for non-standard library paths.
After updating this file, it is necessary to run 'ldconfig' to update
the /etc/ld.so.cache shared library loader cache file.
config LDSO_PRELOAD_FILE_SUPPORT
bool "Enable library loader preload file (ld.so.preload)"
depends on HAVE_SHARED
default n
help
Enable this to make use of /etc/ld.so.preload. This file contains a
whitespace separated list of shared libraries to be loaded before
the program.
config LDSO_BASE_FILENAME
string "Shared library loader naming prefix"
depends on HAVE_SHARED && (LDSO_CACHE_SUPPORT || LDSO_PRELOAD_FILE_SUPPORT)
default "ld.so"
help
If you wish to support both uClibc and glibc on the same system, it
is necessary to set this to something other than "ld.so" to avoid
conflicts with glibc, which also uses "ld.so". This prevents both
libraries from using the same /etc/ld.so.* files. If you wish to
support both uClibc and glibc on the same system then you should set
this to "ld-uClibc.so".
Most people will leave this set to the default of "ld.so".
WARNING: Changing the default prefix could cause problems with
binutils' ld !
config UCLIBC_STATIC_LDCONFIG
bool "Link ldconfig statically"
depends on HAVE_SHARED
default y
help
Enable this option to statically link the ldconfig binary.
Making ldconfig static can be beneficial if you have a library
problem and need to use ldconfig to recover. Sometimes it is
preferable to instead keep the size of the system down, in which
case you should disable this option.
config LDSO_RUNPATH
bool "Enable ELF RUNPATH tag support"
depends on HAVE_SHARED
default y if LDSO_CACHE_SUPPORT
default n if !LDSO_CACHE_SUPPORT
help
ELF's may have dynamic RPATH/RUNPATH tags. These tags list paths
which extend the library search paths. They are really only useful
if a package installs libraries in non standard locations and
ld.so.conf support is disabled.
Usage of RUNPATH tags is not too common, so disabling this feature
should be safe for most people.
config LDSO_SEARCH_INTERP_PATH
bool "Add ldso path to lib search path"
depends on HAVE_SHARED
default y
help
The ldso is told where it is being executed from and can use that
path to find related core libraries. This is useful by default,
but can be annoying in a mixed development environment.
i.e. if the ldso is run from /foo/boo/ldso.so, it will start its
library search with /foo/boo/
If unsure, simply say Y here.
config UCLIBC_CTOR_DTOR
bool "Support global constructors and destructors"
default y
help
If you wish to build uClibc with support for global constructor
(ctor) and global destructor (dtor) support, then answer Y here.
When ctor/dtor support is enabled, binaries linked with uClibc must
also be linked with crtbegin.o and crtend.o which are provided by gcc
(the "*startfile:" and "*endfile:" settings in your gcc specs file
may need to be adjusted to include these files). This support will
also add a small amount of additional size to each binary compiled vs
uClibc. If you will be using uClibc with C++, or if you need the gcc
__attribute__((constructor)) and __attribute__((destructor)) to work,
then you definitely want to answer Y here. If you don't need ctors
or dtors and want your binaries to be as small as possible, then
answer N.
config LDSO_GNU_HASH_SUPPORT
bool "Enable GNU hash style support"
depends on HAVE_SHARED
default n
help
Newest binutils support a new hash style named GNU-hash. The dynamic
linker will use the new GNU-hash section (.gnu.hash) for symbol lookup
if present into the ELF binaries, otherwise it will use the old SysV
hash style (.hash). This ensures that it is completely backward
compatible.
Further, being the hash table implementation self-contained into each
executable and shared libraries, objects with mixed hash style can
peacefully coexist in the same process.
If you want to use this new feature, answer Y
choice
prompt "Thread support"
#default UCLIBC_HAS_THREADS_NATIVE if (TARGET_alpha || TARGET_arm || TARGET_i386 || TARGET_mips || TARGET_powerpc || TARGET_sh || TARGET_sh64)
default HAS_NO_THREADS
help
If you want to compile uClibc with pthread support, then answer Y.
This will increase the size of uClibc by adding a bunch of locking
to critical data structures, and adding extra code to ensure that
functions are properly reentrant.
config HAS_NO_THREADS
bool "none"
help
Disable thread support.
config LINUXTHREADS_OLD
bool "older (stable) version of linuxthreads"
# linuxthreads and linuxthreads.old need nanosleep()
select UCLIBC_HAS_REALTIME
help
There are two versions of linuxthreads. The older (stable) version
has been in uClibc for quite a long time but hasn't seen too many
updates other than bugfixes.
config LINUXTHREADS_NEW
bool "slightly newer version of linuxthreads"
help
The new version has not been tested much, and lacks ports for arches
which glibc does not support (like bfin/frv/etc...), but is based on
the latest code from glibc, so it may be the only choice for the
newer ports (like alpha/amd64/64bit arches and hppa).
config UCLIBC_HAS_THREADS_NATIVE
bool "Native POSIX Threading (NPTL)"
select UCLIBC_HAS_TLS
help
If you want to compile uClibc with NPTL support, then answer Y.
IMPORTANT NOTE! NPTL requires a Linux 2.6 kernel, binutils
at least version 2.16 and GCC with at least version 4.1.0. NPTL
will not work with older versions of any above sources. If you
ignore any of these guidelines, you do so at your own risk. Do
not ask for help on any of the development mailing lists.
!!!! WARNING !!!! BIG FAT WARNING !!!! REALLY BIG FAT WARNING !!!!
This is experimental code and at times it may not even build and
even if it does it might decide to do random damage. This code is
potentially hazardous to your health and sanity. It will remain
that way until further notice at which point this notice will
disappear. Thank you for your support and for not smoking.
endchoice
config UCLIBC_HAS_THREADS
def_bool y if !HAS_NO_THREADS
config UCLIBC_HAS_TLS
bool "Thread-Local Storage"
depends on UCLIBC_HAS_THREADS_NATIVE
default n
help
If you want to enable TLS support then answer Y.
This is fast an efficient way to store per-thread local data
which is not on stack. It needs __thread support enabled in
gcc.
config PTHREADS_DEBUG_SUPPORT
bool "Build pthreads debugging support"
default n
depends on UCLIBC_HAS_THREADS
help
Say Y here if you wish to be able to debug applications that use
uClibc's pthreads library. By enabling this option, a library
named libthread_db will be built. This library will be dlopen()'d
by gdb and will allow gdb to debug the threads in your application.
IMPORTANT NOTE! Because gdb must dlopen() the libthread_db library,
you must compile gdb with uClibc in order for pthread debugging to
work properly.
If you are doing development and want to debug applications using
uClibc's pthread library, answer Y. Otherwise, answer N.
config UCLIBC_HAS_SYSLOG
bool "Syslog support"
default y
depends on UCLIBC_HAS_NETWORK_SUPPORT
select UCLIBC_HAS_SOCKET
help
Support sending messages to the system logger.
This requires socket-support.
config UCLIBC_HAS_LFS
bool "Large File Support"
default y
help
If you wish to build uClibc with support for accessing large files
(i.e. files greater then 2 GiB) then answer Y. Do not enable this
if you are using an older Linux kernel (2.0.x) that lacks large file
support. Enabling this option will increase the size of uClibc.
choice
prompt "Malloc Implementation"
default MALLOC if ! ARCH_USE_MMU
default MALLOC_STANDARD if ARCH_USE_MMU
config MALLOC
bool "malloc"
help
"malloc" use mmap for all allocations and so works very well on
MMU-less systems that do not support the brk() system call. It is
pretty smart about reusing already allocated memory, and minimizing
memory wastage.
This is the default for uClinux MMU-less systems.
config MALLOC_SIMPLE
bool "malloc-simple"
help
"malloc-simple" is trivially simple and slow as molasses. It
was written from scratch for uClibc, and is the simplest possible
(and therefore smallest) malloc implementation.
This uses only the mmap() system call to allocate and free memory,
and does not use the brk() system call at all, making it a fine
choice for MMU-less systems with very limited memory. It's 100%
standards compliant, thread safe, very small, and releases freed
memory back to the OS immediately rather than keeping it in the
process's heap for reallocation. It is also VERY SLOW.
config MALLOC_STANDARD
bool "malloc-standard"
depends on ARCH_USE_MMU
help
"malloc-standard" is derived from the public domain dlmalloc
implementation by Doug Lea. It is quite fast, and is pretty smart
about reusing already allocated memory, and minimizing memory
wastage. This uses brk() for small allocations, while using mmap()
for larger allocations. This is the default malloc implementation
for uClibc.
If unsure, answer "malloc-standard".
endchoice
config MALLOC_GLIBC_COMPAT
bool "Malloc returns live pointer for malloc(0)"
default n
help
The behavior of malloc(0) is listed as implementation-defined by
SuSv3. Glibc returns a valid pointer to something, while uClibc
normally returns NULL. I personally feel glibc's behavior is
not particularly safe, and allows buggy applications to hide very
serious problems.
When this option is enabled, uClibc will act just like glibc, and
return a live pointer when someone calls malloc(0). This pointer
provides a malloc'ed area with a size of 1 byte. This feature is
mostly useful when dealing with applications using autoconf's broken
AC_FUNC_MALLOC macro (which redefines malloc as rpl_malloc if it
does not detect glibc style returning-a-valid-pointer-for-malloc(0)
behavior). Most people can safely answer N.
config UCLIBC_DYNAMIC_ATEXIT
bool "Dynamic atexit() Support"
default y
help
When this option is enabled, uClibc will support an infinite number,
of atexit() and on_exit() functions, limited only by your available
memory. This can be important when uClibc is used with C++, since
global destructors are implemented via atexit(), and it is quite
possible to exceed the default number when this option is disabled.
Enabling this option adds a few bytes, and more significantly makes
atexit and on_exit depend on malloc, which can be bad when compiling
static executables.
Unless you use uClibc with C++, you should probably answer N.
config COMPAT_ATEXIT
bool "Old (visible) atexit Support"
default n
help
Enable this option if you want to update from 0.9.28 to git/0.9.29,
else you will be missing atexit() until you rebuild all apps.
config UCLIBC_SUSV3_LEGACY
bool "Enable SuSv3 LEGACY functions"
default n
#vfork,
# h_errno
# gethostbyaddr
# gethostbyname
help
Enable this option if you want to have SuSv3 LEGACY functions
in the library, else they are replaced by SuSv3 proposed macros.
Currently applies to:
bcmp, bcopy, bzero, index, rindex, ftime,
bsd_signal, (ecvt), (fcvt), gcvt, (getcontext),
(getwd), (makecontext),
mktemp, (pthread_attr_getstackaddr), (pthread_attr_setstackaddr),
scalb, (setcontext), (swapcontext), ualarm, usleep,
wcswcs.
WARNING! ABI incompatibility.
config UCLIBC_SUSV3_LEGACY_MACROS
bool "Enable SuSv3 LEGACY macros"
default n
help
Enable this option if you want to have SuSv3 LEGACY macros.
Currently applies to bcopy/bzero/bcmp/index/rindex et al.
WARNING! ABI incompatibility.
config UCLIBC_SUSV4_LEGACY
bool "Enable SuSv4 LEGACY or obsolescent functions"
default n
help
Enable this option if you want to have SuSv4 LEGACY functions
and macros in the library.
Currently applies to:
- XSI functions:
_longjmp, _setjmp, _tolower, _toupper, ftw, getitimer,
gettimeofday, isascii, pthread_getconcurrency,
pthread_setconcurrency, setitimer, setpgrp, sighold,
sigignore, sigpause, sigrelse, sigset, siginterrupt,
tempnam, toascii, ulimit.
- Base functions:
asctime, asctime_r, ctime, ctime_r, gets, rand_r,
tmpnam, utime.
WARNING! ABI incompatibility.
config UCLIBC_HAS_STUBS
bool "Provide stubs for unavailable functionality"
default n
help
With this option uClibc provides non-functional stubs for
functions which are impossible to implement on the target
architecture. Otherwise, such functions are simply omitted.
As of 2008-07, this option makes uClibc provide fork() stub
on NOMMU targets. It always sets errno to ENOSYS and returns -1.
This may be useful if you port a lot of software and cannot
audit all of it and replace or disable fork() usage.
With this option, a program which uses fork() will build
successfully. Of course, it may be useless if fork()
is essential for its operation.
config UCLIBC_HAS_SHADOW
bool "Shadow Password Support"
default y
help
Answer N if you do not need shadow password support.
Most people will answer Y.
config UCLIBC_HAS_PROGRAM_INVOCATION_NAME
bool "Support for program_invocation_name"
default n
help
Support for the GNU-specific program_invocation_name and
program_invocation_short_name strings. Some GNU packages
(like tar and coreutils) utilize these for extra useful
output, but in general are not required.
At startup, these external strings are automatically set
up based on the value of ARGV[0].
If unsure, just answer N.
config UCLIBC_HAS___PROGNAME
bool "Support for __progname"
default y
depends on UCLIBC_HAS_PROGRAM_INVOCATION_NAME
help
Some packages (like openssh) like to peek into internal libc
symbols to make their output a bit more user friendly.
At startup, __progname is automatically set up based on the
value of ARGV[0].
If unsure, just answer N.
config UCLIBC_HAS_PTY
bool "Support for pseudo-terminals"
default y
help
This enables support for pseudo-terminals (see man 4 pts
and man 7 pty).
If unsure, just answer Y.
config ASSUME_DEVPTS
bool "Assume that /dev/pts is a devpts or devfs file system"
default y
depends on UCLIBC_HAS_PTY
help
Enable this if /dev/pts is on a devpts or devfs filesystem. Both
these filesystems automatically manage permissions on the /dev/pts
devices. You may need to mount your devpts or devfs filesystem on
/dev/pts for this to work.
Most people should answer Y.
config UNIX98PTY_ONLY
bool "Support only Unix 98 PTYs"
default y
depends on UCLIBC_HAS_PTY
help
If you want to support only Unix 98 PTYs enable this. Some older
applications may need this disabled and will thus use legacy BSD
style PTY handling which is more complex and also bigger than
Unix 98 PTY handling.
For most current programs, you can generally answer Y.
if UNIX98PTY_ONLY
config UCLIBC_HAS_GETPT
bool "Support getpt() (glibc-compat)"
default n
depends on UCLIBC_HAS_PTY
help
Some packages may need getpt().
All of those are non-standard and can be considered
GNU/libc compatibility.
Either use posix_openpt() or just open /dev/ptmx yourself.
If unsure, just say N.
endif
if !UNIX98PTY_ONLY
# Have to use __libc_ptyname{1,2}[] and related bloat
config UCLIBC_HAS_GETPT
def_bool y
endif
config UCLIBC_HAS_LIBUTIL
bool "Provide libutil library and functions"
depends on UCLIBC_HAS_PTY
default n
help
Provide a libutil library.
This non-standard conforming library provides the following
utility functions:
forkpty(): combines openpty(), fork(2), and login_tty() to
create a new process operating in a pseudo-terminal.
login(): write utmp and wtmp entries
login_tty(): prepares for a login on the tty fd by creating a
new session, making fd the controlling terminal for
the calling process, setting fd to be the standard
input, output, and error streams of the current
process, and closing fd.
logout(): write utmp and wtmp entries
logwtmp(): constructs a utmp structure and calls updwtmp() to
append the structure to the utmp file.
openpty(): finds an available pseudo-terminal and returns
file descriptors for the master and slave
This library adds about 3k-4k to your system.
config UCLIBC_HAS_TM_EXTENSIONS
bool "Support 'struct tm' timezone extension fields"
default y
help
Enabling this option adds fields to 'struct tm' in time.h for
tracking the number of seconds east of UTC, and an abbreviation for
the current timezone. These fields are not specified by the SuSv3
standard, but they are commonly used in both GNU and BSD application
code.
To strictly follow the SuSv3 standard, leave this disabled.
Most people will probably want to answer Y.
config UCLIBC_HAS_TZ_CACHING
bool "Enable caching of the last valid timezone 'TZ' string"
default y
help
Answer Y to enable caching of the last valid 'TZ' string describing
the timezone setting. This allows a quick string compare to avoid
repeated parsing of unchanged 'TZ' strings when tzset() is called.
Most people will answer Y.
config UCLIBC_HAS_TZ_FILE
bool "Enable '/etc/TZ' file support to set a default timezone (uClibc-specific)"
default y
help
Answer Y to enable the setting of a default timezone for uClibc.
Ordinarily, uClibc gets the timezone information exclusively from the
'TZ' environment variable. In particular, there is no support for
the zoneinfo directory tree or the /etc/timezone file used by glibc.
With this option enabled, uClibc will use the value stored in the
file '/etc/TZ' (default path) to obtain timezone information if the
'TZ' environment variable is missing or has an invalid value. The
file consists of a single line (newline required) of text describing
the timezone in the format specified for the TZ environment variable.
Doing 'echo CST6CDT > /etc/TZ' is enough to create a valid file.
See
http://www.opengroup.org/onlinepubs/007904975/basedefs/xbd_chap08.html
for details on valid settings of 'TZ'.
Most people will answer Y.
config UCLIBC_HAS_TZ_FILE_READ_MANY
bool "Repeatedly read the '/etc/TZ' file"
depends on UCLIBC_HAS_TZ_FILE
default y
help
Answer Y to enable repeated reading of the '/etc/TZ' file even after
a valid value has been read. This incurs the overhead of an
open/read/close for each tzset() call (explicit or implied). However,
setting this will allow applications to update their timezone
information if the contents of the file change.
Most people will answer Y.
config UCLIBC_TZ_FILE_PATH
string "Path to the 'TZ' file for setting the global timezone"
depends on UCLIBC_HAS_TZ_FILE
default "/etc/TZ"
help
This is the path to the 'TZ' file.
Most people will use the default of '/etc/TZ'.
endmenu
menu "Advanced Library Settings"
config UCLIBC_PWD_BUFFER_SIZE
int "Buffer size for getpwnam() and friends"
default 256
range 12 1024
help
This sets the value of the buffer size for getpwnam() and friends.
By default, this is 256. (For reference, glibc uses 1024).
The value can be found using sysconf() with the _SC_GETPW_R_SIZE_MAX
parameter.
config UCLIBC_GRP_BUFFER_SIZE
int "Buffer size for getgrnam() and friends"
default 256
range 12 1024
help
This sets the value of the buffer size for getgrnam() and friends.
By default, this is 256. (For reference, glibc uses 1024).
The value can be found using sysconf() with the _SC_GETGR_R_SIZE_MAX
parameter.
comment "Support various families of functions"
config UCLIBC_LINUX_MODULE_24
bool "Linux kernel module functions"
default !(TARGET_bfin)
help
create_module, query_module
are used in linux (prior to 2.6) for loadable kernel modules.
Say N if you do not use kernel modules, or you only support
Linux 2.6+.
config UCLIBC_LINUX_SPECIFIC
bool "Linux specific functions"
default y
help
capget(), capset(), fstatfs(), inotify_*(), ioperm(), iopl(),
madvise(), modify_ldt(), personality(), prctl()/arch_prctl(),
ppoll(), readahead(), reboot(), remap_file_pages(),
sched_getaffinity(), sched_setaffinity(), sendfile(),
setfsgid(), setfsuid(), setresuid(),
splice(), vmsplice(), tee(), signalfd(), swapoff(), swapon(),
sync_file_range(), sysctl(), sysinfo(), vhangup()
config UCLIBC_HAS_GNU_ERROR
bool "Support GNU extensions for error-reporting"
default y
help
Support for the GNU-specific error(), error_at_line(),
void (* error_print_progname)(), error_message_count
functions and variables. Some GNU packages
utilize these for extra useful output, but in general
are not required.
If unsure, just answer N.
config UCLIBC_BSD_SPECIFIC
bool "BSD specific functions"
default y
help
mincore(), getdomainname(), setdomainname()
If unsure, say N.
config UCLIBC_HAS_BSD_ERR
bool "BSD err functions"
default y
help
These functions are non-standard BSD extensions.
err(), errx(), warn(), warnx(), verr(), verrx(), vwarn(), vwarnx()
If unsure, say N.
config UCLIBC_HAS_OBSOLETE_BSD_SIGNAL
bool "BSD obsolete signal functions"
default n
help
These functions are provided as a compatibility interface for
programs that make use of the historical System V signal API.
This API is obsolete:
new applications should use the POSIX signal API (sigaction(2),
sigprocmask(2), etc.).
Affected functions:
sigset(), sighold(), sigrelse(), sigignore()
If unsure, say N.
config UCLIBC_HAS_OBSOLETE_SYSV_SIGNAL
bool "SYSV obsolete signal functions"
default n
help
Use of sysv_signal() should be avoided; use sigaction(2) instead.
If unsure, say N.
config UCLIBC_NTP_LEGACY
bool "ntp_*() aliases"
default n
help
Provide legacy aliases for ntp functions:
ntp_adjtime(), ntp_gettime()
It is safe to say N here.
config UCLIBC_SV4_DEPRECATED
bool "Enable SVr4 deprecated functions"
default n
help
These functions are DEPRECATED in System V release 4.
Say N unless you desparately need one of the functions below:
ustat() [use statfs(2) in your code instead]
config UCLIBC_HAS_REALTIME
bool "Realtime-related family of SUSv functions"
default y
help
These functions are part of the Timers option and need not
be available on all implementations.
Includes AIO, message-queue, scheduler, semaphore functions:
aio.h
mqueue.h
sched.h
semaphore.h
aio_cancel()
aio_error()
aio_fsync()
aio_read()
lio_listio()
aio_return()
aio_suspend()
aio_write()
clock_getres(), clock_gettime(), clock_settime()
fdatasync()
mlockall(), munlockall()
mlock(), munlock()
mq_close()
mq_getattr()
mq_notify()
mq_open()
mq_receive()
mq_send()
mq_setattr()
mq_unlink()
nanosleep()
sched_getparam()
sched_get_priority_max(), sched_get_priority_min()
sched_getscheduler()
sched_rr_get_interval()
sched_setparam()
sched_setscheduler()
sem_close()
sem_destroy()
sem_getvalue()
sem_init()
sem_open()
sem_post()
sem_trywait(), sem_wait()
sem_unlink()
sigqueue()
sigtimedwait(), sigwaitinfo()
timer_create()
timer_delete()
timer_getoverrun(), timer_gettime(), timer_settime()
config UCLIBC_HAS_ADVANCED_REALTIME
bool "Advanced realtime-related family of SUSv functions"
default y
depends on UCLIBC_HAS_REALTIME
help
These functions are part of the Timers option and need not
be available on all implementations.
clock_getcpuclockid()
clock_nanosleep()
mq_timedreceive()
mq_timedsend()
posix_fadvise()
posix_fallocate()
posix_madvise()
posix_memalign()
posix_mem_offset()
posix_spawnattr_destroy(), posix_spawnattr_init()
posix_spawnattr_getflags(), posix_spawnattr_setflags()
posix_spawnattr_getpgroup(), posix_spawnattr_setpgroup()
posix_spawnattr_getschedparam(), posix_spawnattr_setschedparam()
posix_spawnattr_getschedpolicy(), posix_spawnattr_setschedpolicy()
posix_spawnattr_getsigdefault(), posix_spawnattr_setsigdefault()
posix_spawnattr_getsigmask(), posix_spawnattr_setsigmask()
posix_spawn_file_actions_addclose()
posix_spawn_file_actions_adddup2()
posix_spawn_file_actions_addopen()
posix_spawn_file_actions_destroy()
posix_spawn_file_actions_init()
posix_spawn()
posix_spawnp()
posix_typed_mem_get_info()
pthread_mutex_timedlock()
sem_timedwait()
#config UCLIBC_HAS_TERMIOS
# bool "termios functions"
# default y
# help
# Get and set terminal attributes, line control, get and set baud
# rate.
# termios(), tcgetattr(), tcsetattr(), tcsendbreak(), tcdrain(),
# tcflush(), tcflow(), cfmakeraw(), cfgetospeed(), cfgetispeed(),
# cfsetispeed(), cfsetospeed(), cfsetspeed()
#
# If unsure, say Y.
config UCLIBC_HAS_EPOLL
bool "epoll"
default y
help
epoll_create(), epoll_ctl(), epoll_wait() functions.
config UCLIBC_HAS_XATTR
bool "Extended Attributes"
default y
help
Extended Attributes support.
setxattr()
lsetxattr()
fsetxattr()
getxattr()
lgetxattr()
fgetxattr()
listxattr()
llistxattr()
flistxattr()
removexattr()
lremovexattr()
fremovexattr()
Say N unless you need support for extended attributes and the
filesystems do actually support them.
config UCLIBC_HAS_PROFILING
bool "Profiling support"
default y
help
gcc's -finstrument-functions needs these.
Most people can safely answer N.
config UCLIBC_HAS_CRYPT_IMPL
bool "libcrypt support"
default y
help
libcrypt contains crypt(), setkey() and encrypt()
config UCLIBC_HAS_CRYPT_STUB
bool "libcrypt stubs"
default y
depends on !UCLIBC_HAS_CRYPT_IMPL
help
Standards mandate that crypt(3) provides a stub if it is unavailable.
If you enable this option then stubs for
crypt(), setkey() and encrypt()
will be provided in a small libcrypt.
config UCLIBC_HAS_CRYPT
def_bool y
depends on UCLIBC_HAS_CRYPT_IMPL || UCLIBC_HAS_CRYPT_STUB
endmenu
menuconfig UCLIBC_HAS_NETWORK_SUPPORT
bool "Networking Support"
default y
help
Say N here if you do not need network support.
if UCLIBC_HAS_NETWORK_SUPPORT
config UCLIBC_HAS_SOCKET
bool "Socket support"
default y
help
If you want to include support for sockets then answer Y.
config UCLIBC_HAS_IPV4
bool "IP version 4 support"
default y
select UCLIBC_HAS_SOCKET
help
If you want to include support for the Internet Protocol
(IP version 4) then answer Y.
Most people will say Y.
config UCLIBC_HAS_IPV6
bool "IP version 6 support"
default n
select UCLIBC_HAS_SOCKET
help
If you want to include support for the next version of the Internet
Protocol (IP version 6) then answer Y.
Most people should answer N.
config UCLIBC_HAS_RPC
bool "Remote Procedure Call (RPC) support"
default n
# RPC+socket-ipvX doesn't currently work.
depends on UCLIBC_HAS_IPV4 || UCLIBC_HAS_IPV6
help
If you want to include RPC support, enable this. RPC is rarely used
for anything except for the NFS filesystem. Unless you plan to use
NFS, you can probably leave this set to N and save some space.
If you need to use NFS then you should answer Y.
config UCLIBC_HAS_FULL_RPC
bool "Full RPC support"
depends on UCLIBC_HAS_RPC
default y if !HAVE_SHARED
help
Normally we enable just enough RPC support for things like rshd and
nfs mounts to work. If you find you need the rest of the RPC stuff,
then enable this option. Most people can safely answer N.
config UCLIBC_HAS_REENTRANT_RPC
bool "Reentrant RPC support"
depends on UCLIBC_HAS_RPC
default y if !HAVE_SHARED
help
Most packages utilize the normal (non-reentrant) RPC functions, but
some (like exportfs from nfs-utils) need these reentrant versions.
Most people can safely answer N.
config UCLIBC_USE_NETLINK
bool "Use netlink to query interfaces"
default n
depends on UCLIBC_HAS_SOCKET
help
In newer versions of Linux (2.4.17+), support was added for querying
network device information via netlink rather than the old style
ioctl's. Most of the time, the older ioctl style is sufficient (and
it is smaller than netlink), but if you find that not all of your
devices are being returned by the if_nameindex() function, you will
have to use the netlink implementation.
Most people can safely answer N.
config UCLIBC_SUPPORT_AI_ADDRCONFIG
bool "Support the AI_ADDRCONFIG flag"
depends on UCLIBC_USE_NETLINK
default n
help
The implementation of AI_ADDRCONFIG is aligned with the glibc
implementation using netlink to query interfaces to find both
ipv4 and ipv6 support. This is only needed if an application uses
the AI_ADDRCONFIG flag.
Most people can safely answer N.
config UCLIBC_HAS_BSD_RES_CLOSE
bool "Support res_close() (bsd-compat)"
default n
help
Answer Y if you desperately want to support BSD compatibility in
the network code.
Most people will say N.
config UCLIBC_HAS_COMPAT_RES_STATE
bool "Use compatible but bloated _res"
default y
help
Answer Y if you build network utilities and they muck with resolver
internals a lot (_res global structure). uclibc does not use most
of _res.XXX fields, and with this option OFF they won't even exist.
Which will make e.g. dig build fail.
Answering N saves around 400 bytes in bss.
config UCLIBC_HAS_EXTRA_COMPAT_RES_STATE
bool "Use extra compatible but extra bloated _res"
default n
help
Answer Y if selecting UCLIBC_HAS_COMPAT_RES_STATE is not enough.
As far as I can say, this should never be needed.
config UCLIBC_HAS_LIBRESOLV_STUB
bool "Provide libresolv stub"
default n
help
Provide a dummy resolv library.
config UCLIBC_HAS_LIBNSL_STUB
bool "Provide libnsl stub"
default n
help
Provide a dummy nsl library.
endif
menu "String and Stdio Support"
config UCLIBC_HAS_STRING_GENERIC_OPT
bool "Use faster (but larger) generic string functions"
default y
help
Answer Y to use the (tweaked) glibc generic string functions.
In general, they are faster (but 3-5K larger) than the base
uClibc string functions which are optimized solely for size.
Many people will answer Y.
config UCLIBC_HAS_STRING_ARCH_OPT
bool "Use arch-specific assembly string functions (where available)"
default y
help
Answer Y to use any archtecture-specific assembly language string
functions available for this target plaform.
Note that assembly implementations are not available for all string
functions, so some generic (written in C) string functions may
still be used.
These are small and fast, the only reason _not_ to say Y here is
for debugging purposes.
config UCLIBC_HAS_CTYPE_TABLES
bool "Use Table Versions Of 'ctype.h' Functions."
default y
help
Answer Y to use table versions of the 'ctype.h' functions.
While the non-table versions are often smaller when building
statically linked apps, they work only in stub locale mode.
Most people will answer Y.
config UCLIBC_HAS_CTYPE_SIGNED
bool "Support Signed Characters In 'ctype.h' Functions."
depends on UCLIBC_HAS_CTYPE_TABLES
default y
help
Answer Y to enable support for passing signed char values to
the 'ctype.h' functions. ANSI/ISO C99 and SUSv3 specify that
these functions are only defined for unsigned char values and
EOF. However, glibc allows negative signed char values as well
in order to support 'broken old programs'.
Most people will answer Y.
choice
prompt "ctype argument checking"
depends on UCLIBC_HAS_CTYPE_TABLES
default UCLIBC_HAS_CTYPE_UNSAFE
help
Please select the invalid arg behavior you want for the 'ctype'
functions.
The 'ctype' functions are now implemented using table lookups, with
the arg being the index. This can result in incorrect memory accesses
or even segfaults for args outside of the allowed range.
NOTE: This only affects the 'ctype' _functions_. It does not affect
the macro implementations.
config UCLIBC_HAS_CTYPE_UNSAFE
bool "Do not check -- unsafe"
config UCLIBC_HAS_CTYPE_CHECKED
bool "Detect and handle appropriately"
config UCLIBC_HAS_CTYPE_ENFORCED
bool "Issue a diagnostic and abort()"
endchoice
config UCLIBC_HAS_WCHAR
bool "Wide Character Support"
default n
help
Answer Y to enable wide character support. This will make uClibc
much larger. It is also currently required for locale support.
Most people will answer N.
config UCLIBC_HAS_LOCALE
bool "Locale Support"
select UCLIBC_HAS_WCHAR
select UCLIBC_HAS_CTYPE_TABLES
default n
help
uClibc now has full ANSI/ISO C99 locale support (except for
wcsftime() and collating items in regex). Be aware that enabling
this option will make uClibc much larger.
Enabling UCLIBC_HAS_LOCALE with the default set of supported locales
(169 UTF-8 locales, and 144 locales for other codesets) will enlarge
uClibc by around 300k. You can reduce this size by building your own
custom set of locate data (see extra/locale/LOCALES for details).
uClibc's locale support is still under development. For example,
codesets using shift states are not currently supported. Support is
planned in the next iteration of locale support.
Answer Y to enable locale support. Most people will answer N.
choice
prompt "Locale data"
depends on UCLIBC_HAS_LOCALE
default UCLIBC_BUILD_ALL_LOCALE
config UCLIBC_BUILD_ALL_LOCALE
bool "All locales"
depends on UCLIBC_HAS_LOCALE
help
This builds all the locales that are available on your
host-box.
config UCLIBC_BUILD_MINIMAL_LOCALE
bool "Only selected locales"
depends on UCLIBC_HAS_LOCALE
help
If you do not need all locales that are available on your
host-box, then set this to 'Y'.
config UCLIBC_PREGENERATED_LOCALE_DATA
bool "Use Pre-generated Locale Data"
depends on UCLIBC_HAS_LOCALE
help
Use pre-built locale data.
Note that these pregenerated locales are sensitive to your
target architecture (endianess, bitcount).
Saying N here is highly recommended.
endchoice
config UCLIBC_BUILD_MINIMAL_LOCALES
string "locales to use"
depends on UCLIBC_BUILD_MINIMAL_LOCALE
default "en_US"
help
Space separated list of locales to use.
E.g.:
en_US en_GB de_AT
default:
en_US
config UCLIBC_DOWNLOAD_PREGENERATED_LOCALE_DATA
bool "Automagically Download the Pre-generated Locale Data (if necessary)"
depends on UCLIBC_PREGENERATED_LOCALE_DATA
default n
help
If you would like the build process to use 'wget' to automatically
download the pregenerated locale data, enable this option. Otherwise
you will need to obtain the locale data yourself from:
http://www.uclibc.org/downloads/uClibc-locale-*.tgz
and place the uClibc-locale-*.tgz tarball in the extra/locale/
directory.
Note that the use of pregenerated locale data is discouraged.
config UCLIBC_HAS_XLOCALE
bool "Extended Locale Support (experimental/incomplete)"
depends on UCLIBC_HAS_LOCALE
default n
help
Answer Y to enable extended locale support similar to that provided
by glibc. This is primarily intended to support libstd++
functionality.
However, it also allows thread-specific locale selection via
uselocale().
Most people will answer N.
config UCLIBC_HAS_HEXADECIMAL_FLOATS
bool "Support hexadecimal float notation"
depends on UCLIBC_HAS_CTYPE_TABLES
depends on UCLIBC_HAS_FLOATS
default n
help
Answer Y to enable support for hexadecimal float notation in the
(wchar and) char string to floating point conversion functions, as
well as support for the %a and %A conversion specifiers in the
*printf() and *scanf() functions.
Most people will answer N.
config UCLIBC_HAS_GLIBC_DIGIT_GROUPING
bool "Support glibc's \"'\" flag for allowing locale-specific digit grouping"
depends on UCLIBC_HAS_LOCALE
depends on UCLIBC_HAS_FLOATS
default n
help
Answer Y to enable support for glibc's \"'\" flag for allowing
locale-specific digit grouping in base 10 integer conversions and
appropriate floating point conversions in the *printf() and *scanf()
functions.
Most people will answer N.
config UCLIBC_HAS_SCANF_LENIENT_DIGIT_GROUPING
bool "Do not require digit grouping when the \"'\" flag is specified"
depends on UCLIBC_HAS_GLIBC_DIGIT_GROUPING
default y
help
Answer Y to make digit grouping optional when the \"'\" flag is
specified.
This is the standard glibc behavior. If the initial string of digits
exceeds the maximum group number, the input will be treated as a
normal non-grouped number.
Most people will answer N.
config UCLIBC_HAS_GLIBC_CUSTOM_PRINTF
bool "Support glibc's register_printf_function() (glibc-compat)"
depends on !USE_OLD_VFPRINTF
default n
help
Answer Y to support glibc's register_printf_function() to allow an
application to add its own printf conversion specifiers.
NOTE: Limits the number or registered specifiers to 10.
NOTE: Requires new conversion specifiers to be ASCII
characters (0-0x7f). This is to avoid problems with processing
format strings in locales with different multibyte conversions.
Most people will answer N.
config USE_OLD_VFPRINTF
bool "Use the old vfprintf implementation"
depends on !UCLIBC_HAS_WCHAR
default n
help
Set to true to use the old vfprintf instead of the new. This is
roughly C89 compliant with some extensions, and is much smaller.
However, it does not support wide chars, positional args, or glibc
custom printf specifiers.
Most people will answer N.
config UCLIBC_PRINTF_SCANF_POSITIONAL_ARGS
int "Maximum number of positional args. Either 0 or >= 9."
depends on !USE_OLD_VFPRINTF
default 9
help
Set the maximum number of positional args supported by the
printf/scanf functions. The Single Unix Specification Version 3
requires a minimum value of 9. Setting this to a value lower than
9 will disable positional arg support and cause the NL_ARGMAX macro
in limits.h to be #undef'd.
WARNING! The workspace to support positional args is currently
allocated on the stack. You probably don't want to set
this to too high a value.
Most people will answer 9.
config UCLIBC_HAS_SCANF_GLIBC_A_FLAG
bool "Support glibc's 'a' flag for scanf string conversions (not implemented)"
default n
help
NOTE!!! Currently Not Implemented!!! Just A Place Holder!! NOTE!!!
NOTE!!! Conflicts with an ANSI/ISO C99 scanf flag!! NOTE!!!
Answer Y to enable support for glibc's 'a' flag for the scanf string
conversions '%s', '%[', '%ls', '%l[', and '%S'. This is used to
auto-allocate sufficient memory to hold the data retrieved.
Most people will answer N.
choice
prompt "Stdio buffer size"
default UCLIBC_HAS_STDIO_BUFSIZ_4096
help
Please select a value for BUFSIZ. This will be used by the
stdio subsystem as the default buffer size for a file, and
affects fopen(), setvbuf(), etc.
NOTE: Setting this to 'none' will disable buffering completely.
However, BUFSIZ will still be defined in stdio.h as 256 because
many applications use this value.
config UCLIBC_HAS_STDIO_BUFSIZ_NONE
bool "none (WARNING - BUFSIZ will be 256 in stdio.h)"
depends on !UCLIBC_HAS_WCHAR
config UCLIBC_HAS_STDIO_BUFSIZ_256
bool "256 (minimum ANSI/ISO C99 value)"
config UCLIBC_HAS_STDIO_BUFSIZ_512
bool "512"
config UCLIBC_HAS_STDIO_BUFSIZ_1024
bool "1024"
config UCLIBC_HAS_STDIO_BUFSIZ_2048
bool "2048"
config UCLIBC_HAS_STDIO_BUFSIZ_4096
bool "4096"
config UCLIBC_HAS_STDIO_BUFSIZ_8192
bool "8192"
# If you add more choices, you will need to update uClibc_stdio.h.
endchoice
choice
prompt "Stdio builtin buffer size (uClibc-specific)"
depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
default UCLIBC_HAS_STDIO_BUILTIN_BUFFER_NONE
help
When a FILE is created with fopen(), an attempt is made to allocate
a BUFSIZ buffer for it. If the allocation fails, fopen() will still
succeed but the FILE will be unbuffered.
This option adds a small amount of space to each FILE to act as an
emergency buffer in the event of a buffer allocation failure.
Most people will answer None.
config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_NONE
bool "None"
config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_4
bool "4"
config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_8
bool "8"
# If you add more choices, you will need to update uClibc_stdio.h.
endchoice
config UCLIBC_HAS_STDIO_SHUTDOWN_ON_ABORT
bool "Attempt to shutdown stdio subsystem when abort() is called."
default n
help
ANSI/ISO C99 requires abort() to be asyn-signal-safe. So there was
a behavioral change made in SUSv3. Previously, abort() was required
to have the affect of fclose() on all open streams. The wording has
been changed to "may" from "shall".
Most people will answer N.
config UCLIBC_HAS_STDIO_GETC_MACRO
bool "Provide a macro version of getc()"
depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
default y
help
Provide a macro version of getc().
Most people will answer Y.
config UCLIBC_HAS_STDIO_PUTC_MACRO
bool "Provide a macro version of putc()"
depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
default y
help
Provide a macro version of putc().
Most people will answer Y.
config UCLIBC_HAS_STDIO_AUTO_RW_TRANSITION
bool "Support auto-r/w transition"
default y
help
Answer Y to enable the stdio subsystem to automaticly transition
between reading and writing. This relaxes the ANSI/ISO C99
requirement:
When a file is opened with update mode ('+' as the second or third
character in the list of mode argument values), both input and output
may be performed on the associated stream. However, output shall not
be directly followed by input without an intervening call to the
fflush function or to a file positioning function (fseek, fsetpos,
or rewind), and input shall not be directly followed by output without
an intervening call to a file positioning function, unless the input
operation encounters end�of�file.
Most people will answer Y.
config UCLIBC_HAS_FOPEN_LARGEFILE_MODE
bool "Support an fopen() 'F' flag for large file mode (uClibc-specific)"
depends on UCLIBC_HAS_LFS
default n
help
Answer Y to enable a uClibc-specific extension to allow passing an
additional 'F' flag in the mode string for fopen() to specify that
the file should be open()ed with the O_LARGEFILE flag set.
Most people will answer N.
config UCLIBC_HAS_FOPEN_EXCLUSIVE_MODE
bool "Support an fopen() 'x' flag for exclusive mode (glibc-compat)"
default n
help
Answer Y to support a glibc extension to allow passing
additional 'x' flag in the mode string for fopen() to specify that
the file should be open()ed with the O_EXCL flag set.
Most people will answer N.
config UCLIBC_HAS_GLIBC_CUSTOM_STREAMS
bool "Support fmemopen(), open_memstream(), and fopencookie() (glibc-compat)"
default n
help
Answer Y to support the glibc 'custom stream' extension functions
fmemopen(), open_memstream(), and fopencookie().
NOTE: There are some minor differences regarding seeking behavior.
Most people will answer N.
config UCLIBC_HAS_PRINTF_M_SPEC
bool "Support the '%m' specifier in printf format strings (glibc-compat)"
default n
help
Answer Y to support a glibc extension to interpret '%m' in printf
format strings as an instruction to output the error message string
(as generated by strerror) corresponding to the current value of
'errno'.
Most people will answer N.
config UCLIBC_HAS_ERRNO_MESSAGES
bool "Include the errno message text in the library"
default y
help
Answer Y if you want to include the errno message text in the
library. This adds about 3K to the library, but enables strerror()
to generate text other than 'Unknown error <number>'.
Most people will answer Y.
config UCLIBC_HAS_SYS_ERRLIST
bool "Support sys_errlist[] (obsolete-compat)"
depends on UCLIBC_HAS_ERRNO_MESSAGES
default n
help
Answer Y if you want to support the obsolete sys_errlist[].
This adds about 0.5k to the library, except for the mips
arch where it adds over 4K.
WARNING! In the future, support for sys_errlist[] may be unavailable
in at least some configurations. In fact, it may be removed
altogether.
Most people will answer N.
Application writers: use the strerror(3) function.
config UCLIBC_HAS_SIGNUM_MESSAGES
bool "Include the signum message text in the library"
default y
help
Answer Y if you want to include the signum message text in the
library. This adds about 0.5K to the library, but enables strsignal()
to generate text other than 'Unknown signal <number>'.
Most people will answer Y.
config UCLIBC_HAS_SYS_SIGLIST
bool "Support sys_siglist[] (bsd-compat)"
depends on UCLIBC_HAS_SIGNUM_MESSAGES
default n
help
Answer Y if you want to support sys_siglist[].
WARNING! In the future, support for sys_siglist[] may be unavailable
in at least some configurations. In fact, it may be removed
altogether.
Most people will answer N.
config UCLIBC_HAS_GETTEXT_AWARENESS
bool "Include gettext awareness"
depends on UCLIBC_HAS_LOCALE && UCLIBC_MJN3_ONLY
default n
help
NOTE!!! Not yet integrated with strerror and strsignal. NOTE!!!
Answer Y if you want to include weak stub gettext support and
make the *strerror*() and strsignal() functions gettext-aware.
Currently, to get functional gettext functionality you will need
to use gnu gettext.
Most people will answer N.
config UCLIBC_HAS_GNU_GETOPT
bool "Support gnu getopt"
default y
help
Answer Y if you want to include full gnu getopt() instead of a
(much smaller) SUSv3 compatible getopt().
Most people will answer Y.
config UCLIBC_HAS_STDIO_FUTEXES
bool "Use futexes for multithreaded I/O locking"
default n
depends on UCLIBC_HAS_THREADS_NATIVE
help
If you want to compile uClibc to use futexes for low-level
I/O locking, answer Y. Otherwise, answer N.
config UCLIBC_HAS_GETOPT_LONG
bool "Support getopt_long/getopt_long_only"
depends on !UCLIBC_HAS_GNU_GETOPT
default y
help
Answer Y if you want to include getopt_long[_only() used by many
apps, even busybox.
Most people will answer Y.
config UCLIBC_HAS_GNU_GETSUBOPT
bool "Support glibc getsubopt"
default y
help
Answer Y if you want to include glibc getsubopt() instead of a
smaller SUSv3 compatible getsubopt().
Most people will answer Y.
endmenu
menu "Big and Tall"
config UCLIBC_HAS_REGEX
bool "Regular Expression Support"
default y
help
POSIX regular expression code is really big -- 53k all by itself.
If you don't use regular expressions, turn this off and save space.
Of course, if you only statically link, leave this on, since it will
only be included in your apps if you use regular expressions.
config UCLIBC_HAS_REGEX_OLD
bool "Use the older (stable) regular expression code"
depends on UCLIBC_HAS_REGEX
default y
help
There are two versions of regex. The older (stable) version has
been in uClibc for quite a long time but hasn't seen too many
updates. It also has some known issues when dealing with uncommon
corner cases and multibyte/unicode strings. However, it is quite
a bit smaller than the newer version.
If the older version has worked for you and you don't need unicode
support, then stick with the old version (and say Y here).
Otherwise, you should use the new version (and say N here).
config UCLIBC_HAS_FNMATCH
bool "fnmatch Support"
default y
help
POSIX fnmatch.
config UCLIBC_HAS_FNMATCH_OLD
bool "Use the older (stable) fnmatch code"
depends on UCLIBC_HAS_FNMATCH
default y
help
There are two versions of fnmatch. The older (stable) version has
been in uClibc for quite a long time but hasn't seen too many
updates. It also has some known issues when dealing with uncommon
corner cases and multibyte/unicode strings. However, it is quite
a bit smaller than the newer version.
If the older version has worked for you and you don't need unicode
support, then stick with the old version (and say Y here).
Otherwise, you should use the new version (and say N here).
config UCLIBC_HAS_WORDEXP
bool "Support the wordexp() interface"
depends on UCLIBC_HAS_GLOB
default n
help
The SuSv3 wordexp() interface performs word expansions per the Shell
and Utilities volume of IEEE Std 1003.1-2001, Section 2.6. It is
intended for use by applications that want to implement all of the
standard Bourne shell expansions on input data.
This interface is rarely used, and very large. Unless you have a
pressing need for wordexp(), you should probably answer N.
config UCLIBC_HAS_NFTW
bool "Support the nftw() interface"
default n
help
The SuSv3 nftw() interface is used to recursively descend
directory paths while repeatedly calling a function.
This interface is rarely used, and adds around 4.5k. Unless you have
a pressing need for nftw(), you should probably answer N.
config UCLIBC_HAS_FTW
bool "Support the ftw() interface"
default n
depends on UCLIBC_SUSV4_LEGACY
help
The SuSv3 ftw() interface is used to recursively descend
directory paths while repeatedly calling a function.
This interface is rarely used, and adds around 4.5k. Unless you have
a pressing need for ftw(), you should probably answer N.
config UCLIBC_HAS_GLOB
bool "Support the glob() interface"
depends on UCLIBC_HAS_FNMATCH
default y
help
The glob interface is somewhat large (weighing in at about 2,5k). It
is used fairly often, but is an option since people wanting to go for
absolute minimum size may wish to omit it.
Most people will answer Y.
config UCLIBC_HAS_GNU_GLOB
bool "Support gnu glob() interface"
depends on UCLIBC_HAS_GLOB
default n
help
The gnu glob interface is somewhat larger (weighing in at about 4,2k)
than it's SuSv3 counterpart (and is out of date). It is an old copy
from glibc and does not support all the GNU specific options.
Answer Y if you want to include full gnu glob() instead of the smaller
SUSv3 compatible glob().
Most people will answer N.
endmenu
menu "Library Installation Options"
config SHARED_LIB_LOADER_PREFIX
string "Shared library loader path"
depends on HAVE_SHARED
default "$(RUNTIME_PREFIX)lib"
help
When using shared libraries, this path is the location where the
shared library will be invoked. This value will be compiled into
every binary compiled with uClibc.
For a typical target system this should be set to "/lib", such that
'make install' will install /lib/ld-uClibc.so.0.
BIG FAT WARNING:
If you do not have a shared library loader with the correct name
sitting in the directory this points to, your binaries will not
run.
config RUNTIME_PREFIX
string "uClibc runtime library directory"
default "/usr/$(TARGET_ARCH)-linux-uclibc/"
help
RUNTIME_PREFIX is the directory into which the uClibc runtime
libraries will be installed. The result will look something
like the following:
$(RUNTIME_PREFIX)/
lib/ <contains all runtime libraries>
usr/bin/ldd <the ldd utility program>
sbin/ldconfig <the ldconfig utility program>
This value is used by the 'make install' Makefile target. Since this
directory is compiled into the shared library loader, you will need to
recompile uClibc if you change this value...
For a typical target system this should be set to "/", such that
'make install' will install /lib/libuClibc-<VERSION>.so
config DEVEL_PREFIX
string "uClibc development environment directory"
default "/usr/$(TARGET_ARCH)-linux-uclibc/usr/"
help
DEVEL_PREFIX is the directory into which the uClibc development
environment will be installed. The result will look something
like the following:
$(DEVEL_PREFIX)/
lib/ <contains static libs>
include/ <Where all the header files go>
This value is used by the 'make install' Makefile target when
installing a uClibc development environment.
For a typical target system this should be set to "/usr", such that
'make install' will install /usr/include/<header files>.
config HARDWIRED_ABSPATH
bool "Hardwire absolute paths into linker scripts"
default y
help
This prepends absolute paths to the libraries mentioned in linker
scripts such as libc.so.
This is a build time optimization. It has no impact on dynamic
linking at runtime, which doesn't use linker scripts.
You must disable this to use uClibc with old non-sysroot toolchains,
such as the prebuilt binary cross compilers at:
http://uclibc.org/downloads/binaries
The amount of time saved by this optimization is actually too small to
measure. The linker just had to search the library path to find the
linker script, so the dentries are cache hot if it has to search the
same path again. But it's what glibc does, so we do it too.
endmenu
menu "Security options"
config UCLIBC_BUILD_PIE
bool "Build utilities as ET_DYN/PIE executables"
depends on HAVE_SHARED
depends on TARGET_arm || TARGET_frv || TARGET_i386 || TARGET_mips || TARGET_powerpc
select FORCE_SHAREABLE_TEXT_SEGMENTS
default n
help
If you answer Y here, ldd and iconv are built as ET_DYN/PIE
executables.
It requires gcc-3.4 and binutils-2.15 (for arm 2.16) or later.
More about ET_DYN/PIE binaries on <http://pax.grsecurity.net/> .
WARNING: This option also enables FORCE_SHAREABLE_TEXT_SEGMENTS, so
all libraries have to be built with -fPIC or -fpic, and all
assembler functions must be written as position independent
code (PIC).
config UCLIBC_HAS_ARC4RANDOM
bool "Include the arc4random() function"
default n
help
Answer Y to support the OpenBSD-like arc4random() function. This
function picks a random number between 0 and N, and will always return
something even if the random driver is dead. If urandom fails then
gettimeofday(2) will be used as the random seed. This function is
designed to be more dependable than invoking /dev/urandom directly.
OpenSSL and OpenNTPD currently support this function.
Most people will answer N.
config HAVE_NO_SSP
bool
default n
config UCLIBC_HAS_SSP
bool "Support for GCC stack smashing protector"
depends on !HAVE_NO_SSP
default n
help
Add code to support GCC's -fstack-protector[-all] option to uClibc.
This requires GCC 4.1 or newer. GCC does not have to provide libssp,
the needed functions are added to ldso/libc instead.
GCC's stack protector is a reimplementation of IBM's propolice.
See http://www.trl.ibm.com/projects/security/ssp/ and
http://www.linuxfromscratch.org/hints/downloads/files/ssp.txt
for details.
Note that NOEXECSTACK on a kernel with address space randomization
is generally sufficient to prevent most buffer overflow exploits
without increasing code size. This option essentially adds debugging
code to catch them.
Most people will answer N.
config UCLIBC_HAS_SSP_COMPAT
bool "Support for gcc-3.x propolice smashing stack protector"
depends on UCLIBC_HAS_SSP
default n
help
Add gcc-3.x propolice smashing stack protector to the library.
This requires a patched version of GCC, supporting the
-fstack-protector[-all] options, with the __guard and
__stack_smash_handler functions removed from libgcc.
These functions are added to ldso/libc instead.
More information at:
<http://www.research.ibm.com/trl/projects/security/ssp/>
Most people will answer N.
config SSP_QUICK_CANARY
bool "Use simple guard values without accessing /dev/urandom"
depends on UCLIBC_HAS_SSP
default n
help
Use gettimeofday(2) to define the __guard without accessing
/dev/urandom.
WARNING: This makes smashing stack protector vulnerable to timing
attacks.
Most people will answer N.
choice
prompt "Propolice protection blocking signal"
depends on UCLIBC_HAS_SSP
default PROPOLICE_BLOCK_ABRT if ! DODEBUG
default PROPOLICE_BLOCK_SEGV if DODEBUG
help
"abort" use SIGABRT to block offending programs.
This is the default implementation.
"segfault" use SIGSEGV to block offending programs.
Use this for debugging.
If unsure, answer "abort".
config PROPOLICE_BLOCK_ABRT
bool "abort"
config PROPOLICE_BLOCK_SEGV
bool "segfault"
endchoice
config UCLIBC_BUILD_SSP
bool "Build uClibc with -fstack-protector"
depends on UCLIBC_HAS_SSP
default n
help
Build all uClibc libraries and executables with -fstack-protector,
adding extra stack overflow checking to most uClibc functions.
config UCLIBC_BUILD_RELRO
bool "Build uClibc with linker option -z RELRO"
depends on HAVE_SHARED
default y
help
Build all libraries and executables with "ld -z relro".
This tells the linker to mark chunks of an executable or shared
library read-only after applying dynamic relocations. (This comes
up when a global const variable is initialized to the address of a
function or the value of another global variable.)
This is a fairly obscure option the ld man page doesn't even bother
to document properly. It's a security paranoia issue that's more
likely to consume memory (by allocating an extra page) rather than
save it.
This is explained in more depth at
http://www.airs.com/blog/archives/189
Nobody is likely to care whether you say Y or N here.
config UCLIBC_BUILD_NOW
bool "Build uClibc with linker option -z NOW"
depends on HAVE_SHARED
default n
help
Build all libraries and executables with "ld -z now".
This tells the linker to resolve all symbols when the library is
first loaded, rather than when each function is first called. This
increases start-up latency by a few microseconds and may do
unnecessary work (resolving symbols that are never used), but the
realtime people like it for making microbenchmark timings slightly
more predictable and in some cases it can be slightly faster due to
CPU cache behavior (not having to fault the linker back in to do
lazy symbol resolution).
Most people can't tell the difference between selecting Y or N here.
config UCLIBC_BUILD_NOEXECSTACK
bool "Build uClibc with noexecstack marking"
default y
help
Mark all assembler files as noexecstack, which will mark uClibc
as not requiring an executable stack. (This doesn't prevent other
files you link against from claiming to need an executable stack, it
just won't cause uClibc to request it unnecessarily.)
This is a security thing to make buffer overflows harder to exploit.
By itself, it's kind of useless, as Linus Torvalds explained in 1998:
http://old.lwn.net/1998/0806/a/linus-noexec.html
It only actually provides any security when combined with address
space randomization, explained here: http://lwn.net/Articles/121845/
Address space randomization is on by default in current linux
kernels (although it can be disabled using the option
CONFIG_COMPAT_BRK).
You should probably say Y.
endmenu
menu "uClibc development/debugging options"
config CROSS_COMPILER_PREFIX
string "Cross-compiling toolchain prefix"
default ""
help
The prefix used to execute your cross-compiling toolchain. For
example, if you run 'arm-linux-uclibc-gcc' to compile something,
then enter 'arm-linux-uclibc-' here.
config UCLIBC_EXTRA_CFLAGS
string "Enter any extra CFLAGS to use to build uClibc"
default ""
help
Add any additional CFLAGS to be used to build uClibc.
config DODEBUG
bool "Build uClibc with debugging symbols"
default n
select EXTRA_WARNINGS
help
Say Y here if you wish to compile uClibc with debugging symbols.
This will allow you to use a debugger to examine uClibc internals
while applications are running. This increases the size of the
library considerably and should only be used when doing development.
If you are doing development and want to debug uClibc, answer Y.
Otherwise, answer N.
config DODEBUG_PT
bool "Build pthread with debugging output"
depends on UCLIBC_HAS_THREADS && LINUXTHREADS_OLD
default n
help
Enable debug output in libpthread. This is only useful when doing
development in libpthread itself.
Otherwise, answer N.
config DOSTRIP
bool "Strip libraries and executables"
default y
depends on !DODEBUG
help
Say Y here if you do wish to strip all uClibc libraries and
executables. No stripping increases the size of the binaries
considerably, but makes it possible to debug uClibc libraries.
Most people will answer Y.
config DOASSERTS
bool "Build uClibc with run-time assertion testing"
default n
help
Say Y here to include runtime assertion tests.
This enables runtime assertion testing in some code, which can
increase the size of the library and incur runtime overhead.
If you say N, then this testing will be disabled.
config SUPPORT_LD_DEBUG
bool "Build the shared library loader with debugging support"
depends on HAVE_SHARED
default n
help
Answer Y here to enable all the extra code needed to debug the uClibc
native shared library loader. The level of debugging noise that is
generated depends on the LD_DEBUG environment variable... Just set
LD_DEBUG to something like: 'LD_DEBUG=token1,token2,.. prog' to
debug your application. Diagnostic messages will then be printed to
the stderr.
For now these debugging tokens are available:
detail provide more information for some options
move display copy processing
symbols display symbol table processing
reloc display relocation processing; detail shows the
relocation patch
nofixups never fixes up jump relocations
bindings displays the resolve processing (function calls);
detail shows the relocation patch
all Enable everything!
The additional environment variable:
LD_DEBUG_OUTPUT=file
redirects the diagnostics to an output file created using
the specified name and the process id as a suffix.
An excellent start is simply:
$ LD_DEBUG=binding,move,symbols,reloc,detail ./appname
or to log everything to a file named 'logfile', try this
$ LD_DEBUG=all LD_DEBUG_OUTPUT=logfile ./appname
If you are doing development and want to debug uClibc's shared library
loader, answer Y. Mere mortals answer N.
config SUPPORT_LD_DEBUG_EARLY
bool "Build the shared library loader with early debugging support"
depends on HAVE_SHARED
default n
help
Answer Y here to if you find the uClibc shared library loader is
crashing or otherwise not working very early on. This is typical
only when starting a new port when you haven't figured out how to
properly get the values for argc, argv, environ, etc. This method
allows a degree of visibility into the very early shared library
loader initialization process. If you are doing development and want
to debug the uClibc shared library loader early initialization,
answer Y. Mere mortals answer N.
config UCLIBC_MALLOC_DEBUGGING
bool "Build malloc with debugging support"
depends on MALLOC || MALLOC_STANDARD
default n
help
Answer Y here to compile extra debugging support code into malloc.
Malloc debugging output may then be enabled at runtime using the
MALLOC_DEBUG environment variable.
The value of MALLOC_DEBUG should be an integer, which is interpreted
as a bitmask with the following bits:
1 - do extra consistency checking
2 - output messages for malloc/free calls and OS
allocation calls
4 - output messages for the `MMB' layer
8 - output messages for internal malloc heap manipulation
calls
Because this increases the size of malloc appreciably (due to strings
etc), you should say N unless you need to debug a malloc problem.
config WARNINGS
string "Compiler Warnings"
default "-Wall"
help
Set this to the set of gcc warnings you wish to see while compiling.
config EXTRA_WARNINGS
bool "Enable extra annoying warnings"
default n
help
If you wish to build with extra warnings enabled, say Y here.
config DOMULTI
bool "Compile all sources at once into an object"
default n
help
Set this to compile all sources at once into an object (IMA).
This mode of compilation uses alot of memory but may produce
smaller binaries.
Note that you need a very recent GCC for this to work, like
gcc >= 4.3 plus eventually some patches.
If unsure, keep the default of N.
config UCLIBC_MJN3_ONLY
bool "Manuel's hidden warnings"
default n
help
Answer Y here to see all Manuel's personal notes, warnings, and todos.
Most people will answer N.
endmenu
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