2 # For a description of the syntax of this configuration file,
3 # see extra/config/Kconfig-language.txt
6 mainmenu "uClibc C Library Configuration"
8 config DESIRED_TARGET_ARCH
13 prompt "Target Architecture"
14 default TARGET_alpha if DESIRED_TARGET_ARCH = "alpha"
15 default TARGET_arm if DESIRED_TARGET_ARCH = "arm"
16 default TARGET_avr32 if DESIRED_TARGET_ARCH = "avr32"
17 default TARGET_bfin if DESIRED_TARGET_ARCH = "bfin"
18 default TARGET_cris if DESIRED_TARGET_ARCH = "cris"
19 default TARGET_e1 if DESIRED_TARGET_ARCH = "e1"
20 default TARGET_frv if DESIRED_TARGET_ARCH = "frv"
21 default TARGET_h8300 if DESIRED_TARGET_ARCH = "h8300"
22 default TARGET_hppa if DESIRED_TARGET_ARCH = "hppa"
23 default TARGET_i386 if DESIRED_TARGET_ARCH = "i386"
24 default TARGET_i960 if DESIRED_TARGET_ARCH = "i960"
25 default TARGET_ia64 if DESIRED_TARGET_ARCH = "ia64"
26 default TARGET_m68k if DESIRED_TARGET_ARCH = "m68k"
27 default TARGET_microblaze if DESIRED_TARGET_ARCH = "microblaze"
28 default TARGET_mips if DESIRED_TARGET_ARCH = "mips"
29 default TARGET_nios if DESIRED_TARGET_ARCH = "nios"
30 default TARGET_nios2 if DESIRED_TARGET_ARCH = "nios2"
31 default TARGET_powerpc if DESIRED_TARGET_ARCH = "powerpc"
32 default TARGET_sh if DESIRED_TARGET_ARCH = "sh"
33 default TARGET_sh64 if DESIRED_TARGET_ARCH = "sh64"
34 default TARGET_sparc if DESIRED_TARGET_ARCH = "sparc"
35 default TARGET_v850 if DESIRED_TARGET_ARCH = "v850"
36 default TARGET_vax if DESIRED_TARGET_ARCH = "vax"
37 default TARGET_x86_64 if DESIRED_TARGET_ARCH = "x86_64"
38 default TARGET_xtensa if DESIRED_TARGET_ARCH = "xtensa"
40 The architecture of your target.
84 config TARGET_microblaze
123 menu "Target Architecture Features and Options"
126 source "extra/Configs/Config.alpha"
130 source "extra/Configs/Config.arm"
134 source "extra/Configs/Config.avr32"
138 source "extra/Configs/Config.bfin"
142 source "extra/Configs/Config.cris"
146 source "extra/Configs/Config.e1"
150 source "extra/Configs/Config.frv"
154 source "extra/Configs/Config.h8300"
158 source "extra/Configs/Config.hppa"
162 source "extra/Configs/Config.i386"
166 source "extra/Configs/Config.i960"
170 source "extra/Configs/Config.ia64"
174 source "extra/Configs/Config.m68k"
178 source "extra/Configs/Config.nios"
182 source "extra/Configs/Config.nios2"
186 source "extra/Configs/Config.microblaze"
190 source "extra/Configs/Config.mips"
194 source "extra/Configs/Config.powerpc"
198 source "extra/Configs/Config.sh"
202 source "extra/Configs/Config.sh64"
206 source "extra/Configs/Config.sparc"
210 source "extra/Configs/Config.v850"
214 source "extra/Configs/Config.vax"
218 source "extra/Configs/Config.x86_64"
222 source "extra/Configs/Config.xtensa"
226 source "extra/Configs/Config.c6x"
229 config TARGET_SUBARCH
231 default "e500" if CONFIG_E500
232 default "classic" if CONFIG_CLASSIC
233 default "sh4" if CONFIG_SH4
234 default "" if CONFIG_GENERIC_386 || CONFIG_386
235 default "i486" if CONFIG_486
236 default "i586" if CONFIG_586 || CONFIG_586MMX
237 default "i686" if TARGET_ARCH = "i386"
240 source "extra/Configs/Config.in.arch"
244 menu "General Library Settings"
250 bool "Generate only Position Independent Code (PIC)"
252 depends on !HAVE_NO_PIC
254 If you wish to build all of uClibc as PIC objects, then answer Y here.
255 If you are unsure, then you should answer N.
257 config ARCH_HAS_NO_SHARED
260 config ARCH_HAS_NO_LDSO
262 select ARCH_HAS_NO_SHARED
265 bool "Enable shared libraries"
266 depends on !ARCH_HAS_NO_SHARED
269 If you wish to build uClibc with support for shared libraries then
270 answer Y here. If you only want to build uClibc as a static library,
273 config FORCE_SHAREABLE_TEXT_SEGMENTS
274 bool "Only load shared libraries which can share their text segment"
275 depends on HAVE_SHARED
278 If you answer Y here, the uClibc native shared library loader will
279 only load shared libraries, which do not need to modify any
280 non-writable segments. These libraries haven't set the DT_TEXTREL
281 tag in the dynamic section (==> objdump).
282 All your libraries must be compiled with -fPIC or -fpic, and all
283 assembler function must be written as position independent code (PIC).
284 Enabling this option will make uClibc's shared library loader a
285 little bit smaller and guarantee that no memory will be wasted by
286 badly coded shared libraries.
288 config LDSO_LDD_SUPPORT
289 bool "Native 'ldd' support"
290 depends on HAVE_SHARED
293 Enable all the code needed to support traditional ldd,
294 which executes the shared library loader to resolve all dependencies
295 and then provide a list of shared libraries that are required for an
296 application to function. Disabling this option will make uClibc's
297 shared library loader a little bit smaller.
298 Most people will answer Y.
300 config LDSO_CACHE_SUPPORT
301 bool "Enable library loader cache (ld.so.conf)"
302 depends on HAVE_SHARED
305 Enable this to make use of /etc/ld.so.conf, the shared library loader
306 cache configuration file to support for non-standard library paths.
307 After updating this file, it is necessary to run 'ldconfig' to update
308 the /etc/ld.so.cache shared library loader cache file.
310 config LDSO_PRELOAD_ENV_SUPPORT
311 bool "Enable library loader LD_PRELOAD environment"
312 depends on HAVE_SHARED
315 Enable this to make use of LD_PRELOAD environment variable.
316 A whitespace-separated list of additional, user-specified, ELF shared
317 libraries to be loaded before all others. This can be used to
318 selectively override functions in other shared libraries. For
319 set-user-ID/set-group-ID ELF binaries, only libraries in the standard
320 search directories that are also set-user-ID will be loaded.
322 config LDSO_PRELOAD_FILE_SUPPORT
323 bool "Enable library loader preload file (ld.so.preload)"
324 depends on HAVE_SHARED
326 Enable this to make use of /etc/ld.so.preload. This file contains a
327 whitespace separated list of shared libraries to be loaded before
330 config LDSO_BASE_FILENAME
331 string "Shared library loader naming prefix"
332 depends on HAVE_SHARED && (LDSO_CACHE_SUPPORT || LDSO_PRELOAD_FILE_SUPPORT)
335 If you wish to support both uClibc and glibc on the same system, it
336 is necessary to set this to something other than "ld.so" to avoid
337 conflicts with glibc, which also uses "ld.so". This prevents both
338 libraries from using the same /etc/ld.so.* files. If you wish to
339 support both uClibc and glibc on the same system then you should set
340 this to "ld-uClibc.so".
342 Most people will leave this set to the default of "ld.so".
344 WARNING: Changing the default prefix could cause problems with
347 config LDSO_STANDALONE_SUPPORT
348 bool "Dynamic linker stand-alone mode support"
349 depends on HAVE_SHARED
351 The dynamic linker can be run either indirectly through running some
352 dynamically linked program or library (in which case no command line
353 options to the dynamic linker can be passed and, in the ELF case, the
354 dynamic linker which is stored in the .interp section of the program
355 is executed) or directly by running:
357 /lib/ld-uClibc.so.* [OPTIONS] [PROGRAM [ARGUMENTS]]
359 Stand-alone execution is a prerequisite for adding prelink
360 capabilities to uClibc dynamic linker, as well useful for testing an
361 updated version of the dynamic linker without breaking the system.
363 config LDSO_PRELINK_SUPPORT
364 bool "Dynamic linker prelink support"
365 depends on HAVE_SHARED
366 select LDSO_STANDALONE_SUPPORT
368 The dynamic linker can be used in stand-alone mode by the prelink tool
369 for prelinking ELF shared libraries and binaries to speed up startup
370 time. It also is able to load and handle prelinked libraries and
373 config UCLIBC_STATIC_LDCONFIG
374 bool "Link ldconfig statically"
375 depends on HAVE_SHARED
378 Enable this option to statically link the ldconfig binary.
380 Making ldconfig static can be beneficial if you have a library
381 problem and need to use ldconfig to recover. Sometimes it is
382 preferable to instead keep the size of the system down, in which
383 case you should disable this option.
386 bool "Enable ELF RUNPATH tag support"
387 depends on HAVE_SHARED
388 default y if LDSO_CACHE_SUPPORT
390 ELF's may have dynamic RPATH/RUNPATH tags. These tags list paths
391 which extend the library search paths. They are really only useful
392 if a package installs libraries in non standard locations and
393 ld.so.conf support is disabled.
395 Usage of RUNPATH tags is not too common, so disabling this feature
396 should be safe for most people.
398 config LDSO_SAFE_RUNPATH
399 bool "Allow only RUNPATH beginning with /"
400 depends on LDSO_RUNPATH
403 Allow only absolute path in RPATH/RUNPATH.
405 config LDSO_SEARCH_INTERP_PATH
406 bool "Add ldso path to lib search path"
407 depends on HAVE_SHARED
410 The ldso is told where it is being executed from and can use that
411 path to find related core libraries. This is useful by default,
412 but can be annoying in a mixed development environment.
414 i.e. if the ldso is run from /foo/boo/ldso.so, it will start its
415 library search with /foo/boo/
417 If unsure, simply say Y here.
419 config LDSO_LD_LIBRARY_PATH
420 bool "Add LD_LIBRARY_PATH to lib search path"
421 depends on HAVE_SHARED
424 On hardened system it could be useful to disable the use of
425 LD_LIBRARY_PATH environment variable (a colon-separated list of
426 directories in which to search for ELF libraries at execution-time).
428 If unsure, simply say Y here.
430 config LDSO_NO_CLEANUP
431 bool "Disable automatic unloading of dynamically loaded shared objects"
432 depends on HAVE_SHARED
435 If you need complete allocation traces when debugging memory leaks
436 using Valgrind in a process that dynamically loads shared objects,
437 then answer Y here. Unlike glibc, uClibc unloads all dynamically
438 loaded shared objects when a process exits, which prevents Valgrind
439 from correctly resolving the symbols from the unloaded shared objects.
440 Unless you know you need this, you should answer N.
442 config UCLIBC_CTOR_DTOR
443 bool "Support global constructors and destructors"
446 If you wish to build uClibc with support for global constructor
447 (ctor) and global destructor (dtor) support, then answer Y here.
448 When ctor/dtor support is enabled, binaries linked with uClibc must
449 also be linked with crtbegin.o and crtend.o which are provided by gcc
450 (the "*startfile:" and "*endfile:" settings in your gcc specs file
451 may need to be adjusted to include these files). This support will
452 also add a small amount of additional size to each binary compiled vs
453 uClibc. If you will be using uClibc with C++, or if you need the gcc
454 __attribute__((constructor)) and __attribute__((destructor)) to work,
455 then you definitely want to answer Y here. If you don't need ctors
456 or dtors and want your binaries to be as small as possible, then
459 config LDSO_GNU_HASH_SUPPORT
460 bool "Enable GNU hash style support"
461 depends on HAVE_SHARED
463 Newest binutils support a new hash style named GNU-hash. The dynamic
464 linker will use the new GNU-hash section (.gnu.hash) for symbol lookup
465 if present into the ELF binaries, otherwise it will use the old SysV
466 hash style (.hash). This ensures that it is completely backward
468 Further, being the hash table implementation self-contained into each
469 executable and shared libraries, objects with mixed hash style can
470 peacefully coexist in the same process.
472 If you want to use this new feature, answer Y
475 prompt "Thread support"
476 #default UCLIBC_HAS_THREADS_NATIVE if (TARGET_alpha || TARGET_arm || TARGET_i386 || TARGET_mips || TARGET_powerpc || TARGET_sh || TARGET_sh64)
477 default HAS_NO_THREADS
479 If you want to compile uClibc with pthread support, then answer Y.
480 This will increase the size of uClibc by adding a bunch of locking
481 to critical data structures, and adding extra code to ensure that
482 functions are properly reentrant.
484 config HAS_NO_THREADS
487 Disable thread support.
489 config LINUXTHREADS_OLD
490 bool "older (stable) version of linuxthreads"
491 # linuxthreads and linuxthreads.old need nanosleep()
492 select UCLIBC_HAS_REALTIME
494 There are two versions of linuxthreads. The older (stable) version
495 has been in uClibc for quite a long time but hasn't seen too many
496 updates other than bugfixes.
499 config LINUXTHREADS_NEW
500 bool "slightly newer version of linuxthreads"
502 The new version has not been tested much, and lacks ports for arches
503 which glibc does not support (like bfin/frv/etc...), but is based on
504 the latest code from glibc, so it may be the only choice for the
505 newer ports (like alpha/amd64/64bit arches and hppa).
507 config UCLIBC_HAS_THREADS_NATIVE
508 bool "Native POSIX Threading (NPTL)"
509 select UCLIBC_HAS_TLS
510 select UCLIBC_HAS_STDIO_FUTEXES
511 select UCLIBC_HAS_REALTIME
512 # i386 has no lowlevellock support (yet) as opposed to i486 onward
513 depends on !CONFIG_386
515 If you want to compile uClibc with NPTL support, then answer Y.
517 IMPORTANT NOTE! NPTL requires a Linux 2.6 kernel, binutils
518 at least version 2.16 and GCC with at least version 4.1.0. NPTL
519 will not work with older versions of any above sources. If you
520 ignore any of these guidelines, you do so at your own risk. Do
521 not ask for help on any of the development mailing lists.
523 !!!! WARNING !!!! BIG FAT WARNING !!!! REALLY BIG FAT WARNING !!!!
525 This is experimental code and at times it may not even build and
526 even if it does it might decide to do random damage. This code is
527 potentially hazardous to your health and sanity. It will remain
528 that way until further notice at which point this notice will
529 disappear. Thank you for your support and for not smoking.
533 config UCLIBC_HAS_THREADS
534 def_bool y if !HAS_NO_THREADS
536 config UCLIBC_HAS_TLS
537 bool "Thread-Local Storage"
538 depends on UCLIBC_HAS_THREADS_NATIVE
540 If you want to enable TLS support then answer Y.
541 This is fast an efficient way to store per-thread local data
542 which is not on stack. It needs __thread support enabled in
545 config PTHREADS_DEBUG_SUPPORT
546 bool "Build pthreads debugging support"
547 depends on UCLIBC_HAS_THREADS
549 Say Y here if you wish to be able to debug applications that use
550 uClibc's pthreads library. By enabling this option, a library
551 named libthread_db will be built. This library will be dlopen()'d
552 by gdb and will allow gdb to debug the threads in your application.
554 IMPORTANT NOTE! Because gdb must dlopen() the libthread_db library,
555 you must compile gdb with uClibc in order for pthread debugging to
558 If you are doing development and want to debug applications using
559 uClibc's pthread library, answer Y. Otherwise, answer N.
562 config UCLIBC_HAS_SYSLOG
563 bool "Syslog support"
565 depends on UCLIBC_HAS_NETWORK_SUPPORT
566 select UCLIBC_HAS_SOCKET
568 Support sending messages to the system logger.
569 This requires socket-support.
571 config UCLIBC_HAS_LFS
572 bool "Large File Support"
575 If you wish to build uClibc with support for accessing large files
576 (i.e. files greater then 2 GiB) then answer Y. Do not enable this
577 if you are using an older Linux kernel (2.0.x) that lacks large file
578 support. Enabling this option will increase the size of uClibc.
581 prompt "Malloc Implementation"
582 default MALLOC if ! ARCH_USE_MMU
583 default MALLOC_STANDARD if ARCH_USE_MMU
588 "malloc" use mmap for all allocations and so works very well on
589 MMU-less systems that do not support the brk() system call. It is
590 pretty smart about reusing already allocated memory, and minimizing
592 This is the default for uClinux MMU-less systems.
597 "malloc-simple" is trivially simple and slow as molasses. It
598 was written from scratch for uClibc, and is the simplest possible
599 (and therefore smallest) malloc implementation.
601 This uses only the mmap() system call to allocate and free memory,
602 and does not use the brk() system call at all, making it a fine
603 choice for MMU-less systems with very limited memory. It's 100%
604 standards compliant, thread safe, very small, and releases freed
605 memory back to the OS immediately rather than keeping it in the
606 process's heap for reallocation. It is also VERY SLOW.
608 config MALLOC_STANDARD
609 bool "malloc-standard"
610 depends on ARCH_USE_MMU
612 "malloc-standard" is derived from the public domain dlmalloc
613 implementation by Doug Lea. It is quite fast, and is pretty smart
614 about reusing already allocated memory, and minimizing memory
615 wastage. This uses brk() for small allocations, while using mmap()
616 for larger allocations. This is the default malloc implementation
619 If unsure, answer "malloc-standard".
623 config MALLOC_GLIBC_COMPAT
624 bool "Malloc returns live pointer for malloc(0)"
626 The behavior of malloc(0) is listed as implementation-defined by
627 SuSv3. Glibc returns a valid pointer to something, while uClibc
628 normally returns NULL. I personally feel glibc's behavior is
629 not particularly safe, and allows buggy applications to hide very
632 When this option is enabled, uClibc will act just like glibc, and
633 return a live pointer when someone calls malloc(0). This pointer
634 provides a malloc'ed area with a size of 1 byte. This feature is
635 mostly useful when dealing with applications using autoconf's broken
636 AC_FUNC_MALLOC macro (which redefines malloc as rpl_malloc if it
637 does not detect glibc style returning-a-valid-pointer-for-malloc(0)
638 behavior). Most people can safely answer N.
640 config UCLIBC_DYNAMIC_ATEXIT
641 bool "Dynamic atexit() Support"
644 When this option is enabled, uClibc will support an infinite number,
645 of atexit() and on_exit() functions, limited only by your available
646 memory. This can be important when uClibc is used with C++, since
647 global destructors are implemented via atexit(), and it is quite
648 possible to exceed the default number when this option is disabled.
649 Enabling this option adds a few bytes, and more significantly makes
650 atexit and on_exit depend on malloc, which can be bad when compiling
653 Unless you use uClibc with C++, you should probably answer N.
656 bool "Old (visible) atexit Support"
658 Enable this option if you want to update from 0.9.28 to git/0.9.29,
659 else you will be missing atexit() until you rebuild all apps.
661 config UCLIBC_SUSV3_LEGACY
662 bool "Enable SuSv3 LEGACY functions"
668 Enable this option if you want to have SuSv3 LEGACY functions
669 in the library, else they are replaced by SuSv3 proposed macros.
670 Currently applies to:
672 bcmp, bcopy, bzero, index, rindex, ftime,
673 bsd_signal, (ecvt), (fcvt), gcvt, (getcontext),
674 (getwd), (makecontext),
675 mktemp, (pthread_attr_getstackaddr), (pthread_attr_setstackaddr),
676 scalb, (setcontext), (swapcontext), ualarm, usleep,
679 WARNING! ABI incompatibility.
681 config UCLIBC_SUSV3_LEGACY_MACROS
682 bool "Enable SuSv3 LEGACY macros"
684 Enable this option if you want to have SuSv3 LEGACY macros.
685 Currently applies to bcopy/bzero/bcmp/index/rindex et al.
686 WARNING! ABI incompatibility.
688 config UCLIBC_SUSV4_LEGACY
689 bool "Enable SuSv4 LEGACY or obsolescent functions"
691 Enable this option if you want to have SuSv4 LEGACY functions
692 and macros in the library.
693 Currently applies to:
696 _longjmp, _setjmp, _tolower, _toupper, ftw, getitimer,
697 gettimeofday, isascii, pthread_getconcurrency,
698 pthread_setconcurrency, setitimer, setpgrp, sighold,
699 sigignore, sigpause, sigrelse, sigset, siginterrupt,
700 tempnam, toascii, ulimit.
703 asctime, asctime_r, ctime, ctime_r, gets, rand_r,
706 WARNING! ABI incompatibility.
708 config UCLIBC_STRICT_HEADERS
709 bool "Hide structures and constants for unsupported features"
711 Hide structures and constants in headers that should not be used,
712 because the respective feature is disabled.
714 WARNING! enabling this option requires to patch many faulty apps,
715 since they make (wrongly) use of these structures/constants,
716 although the feature was disabled.
718 config UCLIBC_HAS_STUBS
719 bool "Provide stubs for unavailable functionality"
721 With this option uClibc provides non-functional stubs for
722 functions which are impossible to implement on the target
723 architecture. Otherwise, such functions are simply omitted.
725 config UCLIBC_HAS_SHADOW
726 bool "Shadow Password Support"
729 Answer N if you do not need shadow password support.
730 Most people will answer Y.
732 config UCLIBC_HAS_PROGRAM_INVOCATION_NAME
733 bool "Support for program_invocation_name"
735 Support for the GNU-specific program_invocation_name and
736 program_invocation_short_name strings. Some GNU packages
737 (like tar and coreutils) utilize these for extra useful
738 output, but in general are not required.
740 At startup, these external strings are automatically set
741 up based on the value of ARGV[0].
743 If unsure, just answer N.
745 config UCLIBC_HAS___PROGNAME
746 bool "Support for __progname"
748 depends on UCLIBC_HAS_PROGRAM_INVOCATION_NAME
750 Some packages (like openssh) like to peek into internal libc
751 symbols to make their output a bit more user friendly.
753 At startup, __progname is automatically set up based on the
756 If unsure, just answer N.
758 config UCLIBC_HAS_PTY
759 bool "Support for pseudo-terminals"
762 This enables support for pseudo-terminals (see man 4 pts
765 If unsure, just answer Y.
768 bool "Assume that /dev/pts is a devpts or devfs file system"
770 depends on UCLIBC_HAS_PTY
772 Enable this if /dev/pts is on a devpts or devfs filesystem. Both
773 these filesystems automatically manage permissions on the /dev/pts
774 devices. You may need to mount your devpts or devfs filesystem on
775 /dev/pts for this to work.
777 Most people should answer Y.
779 config UNIX98PTY_ONLY
780 bool "Support only Unix 98 PTYs"
782 depends on UCLIBC_HAS_PTY
784 If you want to support only Unix 98 PTYs enable this. Some older
785 applications may need this disabled and will thus use legacy BSD
786 style PTY handling which is more complex and also bigger than
787 Unix 98 PTY handling.
789 For most current programs, you can generally answer Y.
792 config UCLIBC_HAS_GETPT
793 bool "Support getpt() (glibc-compat)"
794 depends on UCLIBC_HAS_PTY
796 Some packages may need getpt().
797 All of those are non-standard and can be considered
798 GNU/libc compatibility.
799 Either use posix_openpt() or just open /dev/ptmx yourself.
801 If unsure, just say N.
805 # Have to use __libc_ptyname{1,2}[] and related bloat
806 config UCLIBC_HAS_GETPT
810 config UCLIBC_HAS_LIBUTIL
811 bool "Provide libutil library and functions"
812 depends on UCLIBC_HAS_PTY
814 Provide a libutil library.
815 This non-standard conforming library provides the following
818 forkpty(): combines openpty(), fork(2), and login_tty() to
819 create a new process operating in a pseudo-terminal.
820 login(): write utmp and wtmp entries
821 login_tty(): prepares for a login on the tty fd by creating a
822 new session, making fd the controlling terminal for
823 the calling process, setting fd to be the standard
824 input, output, and error streams of the current
825 process, and closing fd.
826 logout(): write utmp and wtmp entries
827 logwtmp(): constructs a utmp structure and calls updwtmp() to
828 append the structure to the utmp file.
829 openpty(): finds an available pseudo-terminal and returns
830 file descriptors for the master and slave
832 This library adds about 3k-4k to your system.
834 config UCLIBC_HAS_TM_EXTENSIONS
835 bool "Support 'struct tm' timezone extension fields"
838 Enabling this option adds fields to 'struct tm' in time.h for
839 tracking the number of seconds east of UTC, and an abbreviation for
840 the current timezone. These fields are not specified by the SuSv3
841 standard, but they are commonly used in both GNU and BSD application
844 To strictly follow the SuSv3 standard, leave this disabled.
845 Most people will probably want to answer Y.
847 config UCLIBC_HAS_TZ_CACHING
848 bool "Enable caching of the last valid timezone 'TZ' string"
851 Answer Y to enable caching of the last valid 'TZ' string describing
852 the timezone setting. This allows a quick string compare to avoid
853 repeated parsing of unchanged 'TZ' strings when tzset() is called.
855 Most people will answer Y.
857 config UCLIBC_HAS_TZ_FILE
858 bool "Enable '/etc/TZ' file support to set a default timezone (uClibc-specific)"
861 Answer Y to enable the setting of a default timezone for uClibc.
863 Ordinarily, uClibc gets the timezone information exclusively from the
864 'TZ' environment variable. In particular, there is no support for
865 the zoneinfo directory tree or the /etc/timezone file used by glibc.
867 With this option enabled, uClibc will use the value stored in the
868 file '/etc/TZ' (default path) to obtain timezone information if the
869 'TZ' environment variable is missing or has an invalid value. The
870 file consists of a single line (newline required) of text describing
871 the timezone in the format specified for the TZ environment variable.
873 Doing 'echo CST6CDT > /etc/TZ' is enough to create a valid file.
875 http://www.opengroup.org/onlinepubs/007904975/basedefs/xbd_chap08.html
876 for details on valid settings of 'TZ'.
878 Most people will answer Y.
880 config UCLIBC_HAS_TZ_FILE_READ_MANY
881 bool "Repeatedly read the '/etc/TZ' file"
882 depends on UCLIBC_HAS_TZ_FILE
885 Answer Y to enable repeated reading of the '/etc/TZ' file even after
886 a valid value has been read. This incurs the overhead of an
887 open/read/close for each tzset() call (explicit or implied). However,
888 setting this will allow applications to update their timezone
889 information if the contents of the file change.
891 Most people will answer Y.
893 config UCLIBC_TZ_FILE_PATH
894 string "Path to the 'TZ' file for setting the global timezone"
895 depends on UCLIBC_HAS_TZ_FILE
898 This is the path to the 'TZ' file.
900 Most people will use the default of '/etc/TZ'.
902 config UCLIBC_FALLBACK_TO_ETC_LOCALTIME
903 bool "Use /etc/localtime as a fallback"
904 depends on UCLIBC_HAS_TZ_FILE
907 Answer Y to try to use /etc/localtime file.
908 On glibc systems this file (if it is in TZif2 format)
909 contains timezone string at the end.
911 Most people will answer Y.
915 menu "Advanced Library Settings"
917 config UCLIBC_PWD_BUFFER_SIZE
918 int "Buffer size for getpwnam() and friends"
922 This sets the value of the buffer size for getpwnam() and friends.
923 By default, this is 256. (For reference, glibc uses 1024).
924 The value can be found using sysconf() with the _SC_GETPW_R_SIZE_MAX
927 config UCLIBC_GRP_BUFFER_SIZE
928 int "Buffer size for getgrnam() and friends"
932 This sets the value of the buffer size for getgrnam() and friends.
933 By default, this is 256. (For reference, glibc uses 1024).
934 The value can be found using sysconf() with the _SC_GETGR_R_SIZE_MAX
937 comment "Support various families of functions"
939 config UCLIBC_LINUX_MODULE_26
940 bool "Linux kernel module functions (2.6)"
943 delete_module, init_module
944 are used in linux for loadable kernel modules.
946 Say N if you do not use kernel modules.
948 config UCLIBC_LINUX_MODULE_24
949 bool "Linux kernel module functions (<2.6)"
950 depends on !TARGET_bfin && !TARGET_c6x
952 create_module, query_module
953 are used in linux (prior to 2.6) for loadable kernel modules.
955 Say N if you do not use kernel modules, or you only support
958 config UCLIBC_LINUX_SPECIFIC
959 bool "Linux specific functions"
962 accept4(), bdflush(),
963 capget(), capset(), eventfd(), fstatfs(),
964 inotify_*(), ioperm(), iopl(),
965 madvise(), modify_ldt(), pipe2(), personality(),
966 prctl()/arch_prctl(), pivot_root(), modify_ldt(),
967 ppoll(), readahead(), reboot(), remap_file_pages(),
968 sched_getaffinity(), sched_setaffinity(), sendfile(),
969 setfsgid(), setfsuid(), setresgid(), setresuid(),
970 splice(), vmsplice(), tee(), signalfd(), swapoff(), swapon(),
971 sync_file_range(), _sysctl(), sysinfo(), timerfd_*(), vhangup(),
974 config UCLIBC_HAS_GNU_ERROR
975 bool "Support GNU extensions for error-reporting"
978 Support for the GNU-specific error(), error_at_line(),
979 void (* error_print_progname)(), error_message_count
980 functions and variables. Some GNU packages
981 utilize these for extra useful output, but in general
984 If unsure, just answer N.
986 config UCLIBC_BSD_SPECIFIC
987 bool "BSD specific functions"
990 mincore(), getdomainname(), setdomainname()
994 config UCLIBC_HAS_BSD_ERR
995 bool "BSD err functions"
998 These functions are non-standard BSD extensions.
999 err(), errx(), warn(), warnx(), verr(), verrx(), vwarn(), vwarnx()
1003 config UCLIBC_HAS_OBSOLETE_BSD_SIGNAL
1004 bool "BSD obsolete signal functions"
1006 These functions are provided as a compatibility interface for
1007 programs that make use of the historical System V signal API.
1008 This API is obsolete:
1009 new applications should use the POSIX signal API (sigaction(2),
1010 sigprocmask(2), etc.).
1013 sigset(), sighold(), sigrelse(), sigignore()
1017 config UCLIBC_HAS_OBSOLETE_SYSV_SIGNAL
1018 bool "SYSV obsolete signal functions"
1020 Use of sysv_signal() should be avoided; use sigaction(2) instead.
1024 config UCLIBC_NTP_LEGACY
1025 bool "ntp_*() aliases"
1027 Provide legacy aliases for ntp functions:
1028 ntp_adjtime(), ntp_gettime()
1030 It is safe to say N here.
1032 config UCLIBC_SV4_DEPRECATED
1033 bool "Enable SVr4 deprecated functions"
1035 These functions are DEPRECATED in System V release 4.
1036 Say N unless you desparately need one of the functions below:
1038 ustat() [use statfs(2) in your code instead]
1040 config UCLIBC_HAS_REALTIME
1041 bool "Realtime-related family of SUSv functions"
1044 These functions are part of the Timers option and need not
1045 be available on all implementations.
1046 Includes AIO, message-queue, scheduler, semaphore functions:
1061 clock_getres(), clock_gettime(), clock_settime()
1063 mlockall(), munlockall()
1075 sched_get_priority_max(), sched_get_priority_min()
1076 sched_getscheduler()
1077 sched_rr_get_interval()
1079 sched_setscheduler()
1086 sem_trywait(), sem_wait()
1089 sigtimedwait(), sigwaitinfo()
1092 timer_getoverrun(), timer_gettime(), timer_settime()
1094 config UCLIBC_HAS_ADVANCED_REALTIME
1095 bool "Advanced realtime-related family of SUSv functions"
1097 depends on UCLIBC_HAS_REALTIME
1099 These functions are part of the Timers option and need not
1100 be available on all implementations.
1102 clock_getcpuclockid()
1111 posix_spawnattr_destroy(), posix_spawnattr_init()
1112 posix_spawnattr_getflags(), posix_spawnattr_setflags()
1113 posix_spawnattr_getpgroup(), posix_spawnattr_setpgroup()
1114 posix_spawnattr_getschedparam(), posix_spawnattr_setschedparam()
1115 posix_spawnattr_getschedpolicy(), posix_spawnattr_setschedpolicy()
1116 posix_spawnattr_getsigdefault(), posix_spawnattr_setsigdefault()
1117 posix_spawnattr_getsigmask(), posix_spawnattr_setsigmask()
1118 posix_spawn_file_actions_addclose()
1119 posix_spawn_file_actions_adddup2()
1120 posix_spawn_file_actions_addopen()
1121 posix_spawn_file_actions_destroy()
1122 posix_spawn_file_actions_init()
1125 posix_typed_mem_get_info()
1126 pthread_mutex_timedlock()
1129 #config UCLIBC_HAS_TERMIOS
1130 # bool "termios functions"
1133 # Get and set terminal attributes, line control, get and set baud
1135 # termios(), tcgetattr(), tcsetattr(), tcsendbreak(), tcdrain(),
1136 # tcflush(), tcflow(), cfmakeraw(), cfgetospeed(), cfgetispeed(),
1137 # cfsetispeed(), cfsetospeed(), cfsetspeed()
1141 config UCLIBC_HAS_EPOLL
1145 epoll_create(), epoll_ctl(), epoll_wait() functions.
1147 config UCLIBC_HAS_XATTR
1148 bool "Extended Attributes"
1151 Extended Attributes support.
1166 Say N unless you need support for extended attributes and the
1167 filesystems do actually support them.
1169 config UCLIBC_HAS_PROFILING
1170 bool "Profiling support"
1173 gcc's -finstrument-functions needs these.
1175 Most people can safely answer N.
1177 config UCLIBC_HAS_CRYPT_IMPL
1178 bool "libcrypt support"
1181 libcrypt contains crypt(), setkey() and encrypt()
1183 config UCLIBC_HAS_SHA256_CRYPT_IMPL
1184 bool "libcrypt SHA256 support"
1185 depends on UCLIBC_HAS_CRYPT_IMPL
1187 This adds support for SHA256 password hashing via the crypt() function.
1188 Say N here if you do not need SHA256 crypt support.
1190 config UCLIBC_HAS_SHA512_CRYPT_IMPL
1191 bool "libcrypt SHA512 support"
1192 depends on UCLIBC_HAS_CRYPT_IMPL
1194 This adds support for SHA512 password hashing via the crypt() function.
1195 Say N here if you do not need SHA512 crypt support.
1197 config UCLIBC_HAS_CRYPT_STUB
1198 bool "libcrypt stubs"
1200 depends on !UCLIBC_HAS_CRYPT_IMPL
1202 Standards mandate that crypt(3) provides a stub if it is unavailable.
1203 If you enable this option then stubs for
1204 crypt(), setkey() and encrypt()
1205 will be provided in a small libcrypt.
1207 config UCLIBC_HAS_CRYPT
1209 depends on UCLIBC_HAS_CRYPT_IMPL || UCLIBC_HAS_CRYPT_STUB
1212 menuconfig UCLIBC_HAS_NETWORK_SUPPORT
1213 bool "Networking Support"
1216 Say N here if you do not need network support.
1218 if UCLIBC_HAS_NETWORK_SUPPORT
1219 config UCLIBC_HAS_SOCKET
1220 bool "Socket support"
1223 If you want to include support for sockets then answer Y.
1225 config UCLIBC_HAS_IPV4
1226 bool "IP version 4 support"
1228 select UCLIBC_HAS_SOCKET
1230 If you want to include support for the Internet Protocol
1231 (IP version 4) then answer Y.
1233 Most people will say Y.
1235 config UCLIBC_HAS_IPV6
1236 bool "IP version 6 support"
1237 select UCLIBC_HAS_SOCKET
1239 If you want to include support for the next version of the Internet
1240 Protocol (IP version 6) then answer Y.
1242 Most people should answer N.
1244 config UCLIBC_HAS_RPC
1245 bool "Remote Procedure Call (RPC) support"
1246 # RPC+socket-ipvX doesn't currently work.
1247 depends on UCLIBC_HAS_IPV4 || UCLIBC_HAS_IPV6
1249 If you want to include RPC support, enable this. RPC is rarely used
1250 for anything except for the NFS filesystem. Unless you plan to use
1251 NFS, you can probably leave this set to N and save some space.
1253 If you need to use NFS then you should answer Y.
1255 config UCLIBC_HAS_FULL_RPC
1256 bool "Full RPC support"
1257 depends on UCLIBC_HAS_RPC
1258 default y if !HAVE_SHARED
1260 Normally we enable just enough RPC support for things like rshd and
1261 nfs mounts to work. If you find you need the rest of the RPC stuff,
1262 then enable this option. Most people can safely answer N.
1264 config UCLIBC_HAS_REENTRANT_RPC
1265 bool "Reentrant RPC support"
1266 depends on UCLIBC_HAS_RPC
1267 default y if !HAVE_SHARED
1269 Most packages utilize the normal (non-reentrant) RPC functions, but
1270 some (like exportfs from nfs-utils) need these reentrant versions.
1272 Most people can safely answer N.
1274 config UCLIBC_USE_NETLINK
1275 bool "Use netlink to query interfaces"
1276 depends on UCLIBC_HAS_SOCKET
1278 In newer versions of Linux (2.4.17+), support was added for querying
1279 network device information via netlink rather than the old style
1280 ioctl's. Most of the time, the older ioctl style is sufficient (and
1281 it is smaller than netlink), but if you find that not all of your
1282 devices are being returned by the if_nameindex() function, you will
1283 have to use the netlink implementation.
1285 Most people can safely answer N.
1287 config UCLIBC_SUPPORT_AI_ADDRCONFIG
1288 bool "Support the AI_ADDRCONFIG flag"
1289 depends on UCLIBC_USE_NETLINK
1291 The implementation of AI_ADDRCONFIG is aligned with the glibc
1292 implementation using netlink to query interfaces to find both
1293 ipv4 and ipv6 support. This is only needed if an application uses
1294 the AI_ADDRCONFIG flag.
1296 Most people can safely answer N.
1298 config UCLIBC_HAS_BSD_RES_CLOSE
1299 bool "Support res_close() (bsd-compat)"
1301 Answer Y if you desperately want to support BSD compatibility in
1304 Most people will say N.
1306 config UCLIBC_HAS_COMPAT_RES_STATE
1307 bool "Use compatible but bloated _res"
1310 Answer Y if you build network utilities and they muck with resolver
1311 internals a lot (_res global structure). uclibc does not use most
1312 of _res.XXX fields, and with this option OFF they won't even exist.
1313 Which will make e.g. dig build fail.
1314 Answering N saves around 400 bytes in bss.
1316 config UCLIBC_HAS_EXTRA_COMPAT_RES_STATE
1317 bool "Use extra compatible but extra bloated _res"
1319 Answer Y if selecting UCLIBC_HAS_COMPAT_RES_STATE is not enough.
1320 As far as I can say, this should never be needed.
1322 config UCLIBC_HAS_RESOLVER_SUPPORT
1323 bool "DNS resolver functions"
1324 select UCLIBC_HAS_COMPAT_RES_STATE
1325 depends on UCLIBC_HAS_IPV4 || UCLIBC_HAS_IPV6
1327 Provide implementations for DNS resolver functions.
1328 In particular, the following functions will be added to the
1331 ns_get16, ns_get32, ns_put16, ns_put32
1333 config UCLIBC_HAS_LIBRESOLV_STUB
1334 bool "Provide libresolv stub"
1336 Provide a dummy resolv library.
1338 config UCLIBC_HAS_LIBNSL_STUB
1339 bool "Provide libnsl stub"
1341 Provide a dummy nsl library.
1346 menu "String and Stdio Support"
1348 config UCLIBC_HAS_STRING_GENERIC_OPT
1349 bool "Use faster (but larger) generic string functions"
1352 Answer Y to use the (tweaked) glibc generic string functions.
1354 In general, they are faster (but 3-5K larger) than the base
1355 uClibc string functions which are optimized solely for size.
1357 Many people will answer Y.
1359 config UCLIBC_HAS_STRING_ARCH_OPT
1360 bool "Use arch-specific assembly string functions (where available)"
1363 Answer Y to use any archtecture-specific assembly language string
1364 functions available for this target plaform.
1366 Note that assembly implementations are not available for all string
1367 functions, so some generic (written in C) string functions may
1370 These are small and fast, the only reason _not_ to say Y here is
1371 for debugging purposes.
1373 config UCLIBC_HAS_CTYPE_TABLES
1374 bool "Use Table Versions Of 'ctype.h' Functions."
1377 Answer Y to use table versions of the 'ctype.h' functions.
1378 While the non-table versions are often smaller when building
1379 statically linked apps, they work only in stub locale mode.
1381 Most people will answer Y.
1383 config UCLIBC_HAS_CTYPE_SIGNED
1384 bool "Support Signed Characters In 'ctype.h' Functions."
1385 depends on UCLIBC_HAS_CTYPE_TABLES
1388 Answer Y to enable support for passing signed char values to
1389 the 'ctype.h' functions. ANSI/ISO C99 and SUSv3 specify that
1390 these functions are only defined for unsigned char values and
1391 EOF. However, glibc allows negative signed char values as well
1392 in order to support 'broken old programs'.
1394 Most people will answer Y.
1397 prompt "ctype argument checking"
1398 depends on UCLIBC_HAS_CTYPE_TABLES
1399 default UCLIBC_HAS_CTYPE_UNSAFE
1401 Please select the invalid arg behavior you want for the 'ctype'
1404 The 'ctype' functions are now implemented using table lookups, with
1405 the arg being the index. This can result in incorrect memory accesses
1406 or even segfaults for args outside of the allowed range.
1408 NOTE: This only affects the 'ctype' _functions_. It does not affect
1409 the macro implementations.
1411 config UCLIBC_HAS_CTYPE_UNSAFE
1412 bool "Do not check -- unsafe"
1414 config UCLIBC_HAS_CTYPE_CHECKED
1415 bool "Detect and handle appropriately"
1417 config UCLIBC_HAS_CTYPE_ENFORCED
1418 bool "Issue a diagnostic and abort()"
1423 config UCLIBC_HAS_WCHAR
1424 bool "Wide Character Support"
1426 Answer Y to enable wide character support. This will make uClibc
1427 much larger. It is also currently required for locale support.
1429 Most people will answer N.
1431 config UCLIBC_HAS_LOCALE
1432 bool "Locale Support"
1433 select UCLIBC_HAS_WCHAR
1434 select UCLIBC_HAS_CTYPE_TABLES
1436 uClibc now has full ANSI/ISO C99 locale support (except for
1437 wcsftime() and collating items in regex). Be aware that enabling
1438 this option will make uClibc much larger.
1440 Enabling UCLIBC_HAS_LOCALE with the default set of supported locales
1441 (169 UTF-8 locales, and 144 locales for other codesets) will enlarge
1442 uClibc by around 300k. You can reduce this size by building your own
1443 custom set of locate data (see extra/locale/LOCALES for details).
1445 uClibc's locale support is still under development. For example,
1446 codesets using shift states are not currently supported. Support is
1447 planned in the next iteration of locale support.
1449 Answer Y to enable locale support. Most people will answer N.
1453 prompt "Locale data"
1454 depends on UCLIBC_HAS_LOCALE
1455 default UCLIBC_BUILD_ALL_LOCALE
1457 config UCLIBC_BUILD_ALL_LOCALE
1459 depends on UCLIBC_HAS_LOCALE
1461 This builds all the locales that are available on your
1464 config UCLIBC_BUILD_MINIMAL_LOCALE
1465 bool "Only selected locales"
1466 depends on UCLIBC_HAS_LOCALE
1468 If you do not need all locales that are available on your
1469 host-box, then set this to 'Y'.
1471 config UCLIBC_PREGENERATED_LOCALE_DATA
1472 bool "Use Pre-generated Locale Data"
1473 depends on UCLIBC_HAS_LOCALE
1475 Use pre-built locale data.
1477 Note that these pregenerated locales are sensitive to your
1478 target architecture (endianess, bitcount).
1480 Saying N here is highly recommended.
1484 config UCLIBC_BUILD_MINIMAL_LOCALES
1485 string "locales to use"
1486 depends on UCLIBC_BUILD_MINIMAL_LOCALE
1489 Space separated list of locales to use.
1496 config UCLIBC_DOWNLOAD_PREGENERATED_LOCALE_DATA
1497 bool "Automagically Download the Pre-generated Locale Data (if necessary)"
1498 depends on UCLIBC_PREGENERATED_LOCALE_DATA
1500 If you would like the build process to use 'wget' to automatically
1501 download the pregenerated locale data, enable this option. Otherwise
1502 you will need to obtain the locale data yourself from:
1503 http://www.uclibc.org/downloads/uClibc-locale-*.tgz
1504 and place the uClibc-locale-*.tgz tarball in the extra/locale/
1507 Note that the use of pregenerated locale data is discouraged.
1509 config UCLIBC_HAS_XLOCALE
1510 bool "Extended Locale Support (experimental/incomplete)"
1511 depends on UCLIBC_HAS_LOCALE
1513 Answer Y to enable extended locale support similar to that provided
1514 by glibc. This is primarily intended to support libstd++
1516 However, it also allows thread-specific locale selection via
1519 Most people will answer N.
1521 config UCLIBC_HAS_HEXADECIMAL_FLOATS
1522 bool "Support hexadecimal float notation"
1523 depends on UCLIBC_HAS_CTYPE_TABLES
1524 depends on UCLIBC_HAS_FLOATS
1526 Answer Y to enable support for hexadecimal float notation in the
1527 (wchar and) char string to floating point conversion functions, as
1528 well as support for the %a and %A conversion specifiers in the
1529 *printf() and *scanf() functions.
1531 Most people will answer N.
1533 config UCLIBC_HAS_GLIBC_DIGIT_GROUPING
1534 bool "Support glibc's \"'\" flag for allowing locale-specific digit grouping"
1535 depends on UCLIBC_HAS_LOCALE
1536 depends on UCLIBC_HAS_FLOATS
1538 Answer Y to enable support for glibc's \"'\" flag for allowing
1539 locale-specific digit grouping in base 10 integer conversions and
1540 appropriate floating point conversions in the *printf() and *scanf()
1543 Most people will answer N.
1545 config UCLIBC_HAS_SCANF_LENIENT_DIGIT_GROUPING
1546 bool "Do not require digit grouping when the \"'\" flag is specified"
1547 depends on UCLIBC_HAS_GLIBC_DIGIT_GROUPING
1550 Answer Y to make digit grouping optional when the \"'\" flag is
1552 This is the standard glibc behavior. If the initial string of digits
1553 exceeds the maximum group number, the input will be treated as a
1554 normal non-grouped number.
1556 Most people will answer N.
1558 config UCLIBC_HAS_GLIBC_CUSTOM_PRINTF
1559 bool "Support glibc's register_printf_function() (glibc-compat)"
1560 depends on !USE_OLD_VFPRINTF
1562 Answer Y to support glibc's register_printf_function() to allow an
1563 application to add its own printf conversion specifiers.
1564 parse_printf_format() is also enabled.
1566 NOTE: Limits the number or registered specifiers to 10.
1567 NOTE: Requires new conversion specifiers to be ASCII
1568 characters (0-0x7f). This is to avoid problems with processing
1569 format strings in locales with different multibyte conversions.
1571 Most people will answer N.
1573 config USE_OLD_VFPRINTF
1574 bool "Use the old vfprintf implementation"
1575 depends on !UCLIBC_HAS_WCHAR
1577 Set to true to use the old vfprintf instead of the new. This is
1578 roughly C89 compliant with some extensions, and is much smaller.
1579 However, it does not support wide chars, positional args, or glibc
1580 custom printf specifiers.
1582 Most people will answer N.
1584 config UCLIBC_PRINTF_SCANF_POSITIONAL_ARGS
1585 int "Maximum number of positional args. Either 0 or >= 9."
1586 depends on !USE_OLD_VFPRINTF
1589 Set the maximum number of positional args supported by the
1590 printf/scanf functions. The Single Unix Specification Version 3
1591 requires a minimum value of 9. Setting this to a value lower than
1592 9 will disable positional arg support and cause the NL_ARGMAX macro
1593 in limits.h to be #undef'd.
1595 WARNING! The workspace to support positional args is currently
1596 allocated on the stack. You probably don't want to set
1597 this to too high a value.
1599 Most people will answer 9.
1602 prompt "Stdio buffer size"
1603 default UCLIBC_HAS_STDIO_BUFSIZ_4096
1605 Please select a value for BUFSIZ. This will be used by the
1606 stdio subsystem as the default buffer size for a file, and
1607 affects fopen(), setvbuf(), etc.
1609 NOTE: Setting this to 'none' will disable buffering completely.
1610 However, BUFSIZ will still be defined in stdio.h as 256 because
1611 many applications use this value.
1613 config UCLIBC_HAS_STDIO_BUFSIZ_NONE
1614 bool "none (WARNING - BUFSIZ will be 256 in stdio.h)"
1615 depends on !UCLIBC_HAS_WCHAR
1617 config UCLIBC_HAS_STDIO_BUFSIZ_256
1618 bool "256 (minimum ANSI/ISO C99 value)"
1620 config UCLIBC_HAS_STDIO_BUFSIZ_512
1623 config UCLIBC_HAS_STDIO_BUFSIZ_1024
1626 config UCLIBC_HAS_STDIO_BUFSIZ_2048
1629 config UCLIBC_HAS_STDIO_BUFSIZ_4096
1632 config UCLIBC_HAS_STDIO_BUFSIZ_8192
1635 # If you add more choices, you will need to update uClibc_stdio.h.
1640 prompt "Stdio builtin buffer size (uClibc-specific)"
1641 depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
1642 default UCLIBC_HAS_STDIO_BUILTIN_BUFFER_NONE
1644 When a FILE is created with fopen(), an attempt is made to allocate
1645 a BUFSIZ buffer for it. If the allocation fails, fopen() will still
1646 succeed but the FILE will be unbuffered.
1648 This option adds a small amount of space to each FILE to act as an
1649 emergency buffer in the event of a buffer allocation failure.
1651 Most people will answer None.
1653 config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_NONE
1656 config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_4
1659 config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_8
1662 # If you add more choices, you will need to update uClibc_stdio.h.
1666 config UCLIBC_HAS_STDIO_SHUTDOWN_ON_ABORT
1667 bool "Attempt to shutdown stdio subsystem when abort() is called."
1669 ANSI/ISO C99 requires abort() to be asyn-signal-safe. So there was
1670 a behavioral change made in SUSv3. Previously, abort() was required
1671 to have the affect of fclose() on all open streams. The wording has
1672 been changed to "may" from "shall".
1674 Most people will answer N.
1676 config UCLIBC_HAS_STDIO_GETC_MACRO
1677 bool "Provide a macro version of getc()"
1678 depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
1681 Provide a macro version of getc().
1683 Most people will answer Y.
1685 config UCLIBC_HAS_STDIO_PUTC_MACRO
1686 bool "Provide a macro version of putc()"
1687 depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
1690 Provide a macro version of putc().
1692 Most people will answer Y.
1694 config UCLIBC_HAS_STDIO_AUTO_RW_TRANSITION
1695 bool "Support auto-r/w transition"
1698 Answer Y to enable the stdio subsystem to automaticly transition
1699 between reading and writing. This relaxes the ANSI/ISO C99
1702 When a file is opened with update mode ('+' as the second or third
1703 character in the list of mode argument values), both input and output
1704 may be performed on the associated stream. However, output shall not
1705 be directly followed by input without an intervening call to the
1706 fflush function or to a file positioning function (fseek, fsetpos,
1707 or rewind), and input shall not be directly followed by output without
1708 an intervening call to a file positioning function, unless the input
1709 operation encounters endÂofÂfile.
1711 Most people will answer Y.
1713 config UCLIBC_HAS_FOPEN_LARGEFILE_MODE
1714 bool "Support an fopen() 'F' flag for large file mode (uClibc-specific)"
1715 depends on UCLIBC_HAS_LFS
1717 Answer Y to enable a uClibc-specific extension to allow passing an
1718 additional 'F' flag in the mode string for fopen() to specify that
1719 the file should be open()ed with the O_LARGEFILE flag set.
1721 Most people will answer N.
1723 config UCLIBC_HAS_FOPEN_EXCLUSIVE_MODE
1724 bool "Support an fopen() 'x' flag for exclusive mode (glibc-compat)"
1726 Answer Y to support a glibc extension to allow passing
1727 additional 'x' flag in the mode string for fopen() to specify that
1728 the file should be open()ed with the O_EXCL flag set.
1730 Most people will answer N.
1732 config UCLIBC_HAS_FOPEN_CLOSEEXEC_MODE
1733 bool "Support an fopen() 'e' flag for close-on-exec mode (glibc-compat)"
1735 Answer Y to support a glibc extension to allow passing
1736 additional 'e' flag in the mode string for fopen() to specify that
1737 the file should be open()ed with the O_CLOEXEC flag set.
1739 Most people will answer N.
1741 config UCLIBC_HAS_GLIBC_CUSTOM_STREAMS
1742 bool "Support fmemopen(), open_memstream(), and fopencookie() (glibc-compat)"
1744 Answer Y to support the glibc 'custom stream' extension functions
1745 fmemopen(), open_memstream(), and fopencookie().
1747 NOTE: There are some minor differences regarding seeking behavior.
1749 Most people will answer N.
1751 config UCLIBC_HAS_PRINTF_M_SPEC
1752 bool "Support the '%m' specifier in printf format strings (glibc-compat)"
1754 Answer Y to support a glibc extension to interpret '%m' in printf
1755 format strings as an instruction to output the error message string
1756 (as generated by strerror) corresponding to the current value of
1759 Most people will answer N.
1761 config UCLIBC_HAS_ERRNO_MESSAGES
1762 bool "Include the errno message text in the library"
1765 Answer Y if you want to include the errno message text in the
1766 library. This adds about 3K to the library, but enables strerror()
1767 to generate text other than 'Unknown error <number>'.
1769 Most people will answer Y.
1771 config UCLIBC_HAS_SYS_ERRLIST
1772 bool "Support sys_errlist[] (obsolete-compat)"
1773 depends on UCLIBC_HAS_ERRNO_MESSAGES
1775 Answer Y if you want to support the obsolete sys_errlist[].
1776 This adds about 0.5k to the library, except for the mips
1777 arch where it adds over 4K.
1779 WARNING! In the future, support for sys_errlist[] may be unavailable
1780 in at least some configurations. In fact, it may be removed
1783 Most people will answer N.
1785 Application writers: use the strerror(3) function.
1787 config UCLIBC_HAS_SIGNUM_MESSAGES
1788 bool "Include the signum message text in the library"
1791 Answer Y if you want to include the signum message text in the
1792 library. This adds about 0.5K to the library, but enables strsignal()
1793 to generate text other than 'Unknown signal <number>'.
1795 Most people will answer Y.
1797 config UCLIBC_HAS_SYS_SIGLIST
1798 bool "Support sys_siglist[] (bsd-compat)"
1799 depends on UCLIBC_HAS_SIGNUM_MESSAGES
1801 Answer Y if you want to support sys_siglist[].
1803 WARNING! In the future, support for sys_siglist[] may be unavailable
1804 in at least some configurations. In fact, it may be removed
1807 Most people will answer N.
1809 config UCLIBC_HAS_GETTEXT_AWARENESS
1810 bool "Include gettext awareness"
1811 depends on UCLIBC_HAS_LOCALE && UCLIBC_MJN3_ONLY
1813 NOTE!!! Not yet integrated with strerror and strsignal. NOTE!!!
1815 Answer Y if you want to include weak stub gettext support and
1816 make the *strerror*() and strsignal() functions gettext-aware.
1818 Currently, to get functional gettext functionality you will need
1821 Most people will answer N.
1823 config UCLIBC_HAS_GNU_GETOPT
1824 bool "Support gnu getopt"
1827 Answer Y if you want to include full gnu getopt() instead of a
1828 (much smaller) SUSv3 compatible getopt().
1830 Most people will answer Y.
1832 config UCLIBC_HAS_STDIO_FUTEXES
1833 bool "Use futexes for multithreaded I/O locking"
1834 depends on UCLIBC_HAS_THREADS_NATIVE
1836 If you want to compile uClibc to use futexes for low-level
1837 I/O locking, answer Y. Otherwise, answer N.
1839 config UCLIBC_HAS_GETOPT_LONG
1840 bool "Support getopt_long/getopt_long_only"
1841 depends on !UCLIBC_HAS_GNU_GETOPT
1844 Answer Y if you want to include getopt_long[_only() used by many
1847 Most people will answer Y.
1849 config UCLIBC_HAS_GNU_GETSUBOPT
1850 bool "Support glibc getsubopt"
1853 Answer Y if you want to include glibc getsubopt() instead of a
1854 smaller SUSv3 compatible getsubopt().
1856 Most people will answer Y.
1862 config UCLIBC_HAS_REGEX
1863 bool "Regular Expression Support"
1866 POSIX regular expression code is really big -- 53k all by itself.
1867 If you don't use regular expressions, turn this off and save space.
1868 Of course, if you only statically link, leave this on, since it will
1869 only be included in your apps if you use regular expressions.
1871 config UCLIBC_HAS_REGEX_OLD
1872 bool "Use the older (stable) regular expression code"
1873 depends on UCLIBC_HAS_REGEX
1876 There are two versions of regex. The older (stable) version has
1877 been in uClibc for quite a long time but hasn't seen too many
1878 updates. It also has some known issues when dealing with uncommon
1879 corner cases and multibyte/unicode strings. However, it is quite
1880 a bit smaller than the newer version.
1882 If the older version has worked for you and you don't need unicode
1883 support, then stick with the old version (and say Y here).
1884 Otherwise, you should use the new version (and say N here).
1886 config UCLIBC_HAS_FNMATCH
1887 bool "fnmatch Support"
1892 config UCLIBC_HAS_FNMATCH_OLD
1893 bool "Use the older (stable) fnmatch code"
1894 depends on UCLIBC_HAS_FNMATCH
1897 There are two versions of fnmatch. The older (stable) version has
1898 been in uClibc for quite a long time but hasn't seen too many
1899 updates. It also has some known issues when dealing with uncommon
1900 corner cases and multibyte/unicode strings. However, it is quite
1901 a bit smaller than the newer version.
1903 If the older version has worked for you and you don't need unicode
1904 support, then stick with the old version (and say Y here).
1905 Otherwise, you should use the new version (and say N here).
1907 config UCLIBC_HAS_WORDEXP
1908 bool "Support the wordexp() interface"
1909 depends on UCLIBC_HAS_GLOB
1911 The SuSv3 wordexp() interface performs word expansions per the Shell
1912 and Utilities volume of IEEE Std 1003.1-2001, Section 2.6. It is
1913 intended for use by applications that want to implement all of the
1914 standard Bourne shell expansions on input data.
1916 This interface is rarely used, and very large. Unless you have a
1917 pressing need for wordexp(), you should probably answer N.
1919 config UCLIBC_HAS_NFTW
1920 bool "Support the nftw() interface"
1922 The SuSv3 nftw() interface is used to recursively descend
1923 directory paths while repeatedly calling a function.
1925 This interface is rarely used, and adds around 4.5k. Unless you have
1926 a pressing need for nftw(), you should probably answer N.
1928 config UCLIBC_HAS_FTW
1929 bool "Support the ftw() interface (SUSv4-obsolete)"
1930 depends on UCLIBC_SUSV4_LEGACY
1932 The SuSv3 ftw() interface is used to recursively descend
1933 directory paths while repeatedly calling a function.
1935 This interface is rarely used, and adds around 4.5k. Unless you have
1936 a pressing need for ftw(), you should probably answer N.
1938 config UCLIBC_HAS_FTS
1939 bool "Support the fts() interface (bsd-compat)"
1941 The fts functions are provided for traversing UNIX file hierarchies.
1943 This interface is currently used by the elfutils and adds
1945 You should port your application to use the POSIX nftw()
1948 Unless you need to build/use elfutils, you should prolly answer N.
1950 config UCLIBC_HAS_GLOB
1951 bool "Support the glob() interface"
1952 depends on UCLIBC_HAS_FNMATCH
1956 The glob interface is somewhat large (weighing in at about 2,5k). It
1957 is used fairly often, but is an option since people wanting to go for
1958 absolute minimum size may wish to omit it.
1960 Most people will answer Y.
1962 config UCLIBC_HAS_GNU_GLOB
1963 bool "Support gnu glob() interface"
1964 depends on UCLIBC_HAS_GLOB
1966 The gnu glob interface is somewhat larger (weighing in at about 4,2k)
1967 than it's SuSv3 counterpart (and is out of date). It is an old copy
1968 from glibc and does not support all the GNU specific options.
1970 Answer Y if you want to include full gnu glob() instead of the smaller
1971 SUSv3 compatible glob().
1973 Most people will answer N.
1975 config UCLIBC_HAS_UTMPX
1976 bool "utmpx based support for tracking login/logouts to/from the system"
1978 Answer y to enable support for accessing user accounting database.
1979 It can be used to track all login/logout to the system.
1981 If unsure, just answer N.
1988 menu "Library Installation Options"
1990 config RUNTIME_PREFIX
1991 string "uClibc runtime library directory"
1992 default "/usr/$(TARGET_ARCH)-linux-uclibc/"
1994 RUNTIME_PREFIX is the directory into which the uClibc runtime
1995 libraries will be installed. The result will look something
1998 lib/ <contains all runtime libraries>
1999 usr/bin/ldd <the ldd utility program>
2000 sbin/ldconfig <the ldconfig utility program>
2001 This value is used by the 'make install' Makefile target. Since this
2002 directory is compiled into the shared library loader, you will need to
2003 recompile uClibc if you change this value...
2005 For a typical target system this should be set to "/", such that
2006 'make install' will install /lib/libuClibc-<VERSION>.so
2009 string "uClibc development environment directory"
2010 default "/usr/$(TARGET_ARCH)-linux-uclibc/usr/"
2012 DEVEL_PREFIX is the directory into which the uClibc development
2013 environment will be installed. The result will look something
2016 lib/ <contains static libs>
2017 include/ <Where all the header files go>
2018 This value is used by the 'make install' Makefile target when
2019 installing a uClibc development environment.
2021 For a typical target system this should be set to "/usr", such that
2022 'make install' will install /usr/include/<header files>.
2025 string "library path component"
2028 Path component where libraries reside.
2030 For a typical target system this should be set to "lib", such that
2031 'make install' will install libraries to "/lib" and "/usr/lib"
2033 DEVEL_PREFIX/MULTILIB_DIR
2034 RUNTIME_PREFIX/MULTILIB_DIR
2036 Other settings may include "lib32" or "lib64".
2038 config HARDWIRED_ABSPATH
2039 bool "Hardwire absolute paths into linker scripts"
2042 This prepends absolute paths to the libraries mentioned in linker
2043 scripts such as libc.so.
2045 This is a build time optimization. It has no impact on dynamic
2046 linking at runtime, which doesn't use linker scripts.
2048 You must disable this to use uClibc with old non-sysroot toolchains,
2049 such as the prebuilt binary cross compilers at:
2050 http://uclibc.org/downloads/binaries
2052 The amount of time saved by this optimization is actually too small to
2053 measure. The linker just had to search the library path to find the
2054 linker script, so the dentries are cache hot if it has to search the
2055 same path again. But it's what glibc does, so we do it too.
2060 menu "Security options"
2062 config UCLIBC_BUILD_PIE
2063 bool "Build utilities as ET_DYN/PIE executables"
2064 depends on HAVE_SHARED
2065 depends on TARGET_arm || TARGET_frv || TARGET_i386 || TARGET_mips || TARGET_powerpc
2066 select FORCE_SHAREABLE_TEXT_SEGMENTS
2068 If you answer Y here, ldd and iconv are built as ET_DYN/PIE
2071 It requires gcc-3.4 and binutils-2.15 (for arm 2.16) or later.
2072 More about ET_DYN/PIE binaries on <http://pax.grsecurity.net/> .
2074 WARNING: This option also enables FORCE_SHAREABLE_TEXT_SEGMENTS, so
2075 all libraries have to be built with -fPIC or -fpic, and all
2076 assembler functions must be written as position independent
2079 config UCLIBC_HAS_ARC4RANDOM
2080 bool "Include the arc4random() function"
2082 Answer Y to support the OpenBSD-like arc4random() function. This
2083 function picks a random number between 0 and N, and will always return
2084 something even if the random driver is dead. If urandom fails then
2085 gettimeofday(2) will be used as the random seed. This function is
2086 designed to be more dependable than invoking /dev/urandom directly.
2087 OpenSSL and OpenNTPD currently support this function.
2089 Most people will answer N.
2094 config UCLIBC_HAS_SSP
2095 bool "Support for GCC stack smashing protector"
2096 depends on !HAVE_NO_SSP
2098 Add code to support GCC's -fstack-protector[-all] option to uClibc.
2099 This requires GCC 4.1 or newer. GCC does not have to provide libssp,
2100 the needed functions are added to ldso/libc instead.
2102 GCC's stack protector is a reimplementation of IBM's propolice.
2103 See http://www.trl.ibm.com/projects/security/ssp/ and
2104 http://www.linuxfromscratch.org/hints/downloads/files/ssp.txt
2107 Note that NOEXECSTACK on a kernel with address space randomization
2108 is generally sufficient to prevent most buffer overflow exploits
2109 without increasing code size. This option essentially adds debugging
2112 Most people will answer N.
2114 config UCLIBC_HAS_SSP_COMPAT
2115 bool "Support for gcc-3.x propolice smashing stack protector"
2116 depends on UCLIBC_HAS_SSP
2118 Add gcc-3.x propolice smashing stack protector to the library.
2120 This requires a patched version of GCC, supporting the
2121 -fstack-protector[-all] options, with the __guard and
2122 __stack_smash_handler functions removed from libgcc.
2123 These functions are added to ldso/libc instead.
2125 More information at:
2126 <http://www.research.ibm.com/trl/projects/security/ssp/>
2128 Most people will answer N.
2130 config SSP_QUICK_CANARY
2131 bool "Use simple guard values without accessing /dev/urandom"
2132 depends on UCLIBC_HAS_SSP
2134 Use gettimeofday(2) to define the __guard without accessing
2136 WARNING: This makes smashing stack protector vulnerable to timing
2138 Most people will answer N.
2141 prompt "Propolice protection blocking signal"
2142 depends on UCLIBC_HAS_SSP
2143 default PROPOLICE_BLOCK_ABRT if ! DODEBUG
2144 default PROPOLICE_BLOCK_SEGV if DODEBUG
2146 "abort" use SIGABRT to block offending programs.
2147 This is the default implementation.
2149 "segfault" use SIGSEGV to block offending programs.
2150 Use this for debugging.
2152 If unsure, answer "abort".
2154 config PROPOLICE_BLOCK_ABRT
2157 config PROPOLICE_BLOCK_SEGV
2162 config UCLIBC_BUILD_SSP
2163 bool "Build uClibc with -fstack-protector"
2164 depends on UCLIBC_HAS_SSP
2166 Build all uClibc libraries and executables with -fstack-protector,
2167 adding extra stack overflow checking to most uClibc functions.
2169 config UCLIBC_BUILD_RELRO
2170 bool "Build uClibc with linker option -z RELRO"
2171 depends on HAVE_SHARED
2174 Build all libraries and executables with "ld -z relro".
2176 This tells the linker to mark chunks of an executable or shared
2177 library read-only after applying dynamic relocations. (This comes
2178 up when a global const variable is initialized to the address of a
2179 function or the value of another global variable.)
2181 This is a fairly obscure option the ld man page doesn't even bother
2182 to document properly. It's a security paranoia issue that's more
2183 likely to consume memory (by allocating an extra page) rather than
2186 This is explained in more depth at
2187 http://www.airs.com/blog/archives/189
2189 Nobody is likely to care whether you say Y or N here.
2191 config UCLIBC_BUILD_NOW
2192 bool "Build uClibc with linker option -z NOW"
2193 depends on HAVE_SHARED
2195 Build all libraries and executables with "ld -z now".
2197 This tells the linker to resolve all symbols when the library is
2198 first loaded, rather than when each function is first called. This
2199 increases start-up latency by a few microseconds and may do
2200 unnecessary work (resolving symbols that are never used), but the
2201 realtime people like it for making microbenchmark timings slightly
2202 more predictable and in some cases it can be slightly faster due to
2203 CPU cache behavior (not having to fault the linker back in to do
2204 lazy symbol resolution).
2206 Most people can't tell the difference between selecting Y or N here.
2208 config UCLIBC_BUILD_NOEXECSTACK
2209 bool "Build uClibc with noexecstack marking"
2212 Mark all assembler files as noexecstack, which will mark uClibc
2213 as not requiring an executable stack. (This doesn't prevent other
2214 files you link against from claiming to need an executable stack, it
2215 just won't cause uClibc to request it unnecessarily.)
2217 This is a security thing to make buffer overflows harder to exploit.
2218 By itself, it's kind of useless, as Linus Torvalds explained in 1998:
2219 http://old.lwn.net/1998/0806/a/linus-noexec.html
2221 It only actually provides any security when combined with address
2222 space randomization, explained here: http://lwn.net/Articles/121845/
2224 Address space randomization is on by default in current linux
2225 kernels (although it can be disabled using the option
2228 You should probably say Y.
2232 menu "Development/debugging options"
2234 config CROSS_COMPILER_PREFIX
2235 string "Cross-compiling toolchain prefix"
2238 The prefix used to execute your cross-compiling toolchain. For
2239 example, if you run 'arm-linux-uclibc-gcc' to compile something,
2240 then enter 'arm-linux-uclibc-' here.
2242 config UCLIBC_EXTRA_CFLAGS
2243 string "Extra CFLAGS"
2246 Add any additional CFLAGS to be used to build uClibc.
2249 bool "Enable debugging symbols"
2250 select EXTRA_WARNINGS
2252 Say Y here if you wish to compile uClibc with debugging symbols.
2253 This will allow you to use a debugger to examine uClibc internals
2254 while applications are running. This increases the size of the
2255 library considerably and should only be used when doing development.
2256 If you are doing development and want to debug uClibc, answer Y.
2258 Otherwise, answer N.
2261 bool "Build pthread with debugging output"
2262 depends on UCLIBC_HAS_THREADS && LINUXTHREADS_OLD
2264 Enable debug output in libpthread. This is only useful when doing
2265 development in libpthread itself.
2267 Otherwise, answer N.
2270 bool "Strip libraries and executables"
2274 Say Y here if you do wish to strip all uClibc libraries and
2275 executables. No stripping increases the size of the binaries
2276 considerably, but makes it possible to debug uClibc libraries.
2277 Most people will answer Y.
2280 bool "Build with run-time assertion testing"
2282 Say Y here to include runtime assertion tests.
2283 This enables runtime assertion testing in some code, which can
2284 increase the size of the library and incur runtime overhead.
2285 If you say N, then this testing will be disabled.
2287 config SUPPORT_LD_DEBUG
2288 bool "Build the shared library loader with debugging support"
2289 depends on HAVE_SHARED
2291 Answer Y here to enable all the extra code needed to debug the uClibc
2292 native shared library loader. The level of debugging noise that is
2293 generated depends on the LD_DEBUG environment variable... Just set
2294 LD_DEBUG to something like: 'LD_DEBUG=token1,token2,.. prog' to
2295 debug your application. Diagnostic messages will then be printed to
2298 For now these debugging tokens are available:
2299 detail provide more information for some options
2300 move display copy processing
2301 symbols display symbol table processing
2302 reloc display relocation processing; detail shows the
2304 nofixups never fixes up jump relocations
2305 bindings displays the resolve processing (function calls);
2306 detail shows the relocation patch
2307 all Enable everything!
2309 The additional environment variable:
2310 LD_DEBUG_OUTPUT=file
2311 redirects the diagnostics to an output file created using
2312 the specified name and the process id as a suffix.
2314 An excellent start is simply:
2315 $ LD_DEBUG=binding,move,symbols,reloc,detail ./appname
2316 or to log everything to a file named 'logfile', try this
2317 $ LD_DEBUG=all LD_DEBUG_OUTPUT=logfile ./appname
2319 If you are doing development and want to debug uClibc's shared library
2320 loader, answer Y. Mere mortals answer N.
2322 config SUPPORT_LD_DEBUG_EARLY
2323 bool "Build the shared library loader with early debugging support"
2324 depends on HAVE_SHARED
2326 Answer Y here to if you find the uClibc shared library loader is
2327 crashing or otherwise not working very early on. This is typical
2328 only when starting a new port when you haven't figured out how to
2329 properly get the values for argc, argv, environ, etc. This method
2330 allows a degree of visibility into the very early shared library
2331 loader initialization process. If you are doing development and want
2332 to debug the uClibc shared library loader early initialization,
2333 answer Y. Mere mortals answer N.
2335 config UCLIBC_MALLOC_DEBUGGING
2336 bool "Build malloc with debugging support"
2337 depends on MALLOC || MALLOC_STANDARD
2339 Answer Y here to compile extra debugging support code into malloc.
2340 Malloc debugging output may then be enabled at runtime using the
2341 MALLOC_DEBUG environment variable.
2343 The value of MALLOC_DEBUG should be an integer, which is interpreted
2344 as a bitmask with the following bits:
2345 1 - do extra consistency checking
2346 2 - output messages for malloc/free calls and OS
2348 4 - output messages for the `MMB' layer
2349 8 - output messages for internal malloc heap manipulation
2352 Because this increases the size of malloc appreciably (due to strings
2353 etc), you should say N unless you need to debug a malloc problem.
2355 config UCLIBC_HAS_BACKTRACE
2356 bool "Add support for application self-debugging"
2357 depends on HAVE_SHARED
2359 Answer Y here to compile support for application self-debugging, by adding
2360 a new shared object "libubacktrace.so" that provides the following new
2362 backtrace, backtrace_symbols, backtrace_symbols_fd
2364 The backtrace functionality is currently supported on SH platform, and it
2365 based on dwarf2 informations to properly work, so any application that
2366 want to use backtrace needs to be built with -fexceptions flag.
2368 The symbol names may be unavailable without the use of special linker
2369 options. For systems using the GNU linker, it is necessary to use the
2370 -rdynamic linker option too. Note that names of "static" functions are not
2371 exposed, and won't be available in the backtrace.
2374 string "Compiler Warnings"
2377 Set this to the set of compiler warnings you wish to see while compiling.
2379 config EXTRA_WARNINGS
2380 bool "Enable extra annoying warnings"
2382 If you wish to build with extra warnings enabled, say Y here.
2385 bool "Compile all sources at once into an object"
2387 Set this to compile all sources at once into an object (IMA).
2388 This mode of compilation uses alot of memory but may produce
2391 Note that you need a very recent GCC for this to work, like
2392 gcc >= 4.3 plus eventually some patches.
2394 If unsure, keep the default of N.
2396 config UCLIBC_MJN3_ONLY
2397 bool "Manuel's hidden warnings"
2399 Answer Y here to see all Manuel's personal notes, warnings, and todos.
2401 Most people will answer N.
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