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.
81 config TARGET_microblaze
82 bool "microblaze (BROKEN)"
120 menu "Target Architecture Features and Options"
123 source "extra/Configs/Config.alpha"
127 source "extra/Configs/Config.arm"
131 source "extra/Configs/Config.avr32"
135 source "extra/Configs/Config.bfin"
139 source "extra/Configs/Config.cris"
143 source "extra/Configs/Config.e1"
147 source "extra/Configs/Config.frv"
151 source "extra/Configs/Config.h8300"
155 source "extra/Configs/Config.hppa"
159 source "extra/Configs/Config.i386"
163 source "extra/Configs/Config.i960"
167 source "extra/Configs/Config.ia64"
171 source "extra/Configs/Config.m68k"
175 source "extra/Configs/Config.nios"
179 source "extra/Configs/Config.nios2"
183 source "extra/Configs/Config.microblaze"
187 source "extra/Configs/Config.mips"
191 source "extra/Configs/Config.powerpc"
195 source "extra/Configs/Config.sh"
199 source "extra/Configs/Config.sh64"
203 source "extra/Configs/Config.sparc"
207 source "extra/Configs/Config.v850"
211 source "extra/Configs/Config.vax"
215 source "extra/Configs/Config.x86_64"
219 source "extra/Configs/Config.xtensa"
222 config TARGET_SUBARCH
224 default "e500" if CONFIG_E500
225 default "classic" if CONFIG_CLASSIC
226 default "sh4" if CONFIG_SH4
229 source "extra/Configs/Config.in.arch"
233 menu "General Library Settings"
240 bool "Generate only Position Independent Code (PIC)"
242 depends on !HAVE_NO_PIC
244 If you wish to build all of uClibc as PIC objects, then answer Y here.
245 If you are unsure, then you should answer N.
247 config ARCH_HAS_NO_SHARED
251 config ARCH_HAS_NO_LDSO
253 select ARCH_HAS_NO_SHARED
257 bool "Enable shared libraries"
258 depends on !ARCH_HAS_NO_SHARED
261 If you wish to build uClibc with support for shared libraries then
262 answer Y here. If you only want to build uClibc as a static library,
265 config FORCE_SHAREABLE_TEXT_SEGMENTS
266 bool "Only load shared libraries which can share their text segment"
267 depends on HAVE_SHARED
271 If you answer Y here, the uClibc native shared library loader will
272 only load shared libraries, which do not need to modify any
273 non-writable segments. These libraries haven't set the DT_TEXTREL
274 tag in the dynamic section (==> objdump).
275 All your libraries must be compiled with -fPIC or -fpic, and all
276 assembler function must be written as position independent code (PIC).
277 Enabling this option will make uClibc's shared library loader a
278 little bit smaller and guarantee that no memory will be wasted by
279 badly coded shared libraries.
281 config LDSO_LDD_SUPPORT
282 bool "Native 'ldd' support"
283 depends on HAVE_SHARED
286 Enable all the code needed to support traditional ldd,
287 which executes the shared library loader to resolve all dependencies
288 and then provide a list of shared libraries that are required for an
289 application to function. Disabling this option will make uClibc's
290 shared library loader a little bit smaller.
291 Most people will answer Y.
293 config LDSO_CACHE_SUPPORT
294 bool "Enable library loader cache (ld.so.conf)"
295 depends on HAVE_SHARED
298 Enable this to make use of /etc/ld.so.conf, the shared library loader
299 cache configuration file to support for non-standard library paths.
300 After updating this file, it is necessary to run 'ldconfig' to update
301 the /etc/ld.so.cache shared library loader cache file.
303 config LDSO_PRELOAD_FILE_SUPPORT
304 bool "Enable library loader preload file (ld.so.preload)"
305 depends on HAVE_SHARED
308 Enable this to make use of /etc/ld.so.preload. This file contains a
309 whitespace separated list of shared libraries to be loaded before
312 config LDSO_BASE_FILENAME
313 string "Shared library loader naming prefix"
314 depends on HAVE_SHARED && (LDSO_CACHE_SUPPORT || LDSO_PRELOAD_FILE_SUPPORT)
317 If you wish to support both uClibc and glibc on the same system, it
318 is necessary to set this to something other than "ld.so" to avoid
319 conflicts with glibc, which also uses "ld.so". This prevents both
320 libraries from using the same /etc/ld.so.* files. If you wish to
321 support both uClibc and glibc on the same system then you should set
322 this to "ld-uClibc.so".
324 Most people will leave this set to the default of "ld.so".
326 WARNING: Changing the default prefix could cause problems with
329 config UCLIBC_STATIC_LDCONFIG
330 bool "Link ldconfig statically"
331 depends on HAVE_SHARED
334 Enable this option to statically link the ldconfig binary.
336 Making ldconfig static can be beneficial if you have a library
337 problem and need to use ldconfig to recover. Sometimes it is
338 preferable to instead keep the size of the system down, in which
339 case you should disable this option.
342 bool "Enable ELF RUNPATH tag support"
343 depends on HAVE_SHARED
344 default y if LDSO_CACHE_SUPPORT
345 default n if !LDSO_CACHE_SUPPORT
347 ELF's may have dynamic RPATH/RUNPATH tags. These tags list paths
348 which extend the library search paths. They are really only useful
349 if a package installs libraries in non standard locations and
350 ld.so.conf support is disabled.
352 Usage of RUNPATH tags is not too common, so disabling this feature
353 should be safe for most people.
355 config LDSO_SEARCH_INTERP_PATH
356 bool "Add ldso path to lib search path"
357 depends on HAVE_SHARED
360 The ldso is told where it is being executed from and can use that
361 path to find related core libraries. This is useful by default,
362 but can be annoying in a mixed development environment.
364 i.e. if the ldso is run from /foo/boo/ldso.so, it will start its
365 library search with /foo/boo/
367 If unsure, simply say Y here.
369 config UCLIBC_CTOR_DTOR
370 bool "Support global constructors and destructors"
373 If you wish to build uClibc with support for global constructor
374 (ctor) and global destructor (dtor) support, then answer Y here.
375 When ctor/dtor support is enabled, binaries linked with uClibc must
376 also be linked with crtbegin.o and crtend.o which are provided by gcc
377 (the "*startfile:" and "*endfile:" settings in your gcc specs file
378 may need to be adjusted to include these files). This support will
379 also add a small amount of additional size to each binary compiled vs
380 uClibc. If you will be using uClibc with C++, or if you need the gcc
381 __attribute__((constructor)) and __attribute__((destructor)) to work,
382 then you definitely want to answer Y here. If you don't need ctors
383 or dtors and want your binaries to be as small as possible, then
386 config LDSO_GNU_HASH_SUPPORT
387 bool "Enable GNU hash style support"
388 depends on HAVE_SHARED
391 Newest binutils support a new hash style named GNU-hash. The dynamic
392 linker will use the new GNU-hash section (.gnu.hash) for symbol lookup
393 if present into the ELF binaries, otherwise it will use the old SysV
394 hash style (.hash). This ensures that it is completely backward
396 Further, being the hash table implementation self-contained into each
397 executable and shared libraries, objects with mixed hash style can
398 peacefully coexist in the same process.
400 If you want to use this new feature, answer Y
403 prompt "Thread support"
404 #default UCLIBC_HAS_THREADS_NATIVE if (TARGET_alpha || TARGET_arm || TARGET_i386 || TARGET_mips || TARGET_powerpc || TARGET_sh || TARGET_sh64)
405 default HAS_NO_THREADS
407 If you want to compile uClibc with pthread support, then answer Y.
408 This will increase the size of uClibc by adding a bunch of locking
409 to critical data structures, and adding extra code to ensure that
410 functions are properly reentrant.
412 config HAS_NO_THREADS
415 Disable thread support.
417 config LINUXTHREADS_OLD
418 bool "older (stable) version of linuxthreads"
419 # linuxthreads and linuxthreads.old need nanosleep()
420 select UCLIBC_HAS_REALTIME
422 There are two versions of linuxthreads. The older (stable) version
423 has been in uClibc for quite a long time but hasn't seen too many
424 updates other than bugfixes.
427 config LINUXTHREADS_NEW
428 bool "slightly newer version of linuxthreads"
430 The new version has not been tested much, and lacks ports for arches
431 which glibc does not support (like bfin/frv/etc...), but is based on
432 the latest code from glibc, so it may be the only choice for the
433 newer ports (like alpha/amd64/64bit arches and hppa).
435 config UCLIBC_HAS_THREADS_NATIVE
436 bool "Native POSIX Threading (NPTL)"
437 select UCLIBC_HAS_TLS
439 If you want to compile uClibc with NPTL support, then answer Y.
441 IMPORTANT NOTE! NPTL requires a Linux 2.6 kernel, binutils
442 at least version 2.16 and GCC with at least version 4.1.0. NPTL
443 will not work with older versions of any above sources. If you
444 ignore any of these guidelines, you do so at your own risk. Do
445 not ask for help on any of the development mailing lists.
447 !!!! WARNING !!!! BIG FAT WARNING !!!! REALLY BIG FAT WARNING !!!!
449 This is experimental code and at times it may not even build and
450 even if it does it might decide to do random damage. This code is
451 potentially hazardous to your health and sanity. It will remain
452 that way until further notice at which point this notice will
453 disappear. Thank you for your support and for not smoking.
457 config UCLIBC_HAS_THREADS
458 def_bool y if !HAS_NO_THREADS
460 config UCLIBC_HAS_TLS
461 bool "Thread-Local Storage"
462 depends on UCLIBC_HAS_THREADS_NATIVE
465 If you want to enable TLS support then answer Y.
466 This is fast an efficient way to store per-thread local data
467 which is not on stack. It needs __thread support enabled in
470 config PTHREADS_DEBUG_SUPPORT
471 bool "Build pthreads debugging support"
473 depends on UCLIBC_HAS_THREADS
475 Say Y here if you wish to be able to debug applications that use
476 uClibc's pthreads library. By enabling this option, a library
477 named libthread_db will be built. This library will be dlopen()'d
478 by gdb and will allow gdb to debug the threads in your application.
480 IMPORTANT NOTE! Because gdb must dlopen() the libthread_db library,
481 you must compile gdb with uClibc in order for pthread debugging to
484 If you are doing development and want to debug applications using
485 uClibc's pthread library, answer Y. Otherwise, answer N.
488 config UCLIBC_HAS_SYSLOG
489 bool "Syslog support"
491 depends on UCLIBC_HAS_NETWORK_SUPPORT
492 select UCLIBC_HAS_SOCKET
494 Support sending messages to the system logger.
495 This requires socket-support.
497 config UCLIBC_HAS_LFS
498 bool "Large File Support"
501 If you wish to build uClibc with support for accessing large files
502 (i.e. files greater then 2 GiB) then answer Y. Do not enable this
503 if you are using an older Linux kernel (2.0.x) that lacks large file
504 support. Enabling this option will increase the size of uClibc.
507 prompt "Malloc Implementation"
508 default MALLOC if ! ARCH_USE_MMU
509 default MALLOC_STANDARD if ARCH_USE_MMU
514 "malloc" use mmap for all allocations and so works very well on
515 MMU-less systems that do not support the brk() system call. It is
516 pretty smart about reusing already allocated memory, and minimizing
518 This is the default for uClinux MMU-less systems.
523 "malloc-simple" is trivially simple and slow as molasses. It
524 was written from scratch for uClibc, and is the simplest possible
525 (and therefore smallest) malloc implementation.
527 This uses only the mmap() system call to allocate and free memory,
528 and does not use the brk() system call at all, making it a fine
529 choice for MMU-less systems with very limited memory. It's 100%
530 standards compliant, thread safe, very small, and releases freed
531 memory back to the OS immediately rather than keeping it in the
532 process's heap for reallocation. It is also VERY SLOW.
534 config MALLOC_STANDARD
535 bool "malloc-standard"
536 depends on ARCH_USE_MMU
538 "malloc-standard" is derived from the public domain dlmalloc
539 implementation by Doug Lea. It is quite fast, and is pretty smart
540 about reusing already allocated memory, and minimizing memory
541 wastage. This uses brk() for small allocations, while using mmap()
542 for larger allocations. This is the default malloc implementation
545 If unsure, answer "malloc-standard".
549 config MALLOC_GLIBC_COMPAT
550 bool "Malloc returns live pointer for malloc(0)"
553 The behavior of malloc(0) is listed as implementation-defined by
554 SuSv3. Glibc returns a valid pointer to something, while uClibc
555 normally returns NULL. I personally feel glibc's behavior is
556 not particularly safe, and allows buggy applications to hide very
559 When this option is enabled, uClibc will act just like glibc, and
560 return a live pointer when someone calls malloc(0). This pointer
561 provides a malloc'ed area with a size of 1 byte. This feature is
562 mostly useful when dealing with applications using autoconf's broken
563 AC_FUNC_MALLOC macro (which redefines malloc as rpl_malloc if it
564 does not detect glibc style returning-a-valid-pointer-for-malloc(0)
565 behavior). Most people can safely answer N.
567 config UCLIBC_DYNAMIC_ATEXIT
568 bool "Dynamic atexit() Support"
571 When this option is enabled, uClibc will support an infinite number,
572 of atexit() and on_exit() functions, limited only by your available
573 memory. This can be important when uClibc is used with C++, since
574 global destructors are implemented via atexit(), and it is quite
575 possible to exceed the default number when this option is disabled.
576 Enabling this option adds a few bytes, and more significantly makes
577 atexit and on_exit depend on malloc, which can be bad when compiling
580 Unless you use uClibc with C++, you should probably answer N.
583 bool "Old (visible) atexit Support"
586 Enable this option if you want to update from 0.9.28 to git/0.9.29,
587 else you will be missing atexit() until you rebuild all apps.
589 config UCLIBC_SUSV3_LEGACY
590 bool "Enable SuSv3 LEGACY functions"
597 Enable this option if you want to have SuSv3 LEGACY functions
598 in the library, else they are replaced by SuSv3 proposed macros.
599 Currently applies to:
601 bcmp, bcopy, bzero, index, rindex, ftime,
602 bsd_signal, (ecvt), (fcvt), gcvt, (getcontext),
603 (getwd), (makecontext),
604 mktemp, (pthread_attr_getstackaddr), (pthread_attr_setstackaddr),
605 scalb, (setcontext), (swapcontext), ualarm, usleep,
608 WARNING! ABI incompatibility.
610 config UCLIBC_SUSV3_LEGACY_MACROS
611 bool "Enable SuSv3 LEGACY macros"
614 Enable this option if you want to have SuSv3 LEGACY macros.
615 Currently applies to bcopy/bzero/bcmp/index/rindex et al.
616 WARNING! ABI incompatibility.
618 config UCLIBC_SUSV4_LEGACY
619 bool "Enable SuSv4 LEGACY or obsolescent functions"
622 Enable this option if you want to have SuSv4 LEGACY functions
623 and macros in the library.
624 Currently applies to:
627 _longjmp, _setjmp, _tolower, _toupper, ftw, getitimer,
628 gettimeofday, isascii, pthread_getconcurrency,
629 pthread_setconcurrency, setitimer, setpgrp, sighold,
630 sigignore, sigpause, sigrelse, sigset, siginterrupt,
631 tempnam, toascii, ulimit.
634 asctime, asctime_r, ctime, ctime_r, gets, rand_r,
637 WARNING! ABI incompatibility.
639 config UCLIBC_HAS_STUBS
640 bool "Provide stubs for unavailable functionality"
643 With this option uClibc provides non-functional stubs for
644 functions which are impossible to implement on the target
645 architecture. Otherwise, such functions are simply omitted.
647 As of 2008-07, this option makes uClibc provide fork() stub
648 on NOMMU targets. It always sets errno to ENOSYS and returns -1.
650 This may be useful if you port a lot of software and cannot
651 audit all of it and replace or disable fork() usage.
652 With this option, a program which uses fork() will build
653 successfully. Of course, it may be useless if fork()
654 is essential for its operation.
656 config UCLIBC_HAS_SHADOW
657 bool "Shadow Password Support"
660 Answer N if you do not need shadow password support.
661 Most people will answer Y.
663 config UCLIBC_HAS_PROGRAM_INVOCATION_NAME
664 bool "Support for program_invocation_name"
667 Support for the GNU-specific program_invocation_name and
668 program_invocation_short_name strings. Some GNU packages
669 (like tar and coreutils) utilize these for extra useful
670 output, but in general are not required.
672 At startup, these external strings are automatically set
673 up based on the value of ARGV[0].
675 If unsure, just answer N.
677 config UCLIBC_HAS___PROGNAME
678 bool "Support for __progname"
680 depends on UCLIBC_HAS_PROGRAM_INVOCATION_NAME
682 Some packages (like openssh) like to peek into internal libc
683 symbols to make their output a bit more user friendly.
685 At startup, __progname is automatically set up based on the
688 If unsure, just answer N.
690 config UCLIBC_HAS_PTY
691 bool "Support for pseudo-terminals"
694 This enables support for pseudo-terminals (see man 4 pts
697 If unsure, just answer Y.
700 bool "Assume that /dev/pts is a devpts or devfs file system"
702 depends on UCLIBC_HAS_PTY
704 Enable this if /dev/pts is on a devpts or devfs filesystem. Both
705 these filesystems automatically manage permissions on the /dev/pts
706 devices. You may need to mount your devpts or devfs filesystem on
707 /dev/pts for this to work.
709 Most people should answer Y.
711 config UNIX98PTY_ONLY
712 bool "Support only Unix 98 PTYs"
714 depends on UCLIBC_HAS_PTY
716 If you want to support only Unix 98 PTYs enable this. Some older
717 applications may need this disabled and will thus use legacy BSD
718 style PTY handling which is more complex and also bigger than
719 Unix 98 PTY handling.
721 For most current programs, you can generally answer Y.
724 config UCLIBC_HAS_GETPT
725 bool "Support getpt() (glibc-compat)"
727 depends on UCLIBC_HAS_PTY
729 Some packages may need getpt().
730 All of those are non-standard and can be considered
731 GNU/libc compatibility.
732 Either use posix_openpt() or just open /dev/ptmx yourself.
734 If unsure, just say N.
738 # Have to use __libc_ptyname{1,2}[] and related bloat
739 config UCLIBC_HAS_GETPT
743 config UCLIBC_HAS_LIBUTIL
744 bool "Provide libutil library and functions"
745 depends on UCLIBC_HAS_PTY
748 Provide a libutil library.
749 This non-standard conforming library provides the following
752 forkpty(): combines openpty(), fork(2), and login_tty() to
753 create a new process operating in a pseudo-terminal.
754 login(): write utmp and wtmp entries
755 login_tty(): prepares for a login on the tty fd by creating a
756 new session, making fd the controlling terminal for
757 the calling process, setting fd to be the standard
758 input, output, and error streams of the current
759 process, and closing fd.
760 logout(): write utmp and wtmp entries
761 logwtmp(): constructs a utmp structure and calls updwtmp() to
762 append the structure to the utmp file.
763 openpty(): finds an available pseudo-terminal and returns
764 file descriptors for the master and slave
766 This library adds about 3k-4k to your system.
768 config UCLIBC_HAS_TM_EXTENSIONS
769 bool "Support 'struct tm' timezone extension fields"
772 Enabling this option adds fields to 'struct tm' in time.h for
773 tracking the number of seconds east of UTC, and an abbreviation for
774 the current timezone. These fields are not specified by the SuSv3
775 standard, but they are commonly used in both GNU and BSD application
778 To strictly follow the SuSv3 standard, leave this disabled.
779 Most people will probably want to answer Y.
781 config UCLIBC_HAS_TZ_CACHING
782 bool "Enable caching of the last valid timezone 'TZ' string"
785 Answer Y to enable caching of the last valid 'TZ' string describing
786 the timezone setting. This allows a quick string compare to avoid
787 repeated parsing of unchanged 'TZ' strings when tzset() is called.
789 Most people will answer Y.
791 config UCLIBC_HAS_TZ_FILE
792 bool "Enable '/etc/TZ' file support to set a default timezone (uClibc-specific)"
795 Answer Y to enable the setting of a default timezone for uClibc.
797 Ordinarily, uClibc gets the timezone information exclusively from the
798 'TZ' environment variable. In particular, there is no support for
799 the zoneinfo directory tree or the /etc/timezone file used by glibc.
801 With this option enabled, uClibc will use the value stored in the
802 file '/etc/TZ' (default path) to obtain timezone information if the
803 'TZ' environment variable is missing or has an invalid value. The
804 file consists of a single line (newline required) of text describing
805 the timezone in the format specified for the TZ environment variable.
807 Doing 'echo CST6CDT > /etc/TZ' is enough to create a valid file.
809 http://www.opengroup.org/onlinepubs/007904975/basedefs/xbd_chap08.html
810 for details on valid settings of 'TZ'.
812 Most people will answer Y.
814 config UCLIBC_HAS_TZ_FILE_READ_MANY
815 bool "Repeatedly read the '/etc/TZ' file"
816 depends on UCLIBC_HAS_TZ_FILE
819 Answer Y to enable repeated reading of the '/etc/TZ' file even after
820 a valid value has been read. This incurs the overhead of an
821 open/read/close for each tzset() call (explicit or implied). However,
822 setting this will allow applications to update their timezone
823 information if the contents of the file change.
825 Most people will answer Y.
827 config UCLIBC_TZ_FILE_PATH
828 string "Path to the 'TZ' file for setting the global timezone"
829 depends on UCLIBC_HAS_TZ_FILE
832 This is the path to the 'TZ' file.
834 Most people will use the default of '/etc/TZ'.
838 menu "Advanced Library Settings"
840 config UCLIBC_PWD_BUFFER_SIZE
841 int "Buffer size for getpwnam() and friends"
845 This sets the value of the buffer size for getpwnam() and friends.
846 By default, this is 256. (For reference, glibc uses 1024).
847 The value can be found using sysconf() with the _SC_GETPW_R_SIZE_MAX
850 config UCLIBC_GRP_BUFFER_SIZE
851 int "Buffer size for getgrnam() and friends"
855 This sets the value of the buffer size for getgrnam() and friends.
856 By default, this is 256. (For reference, glibc uses 1024).
857 The value can be found using sysconf() with the _SC_GETGR_R_SIZE_MAX
860 comment "Support various families of functions"
862 config UCLIBC_LINUX_MODULE_24
863 bool "Linux kernel module functions"
864 default !(TARGET_bfin)
866 create_module, query_module
867 are used in linux (prior to 2.6) for loadable kernel modules.
869 Say N if you do not use kernel modules, or you only support
872 config UCLIBC_LINUX_SPECIFIC
873 bool "Linux specific functions"
876 capget(), capset(), fstatfs(), inotify_*(), ioperm(), iopl(),
877 madvise(), modify_ldt(), personality(), prctl()/arch_prctl(),
878 ppoll(), readahead(), reboot(), remap_file_pages(),
879 sched_getaffinity(), sched_setaffinity(), sendfile(),
880 setfsgid(), setfsuid(), setresuid(),
881 splice(), vmsplice(), tee(), signalfd(), swapoff(), swapon(),
882 sync_file_range(), sysctl(), sysinfo(), vhangup()
884 config UCLIBC_HAS_GNU_ERROR
885 bool "Support GNU extensions for error-reporting"
888 Support for the GNU-specific error(), error_at_line(),
889 void (* error_print_progname)(), error_message_count
890 functions and variables. Some GNU packages
891 utilize these for extra useful output, but in general
894 If unsure, just answer N.
896 config UCLIBC_BSD_SPECIFIC
897 bool "BSD specific functions"
900 mincore(), getdomainname(), setdomainname()
904 config UCLIBC_HAS_BSD_ERR
905 bool "BSD err functions"
908 These functions are non-standard BSD extensions.
909 err(), errx(), warn(), warnx(), verr(), verrx(), vwarn(), vwarnx()
913 config UCLIBC_HAS_OBSOLETE_BSD_SIGNAL
914 bool "BSD obsolete signal functions"
917 These functions are provided as a compatibility interface for
918 programs that make use of the historical System V signal API.
919 This API is obsolete:
920 new applications should use the POSIX signal API (sigaction(2),
921 sigprocmask(2), etc.).
924 sigset(), sighold(), sigrelse(), sigignore()
928 config UCLIBC_HAS_OBSOLETE_SYSV_SIGNAL
929 bool "SYSV obsolete signal functions"
932 Use of sysv_signal() should be avoided; use sigaction(2) instead.
936 config UCLIBC_NTP_LEGACY
937 bool "ntp_*() aliases"
940 Provide legacy aliases for ntp functions:
941 ntp_adjtime(), ntp_gettime()
943 It is safe to say N here.
945 config UCLIBC_SV4_DEPRECATED
946 bool "Enable SVr4 deprecated functions"
949 These functions are DEPRECATED in System V release 4.
950 Say N unless you desparately need one of the functions below:
952 ustat() [use statfs(2) in your code instead]
954 config UCLIBC_HAS_REALTIME
955 bool "Realtime-related family of SUSv functions"
958 These functions are part of the Timers option and need not
959 be available on all implementations.
960 Includes AIO, message-queue, scheduler, semaphore functions:
975 clock_getres(), clock_gettime(), clock_settime()
977 mlockall(), munlockall()
989 sched_get_priority_max(), sched_get_priority_min()
991 sched_rr_get_interval()
1000 sem_trywait(), sem_wait()
1003 sigtimedwait(), sigwaitinfo()
1006 timer_getoverrun(), timer_gettime(), timer_settime()
1008 config UCLIBC_HAS_ADVANCED_REALTIME
1009 bool "Advanced realtime-related family of SUSv functions"
1011 depends on UCLIBC_HAS_REALTIME
1013 These functions are part of the Timers option and need not
1014 be available on all implementations.
1016 clock_getcpuclockid()
1025 posix_spawnattr_destroy(), posix_spawnattr_init()
1026 posix_spawnattr_getflags(), posix_spawnattr_setflags()
1027 posix_spawnattr_getpgroup(), posix_spawnattr_setpgroup()
1028 posix_spawnattr_getschedparam(), posix_spawnattr_setschedparam()
1029 posix_spawnattr_getschedpolicy(), posix_spawnattr_setschedpolicy()
1030 posix_spawnattr_getsigdefault(), posix_spawnattr_setsigdefault()
1031 posix_spawnattr_getsigmask(), posix_spawnattr_setsigmask()
1032 posix_spawn_file_actions_addclose()
1033 posix_spawn_file_actions_adddup2()
1034 posix_spawn_file_actions_addopen()
1035 posix_spawn_file_actions_destroy()
1036 posix_spawn_file_actions_init()
1039 posix_typed_mem_get_info()
1040 pthread_mutex_timedlock()
1043 #config UCLIBC_HAS_TERMIOS
1044 # bool "termios functions"
1047 # Get and set terminal attributes, line control, get and set baud
1049 # termios(), tcgetattr(), tcsetattr(), tcsendbreak(), tcdrain(),
1050 # tcflush(), tcflow(), cfmakeraw(), cfgetospeed(), cfgetispeed(),
1051 # cfsetispeed(), cfsetospeed(), cfsetspeed()
1055 config UCLIBC_HAS_EPOLL
1059 epoll_create(), epoll_ctl(), epoll_wait() functions.
1061 config UCLIBC_HAS_XATTR
1062 bool "Extended Attributes"
1065 Extended Attributes support.
1080 Say N unless you need support for extended attributes and the
1081 filesystems do actually support them.
1083 config UCLIBC_HAS_PROFILING
1084 bool "Profiling support"
1087 gcc's -finstrument-functions needs these.
1089 Most people can safely answer N.
1091 config UCLIBC_HAS_CRYPT_IMPL
1092 bool "libcrypt support"
1095 libcrypt contains crypt(), setkey() and encrypt()
1097 config UCLIBC_HAS_CRYPT_STUB
1098 bool "libcrypt stubs"
1100 depends on !UCLIBC_HAS_CRYPT_IMPL
1102 Standards mandate that crypt(3) provides a stub if it is unavailable.
1103 If you enable this option then stubs for
1104 crypt(), setkey() and encrypt()
1105 will be provided in a small libcrypt.
1107 config UCLIBC_HAS_CRYPT
1109 depends on UCLIBC_HAS_CRYPT_IMPL || UCLIBC_HAS_CRYPT_STUB
1112 menuconfig UCLIBC_HAS_NETWORK_SUPPORT
1113 bool "Networking Support"
1116 Say N here if you do not need network support.
1118 if UCLIBC_HAS_NETWORK_SUPPORT
1119 config UCLIBC_HAS_SOCKET
1120 bool "Socket support"
1123 If you want to include support for sockets then answer Y.
1125 config UCLIBC_HAS_IPV4
1126 bool "IP version 4 support"
1128 select UCLIBC_HAS_SOCKET
1130 If you want to include support for the Internet Protocol
1131 (IP version 4) then answer Y.
1133 Most people will say Y.
1135 config UCLIBC_HAS_IPV6
1136 bool "IP version 6 support"
1138 select UCLIBC_HAS_SOCKET
1140 If you want to include support for the next version of the Internet
1141 Protocol (IP version 6) then answer Y.
1143 Most people should answer N.
1145 config UCLIBC_HAS_RPC
1146 bool "Remote Procedure Call (RPC) support"
1148 # RPC+socket-ipvX doesn't currently work.
1149 depends on UCLIBC_HAS_IPV4 || UCLIBC_HAS_IPV6
1151 If you want to include RPC support, enable this. RPC is rarely used
1152 for anything except for the NFS filesystem. Unless you plan to use
1153 NFS, you can probably leave this set to N and save some space.
1155 If you need to use NFS then you should answer Y.
1157 config UCLIBC_HAS_FULL_RPC
1158 bool "Full RPC support"
1159 depends on UCLIBC_HAS_RPC
1160 default y if !HAVE_SHARED
1162 Normally we enable just enough RPC support for things like rshd and
1163 nfs mounts to work. If you find you need the rest of the RPC stuff,
1164 then enable this option. Most people can safely answer N.
1166 config UCLIBC_HAS_REENTRANT_RPC
1167 bool "Reentrant RPC support"
1168 depends on UCLIBC_HAS_RPC
1169 default y if !HAVE_SHARED
1171 Most packages utilize the normal (non-reentrant) RPC functions, but
1172 some (like exportfs from nfs-utils) need these reentrant versions.
1174 Most people can safely answer N.
1176 config UCLIBC_USE_NETLINK
1177 bool "Use netlink to query interfaces"
1179 depends on UCLIBC_HAS_SOCKET
1181 In newer versions of Linux (2.4.17+), support was added for querying
1182 network device information via netlink rather than the old style
1183 ioctl's. Most of the time, the older ioctl style is sufficient (and
1184 it is smaller than netlink), but if you find that not all of your
1185 devices are being returned by the if_nameindex() function, you will
1186 have to use the netlink implementation.
1188 Most people can safely answer N.
1190 config UCLIBC_SUPPORT_AI_ADDRCONFIG
1191 bool "Support the AI_ADDRCONFIG flag"
1192 depends on UCLIBC_USE_NETLINK
1195 The implementation of AI_ADDRCONFIG is aligned with the glibc
1196 implementation using netlink to query interfaces to find both
1197 ipv4 and ipv6 support. This is only needed if an application uses
1198 the AI_ADDRCONFIG flag.
1200 Most people can safely answer N.
1202 config UCLIBC_HAS_BSD_RES_CLOSE
1203 bool "Support res_close() (bsd-compat)"
1206 Answer Y if you desperately want to support BSD compatibility in
1209 Most people will say N.
1211 config UCLIBC_HAS_COMPAT_RES_STATE
1212 bool "Use compatible but bloated _res"
1215 Answer Y if you build network utilities and they muck with resolver
1216 internals a lot (_res global structure). uclibc does not use most
1217 of _res.XXX fields, and with this option OFF they won't even exist.
1218 Which will make e.g. dig build fail.
1219 Answering N saves around 400 bytes in bss.
1221 config UCLIBC_HAS_EXTRA_COMPAT_RES_STATE
1222 bool "Use extra compatible but extra bloated _res"
1225 Answer Y if selecting UCLIBC_HAS_COMPAT_RES_STATE is not enough.
1226 As far as I can say, this should never be needed.
1228 config UCLIBC_HAS_LIBRESOLV_STUB
1229 bool "Provide libresolv stub"
1232 Provide a dummy resolv library.
1234 config UCLIBC_HAS_LIBNSL_STUB
1235 bool "Provide libnsl stub"
1238 Provide a dummy nsl library.
1243 menu "String and Stdio Support"
1245 config UCLIBC_HAS_STRING_GENERIC_OPT
1246 bool "Use faster (but larger) generic string functions"
1249 Answer Y to use the (tweaked) glibc generic string functions.
1251 In general, they are faster (but 3-5K larger) than the base
1252 uClibc string functions which are optimized solely for size.
1254 Many people will answer Y.
1256 config UCLIBC_HAS_STRING_ARCH_OPT
1257 bool "Use arch-specific assembly string functions (where available)"
1260 Answer Y to use any archtecture-specific assembly language string
1261 functions available for this target plaform.
1263 Note that assembly implementations are not available for all string
1264 functions, so some generic (written in C) string functions may
1267 These are small and fast, the only reason _not_ to say Y here is
1268 for debugging purposes.
1270 config UCLIBC_HAS_CTYPE_TABLES
1271 bool "Use Table Versions Of 'ctype.h' Functions."
1274 Answer Y to use table versions of the 'ctype.h' functions.
1275 While the non-table versions are often smaller when building
1276 statically linked apps, they work only in stub locale mode.
1278 Most people will answer Y.
1280 config UCLIBC_HAS_CTYPE_SIGNED
1281 bool "Support Signed Characters In 'ctype.h' Functions."
1282 depends on UCLIBC_HAS_CTYPE_TABLES
1285 Answer Y to enable support for passing signed char values to
1286 the 'ctype.h' functions. ANSI/ISO C99 and SUSv3 specify that
1287 these functions are only defined for unsigned char values and
1288 EOF. However, glibc allows negative signed char values as well
1289 in order to support 'broken old programs'.
1291 Most people will answer Y.
1294 prompt "ctype argument checking"
1295 depends on UCLIBC_HAS_CTYPE_TABLES
1296 default UCLIBC_HAS_CTYPE_UNSAFE
1298 Please select the invalid arg behavior you want for the 'ctype'
1301 The 'ctype' functions are now implemented using table lookups, with
1302 the arg being the index. This can result in incorrect memory accesses
1303 or even segfaults for args outside of the allowed range.
1305 NOTE: This only affects the 'ctype' _functions_. It does not affect
1306 the macro implementations.
1308 config UCLIBC_HAS_CTYPE_UNSAFE
1309 bool "Do not check -- unsafe"
1311 config UCLIBC_HAS_CTYPE_CHECKED
1312 bool "Detect and handle appropriately"
1314 config UCLIBC_HAS_CTYPE_ENFORCED
1315 bool "Issue a diagnostic and abort()"
1320 config UCLIBC_HAS_WCHAR
1321 bool "Wide Character Support"
1324 Answer Y to enable wide character support. This will make uClibc
1325 much larger. It is also currently required for locale support.
1327 Most people will answer N.
1329 config UCLIBC_HAS_LOCALE
1330 bool "Locale Support"
1331 select UCLIBC_HAS_WCHAR
1332 select UCLIBC_HAS_CTYPE_TABLES
1335 uClibc now has full ANSI/ISO C99 locale support (except for
1336 wcsftime() and collating items in regex). Be aware that enabling
1337 this option will make uClibc much larger.
1339 Enabling UCLIBC_HAS_LOCALE with the default set of supported locales
1340 (169 UTF-8 locales, and 144 locales for other codesets) will enlarge
1341 uClibc by around 300k. You can reduce this size by building your own
1342 custom set of locate data (see extra/locale/LOCALES for details).
1344 uClibc's locale support is still under development. For example,
1345 codesets using shift states are not currently supported. Support is
1346 planned in the next iteration of locale support.
1348 Answer Y to enable locale support. Most people will answer N.
1352 prompt "Locale data"
1353 depends on UCLIBC_HAS_LOCALE
1354 default UCLIBC_BUILD_ALL_LOCALE
1356 config UCLIBC_BUILD_ALL_LOCALE
1358 depends on UCLIBC_HAS_LOCALE
1360 This builds all the locales that are available on your
1363 config UCLIBC_BUILD_MINIMAL_LOCALE
1364 bool "Only selected locales"
1365 depends on UCLIBC_HAS_LOCALE
1367 If you do not need all locales that are available on your
1368 host-box, then set this to 'Y'.
1370 config UCLIBC_PREGENERATED_LOCALE_DATA
1371 bool "Use Pre-generated Locale Data"
1372 depends on UCLIBC_HAS_LOCALE
1374 Use pre-built locale data.
1376 Note that these pregenerated locales are sensitive to your
1377 target architecture (endianess, bitcount).
1379 Saying N here is highly recommended.
1383 config UCLIBC_BUILD_MINIMAL_LOCALES
1384 string "locales to use"
1385 depends on UCLIBC_BUILD_MINIMAL_LOCALE
1388 Space separated list of locales to use.
1395 config UCLIBC_DOWNLOAD_PREGENERATED_LOCALE_DATA
1396 bool "Automagically Download the Pre-generated Locale Data (if necessary)"
1397 depends on UCLIBC_PREGENERATED_LOCALE_DATA
1400 If you would like the build process to use 'wget' to automatically
1401 download the pregenerated locale data, enable this option. Otherwise
1402 you will need to obtain the locale data yourself from:
1403 http://www.uclibc.org/downloads/uClibc-locale-*.tgz
1404 and place the uClibc-locale-*.tgz tarball in the extra/locale/
1407 Note that the use of pregenerated locale data is discouraged.
1409 config UCLIBC_HAS_XLOCALE
1410 bool "Extended Locale Support (experimental/incomplete)"
1411 depends on UCLIBC_HAS_LOCALE
1414 Answer Y to enable extended locale support similar to that provided
1415 by glibc. This is primarily intended to support libstd++
1417 However, it also allows thread-specific locale selection via
1420 Most people will answer N.
1422 config UCLIBC_HAS_HEXADECIMAL_FLOATS
1423 bool "Support hexadecimal float notation"
1424 depends on UCLIBC_HAS_CTYPE_TABLES
1425 depends on UCLIBC_HAS_FLOATS
1428 Answer Y to enable support for hexadecimal float notation in the
1429 (wchar and) char string to floating point conversion functions, as
1430 well as support for the %a and %A conversion specifiers in the
1431 *printf() and *scanf() functions.
1433 Most people will answer N.
1435 config UCLIBC_HAS_GLIBC_DIGIT_GROUPING
1436 bool "Support glibc's \"'\" flag for allowing locale-specific digit grouping"
1437 depends on UCLIBC_HAS_LOCALE
1438 depends on UCLIBC_HAS_FLOATS
1441 Answer Y to enable support for glibc's \"'\" flag for allowing
1442 locale-specific digit grouping in base 10 integer conversions and
1443 appropriate floating point conversions in the *printf() and *scanf()
1446 Most people will answer N.
1448 config UCLIBC_HAS_SCANF_LENIENT_DIGIT_GROUPING
1449 bool "Do not require digit grouping when the \"'\" flag is specified"
1450 depends on UCLIBC_HAS_GLIBC_DIGIT_GROUPING
1453 Answer Y to make digit grouping optional when the \"'\" flag is
1455 This is the standard glibc behavior. If the initial string of digits
1456 exceeds the maximum group number, the input will be treated as a
1457 normal non-grouped number.
1459 Most people will answer N.
1461 config UCLIBC_HAS_GLIBC_CUSTOM_PRINTF
1462 bool "Support glibc's register_printf_function() (glibc-compat)"
1463 depends on !USE_OLD_VFPRINTF
1466 Answer Y to support glibc's register_printf_function() to allow an
1467 application to add its own printf conversion specifiers.
1469 NOTE: Limits the number or registered specifiers to 10.
1470 NOTE: Requires new conversion specifiers to be ASCII
1471 characters (0-0x7f). This is to avoid problems with processing
1472 format strings in locales with different multibyte conversions.
1474 Most people will answer N.
1476 config USE_OLD_VFPRINTF
1477 bool "Use the old vfprintf implementation"
1478 depends on !UCLIBC_HAS_WCHAR
1481 Set to true to use the old vfprintf instead of the new. This is
1482 roughly C89 compliant with some extensions, and is much smaller.
1483 However, it does not support wide chars, positional args, or glibc
1484 custom printf specifiers.
1486 Most people will answer N.
1488 config UCLIBC_PRINTF_SCANF_POSITIONAL_ARGS
1489 int "Maximum number of positional args. Either 0 or >= 9."
1490 depends on !USE_OLD_VFPRINTF
1493 Set the maximum number of positional args supported by the
1494 printf/scanf functions. The Single Unix Specification Version 3
1495 requires a minimum value of 9. Setting this to a value lower than
1496 9 will disable positional arg support and cause the NL_ARGMAX macro
1497 in limits.h to be #undef'd.
1499 WARNING! The workspace to support positional args is currently
1500 allocated on the stack. You probably don't want to set
1501 this to too high a value.
1503 Most people will answer 9.
1506 config UCLIBC_HAS_SCANF_GLIBC_A_FLAG
1507 bool "Support glibc's 'a' flag for scanf string conversions (not implemented)"
1510 NOTE!!! Currently Not Implemented!!! Just A Place Holder!! NOTE!!!
1511 NOTE!!! Conflicts with an ANSI/ISO C99 scanf flag!! NOTE!!!
1513 Answer Y to enable support for glibc's 'a' flag for the scanf string
1514 conversions '%s', '%[', '%ls', '%l[', and '%S'. This is used to
1515 auto-allocate sufficient memory to hold the data retrieved.
1517 Most people will answer N.
1520 prompt "Stdio buffer size"
1521 default UCLIBC_HAS_STDIO_BUFSIZ_4096
1523 Please select a value for BUFSIZ. This will be used by the
1524 stdio subsystem as the default buffer size for a file, and
1525 affects fopen(), setvbuf(), etc.
1527 NOTE: Setting this to 'none' will disable buffering completely.
1528 However, BUFSIZ will still be defined in stdio.h as 256 because
1529 many applications use this value.
1531 config UCLIBC_HAS_STDIO_BUFSIZ_NONE
1532 bool "none (WARNING - BUFSIZ will be 256 in stdio.h)"
1533 depends on !UCLIBC_HAS_WCHAR
1535 config UCLIBC_HAS_STDIO_BUFSIZ_256
1536 bool "256 (minimum ANSI/ISO C99 value)"
1538 config UCLIBC_HAS_STDIO_BUFSIZ_512
1541 config UCLIBC_HAS_STDIO_BUFSIZ_1024
1544 config UCLIBC_HAS_STDIO_BUFSIZ_2048
1547 config UCLIBC_HAS_STDIO_BUFSIZ_4096
1550 config UCLIBC_HAS_STDIO_BUFSIZ_8192
1553 # If you add more choices, you will need to update uClibc_stdio.h.
1558 prompt "Stdio builtin buffer size (uClibc-specific)"
1559 depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
1560 default UCLIBC_HAS_STDIO_BUILTIN_BUFFER_NONE
1562 When a FILE is created with fopen(), an attempt is made to allocate
1563 a BUFSIZ buffer for it. If the allocation fails, fopen() will still
1564 succeed but the FILE will be unbuffered.
1566 This option adds a small amount of space to each FILE to act as an
1567 emergency buffer in the event of a buffer allocation failure.
1569 Most people will answer None.
1571 config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_NONE
1574 config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_4
1577 config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_8
1580 # If you add more choices, you will need to update uClibc_stdio.h.
1584 config UCLIBC_HAS_STDIO_SHUTDOWN_ON_ABORT
1585 bool "Attempt to shutdown stdio subsystem when abort() is called."
1588 ANSI/ISO C99 requires abort() to be asyn-signal-safe. So there was
1589 a behavioral change made in SUSv3. Previously, abort() was required
1590 to have the affect of fclose() on all open streams. The wording has
1591 been changed to "may" from "shall".
1593 Most people will answer N.
1595 config UCLIBC_HAS_STDIO_GETC_MACRO
1596 bool "Provide a macro version of getc()"
1597 depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
1600 Provide a macro version of getc().
1602 Most people will answer Y.
1604 config UCLIBC_HAS_STDIO_PUTC_MACRO
1605 bool "Provide a macro version of putc()"
1606 depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
1609 Provide a macro version of putc().
1611 Most people will answer Y.
1613 config UCLIBC_HAS_STDIO_AUTO_RW_TRANSITION
1614 bool "Support auto-r/w transition"
1617 Answer Y to enable the stdio subsystem to automaticly transition
1618 between reading and writing. This relaxes the ANSI/ISO C99
1621 When a file is opened with update mode ('+' as the second or third
1622 character in the list of mode argument values), both input and output
1623 may be performed on the associated stream. However, output shall not
1624 be directly followed by input without an intervening call to the
1625 fflush function or to a file positioning function (fseek, fsetpos,
1626 or rewind), and input shall not be directly followed by output without
1627 an intervening call to a file positioning function, unless the input
1628 operation encounters endÂofÂfile.
1630 Most people will answer Y.
1632 config UCLIBC_HAS_FOPEN_LARGEFILE_MODE
1633 bool "Support an fopen() 'F' flag for large file mode (uClibc-specific)"
1634 depends on UCLIBC_HAS_LFS
1637 Answer Y to enable a uClibc-specific extension to allow passing an
1638 additional 'F' flag in the mode string for fopen() to specify that
1639 the file should be open()ed with the O_LARGEFILE flag set.
1641 Most people will answer N.
1643 config UCLIBC_HAS_FOPEN_EXCLUSIVE_MODE
1644 bool "Support an fopen() 'x' flag for exclusive mode (glibc-compat)"
1647 Answer Y to support a glibc extension to allow passing
1648 additional 'x' flag in the mode string for fopen() to specify that
1649 the file should be open()ed with the O_EXCL flag set.
1651 Most people will answer N.
1653 config UCLIBC_HAS_GLIBC_CUSTOM_STREAMS
1654 bool "Support fmemopen(), open_memstream(), and fopencookie() (glibc-compat)"
1657 Answer Y to support the glibc 'custom stream' extension functions
1658 fmemopen(), open_memstream(), and fopencookie().
1660 NOTE: There are some minor differences regarding seeking behavior.
1662 Most people will answer N.
1664 config UCLIBC_HAS_PRINTF_M_SPEC
1665 bool "Support the '%m' specifier in printf format strings (glibc-compat)"
1668 Answer Y to support a glibc extension to interpret '%m' in printf
1669 format strings as an instruction to output the error message string
1670 (as generated by strerror) corresponding to the current value of
1673 Most people will answer N.
1675 config UCLIBC_HAS_ERRNO_MESSAGES
1676 bool "Include the errno message text in the library"
1679 Answer Y if you want to include the errno message text in the
1680 library. This adds about 3K to the library, but enables strerror()
1681 to generate text other than 'Unknown error <number>'.
1683 Most people will answer Y.
1685 config UCLIBC_HAS_SYS_ERRLIST
1686 bool "Support sys_errlist[] (obsolete-compat)"
1687 depends on UCLIBC_HAS_ERRNO_MESSAGES
1690 Answer Y if you want to support the obsolete sys_errlist[].
1691 This adds about 0.5k to the library, except for the mips
1692 arch where it adds over 4K.
1694 WARNING! In the future, support for sys_errlist[] may be unavailable
1695 in at least some configurations. In fact, it may be removed
1698 Most people will answer N.
1700 Application writers: use the strerror(3) function.
1702 config UCLIBC_HAS_SIGNUM_MESSAGES
1703 bool "Include the signum message text in the library"
1706 Answer Y if you want to include the signum message text in the
1707 library. This adds about 0.5K to the library, but enables strsignal()
1708 to generate text other than 'Unknown signal <number>'.
1710 Most people will answer Y.
1712 config UCLIBC_HAS_SYS_SIGLIST
1713 bool "Support sys_siglist[] (bsd-compat)"
1714 depends on UCLIBC_HAS_SIGNUM_MESSAGES
1717 Answer Y if you want to support sys_siglist[].
1719 WARNING! In the future, support for sys_siglist[] may be unavailable
1720 in at least some configurations. In fact, it may be removed
1723 Most people will answer N.
1725 config UCLIBC_HAS_GETTEXT_AWARENESS
1726 bool "Include gettext awareness"
1727 depends on UCLIBC_HAS_LOCALE && UCLIBC_MJN3_ONLY
1730 NOTE!!! Not yet integrated with strerror and strsignal. NOTE!!!
1732 Answer Y if you want to include weak stub gettext support and
1733 make the *strerror*() and strsignal() functions gettext-aware.
1735 Currently, to get functional gettext functionality you will need
1738 Most people will answer N.
1740 config UCLIBC_HAS_GNU_GETOPT
1741 bool "Support gnu getopt"
1744 Answer Y if you want to include full gnu getopt() instead of a
1745 (much smaller) SUSv3 compatible getopt().
1747 Most people will answer Y.
1749 config UCLIBC_HAS_STDIO_FUTEXES
1750 bool "Use futexes for multithreaded I/O locking"
1752 depends on UCLIBC_HAS_THREADS_NATIVE
1754 If you want to compile uClibc to use futexes for low-level
1755 I/O locking, answer Y. Otherwise, answer N.
1757 config UCLIBC_HAS_GETOPT_LONG
1758 bool "Support getopt_long/getopt_long_only"
1759 depends on !UCLIBC_HAS_GNU_GETOPT
1762 Answer Y if you want to include getopt_long[_only() used by many
1765 Most people will answer Y.
1767 config UCLIBC_HAS_GNU_GETSUBOPT
1768 bool "Support glibc getsubopt"
1771 Answer Y if you want to include glibc getsubopt() instead of a
1772 smaller SUSv3 compatible getsubopt().
1774 Most people will answer Y.
1780 config UCLIBC_HAS_REGEX
1781 bool "Regular Expression Support"
1784 POSIX regular expression code is really big -- 53k all by itself.
1785 If you don't use regular expressions, turn this off and save space.
1786 Of course, if you only statically link, leave this on, since it will
1787 only be included in your apps if you use regular expressions.
1789 config UCLIBC_HAS_REGEX_OLD
1790 bool "Use the older (stable) regular expression code"
1791 depends on UCLIBC_HAS_REGEX
1794 There are two versions of regex. The older (stable) version has
1795 been in uClibc for quite a long time but hasn't seen too many
1796 updates. It also has some known issues when dealing with uncommon
1797 corner cases and multibyte/unicode strings. However, it is quite
1798 a bit smaller than the newer version.
1800 If the older version has worked for you and you don't need unicode
1801 support, then stick with the old version (and say Y here).
1802 Otherwise, you should use the new version (and say N here).
1804 config UCLIBC_HAS_FNMATCH
1805 bool "fnmatch Support"
1810 config UCLIBC_HAS_FNMATCH_OLD
1811 bool "Use the older (stable) fnmatch code"
1812 depends on UCLIBC_HAS_FNMATCH
1815 There are two versions of fnmatch. The older (stable) version has
1816 been in uClibc for quite a long time but hasn't seen too many
1817 updates. It also has some known issues when dealing with uncommon
1818 corner cases and multibyte/unicode strings. However, it is quite
1819 a bit smaller than the newer version.
1821 If the older version has worked for you and you don't need unicode
1822 support, then stick with the old version (and say Y here).
1823 Otherwise, you should use the new version (and say N here).
1825 config UCLIBC_HAS_WORDEXP
1826 bool "Support the wordexp() interface"
1827 depends on UCLIBC_HAS_GLOB
1830 The SuSv3 wordexp() interface performs word expansions per the Shell
1831 and Utilities volume of IEEE Std 1003.1-2001, Section 2.6. It is
1832 intended for use by applications that want to implement all of the
1833 standard Bourne shell expansions on input data.
1835 This interface is rarely used, and very large. Unless you have a
1836 pressing need for wordexp(), you should probably answer N.
1838 config UCLIBC_HAS_NFTW
1839 bool "Support the nftw() interface"
1842 The SuSv3 nftw() interface is used to recursively descend
1843 directory paths while repeatedly calling a function.
1845 This interface is rarely used, and adds around 4.5k. Unless you have
1846 a pressing need for nftw(), you should probably answer N.
1848 config UCLIBC_HAS_FTW
1849 bool "Support the ftw() interface"
1851 depends on UCLIBC_SUSV4_LEGACY
1853 The SuSv3 ftw() interface is used to recursively descend
1854 directory paths while repeatedly calling a function.
1856 This interface is rarely used, and adds around 4.5k. Unless you have
1857 a pressing need for ftw(), you should probably answer N.
1860 config UCLIBC_HAS_GLOB
1861 bool "Support the glob() interface"
1862 depends on UCLIBC_HAS_FNMATCH
1866 The glob interface is somewhat large (weighing in at about 2,5k). It
1867 is used fairly often, but is an option since people wanting to go for
1868 absolute minimum size may wish to omit it.
1870 Most people will answer Y.
1872 config UCLIBC_HAS_GNU_GLOB
1873 bool "Support gnu glob() interface"
1874 depends on UCLIBC_HAS_GLOB
1877 The gnu glob interface is somewhat larger (weighing in at about 4,2k)
1878 than it's SuSv3 counterpart (and is out of date). It is an old copy
1879 from glibc and does not support all the GNU specific options.
1881 Answer Y if you want to include full gnu glob() instead of the smaller
1882 SUSv3 compatible glob().
1884 Most people will answer N.
1891 menu "Library Installation Options"
1893 config RUNTIME_PREFIX
1894 string "uClibc runtime library directory"
1895 default "/usr/$(TARGET_ARCH)-linux-uclibc/"
1897 RUNTIME_PREFIX is the directory into which the uClibc runtime
1898 libraries will be installed. The result will look something
1901 lib/ <contains all runtime libraries>
1902 usr/bin/ldd <the ldd utility program>
1903 sbin/ldconfig <the ldconfig utility program>
1904 This value is used by the 'make install' Makefile target. Since this
1905 directory is compiled into the shared library loader, you will need to
1906 recompile uClibc if you change this value...
1908 For a typical target system this should be set to "/", such that
1909 'make install' will install /lib/libuClibc-<VERSION>.so
1912 string "uClibc development environment directory"
1913 default "/usr/$(TARGET_ARCH)-linux-uclibc/usr/"
1915 DEVEL_PREFIX is the directory into which the uClibc development
1916 environment will be installed. The result will look something
1919 lib/ <contains static libs>
1920 include/ <Where all the header files go>
1921 This value is used by the 'make install' Makefile target when
1922 installing a uClibc development environment.
1924 For a typical target system this should be set to "/usr", such that
1925 'make install' will install /usr/include/<header files>.
1928 string "library path component"
1931 Path component where libraries reside.
1933 For a typical target system this should be set to "lib", such that
1934 'make install' will install libraries to "/lib" and "/usr/lib"
1936 DEVEL_PREFIX/MULTILIB_DIR
1937 RUNTIME_PREFIX/MULTILIB_DIR
1939 Other settings may include "lib32" or "lib64".
1941 config HARDWIRED_ABSPATH
1942 bool "Hardwire absolute paths into linker scripts"
1945 This prepends absolute paths to the libraries mentioned in linker
1946 scripts such as libc.so.
1948 This is a build time optimization. It has no impact on dynamic
1949 linking at runtime, which doesn't use linker scripts.
1951 You must disable this to use uClibc with old non-sysroot toolchains,
1952 such as the prebuilt binary cross compilers at:
1953 http://uclibc.org/downloads/binaries
1955 The amount of time saved by this optimization is actually too small to
1956 measure. The linker just had to search the library path to find the
1957 linker script, so the dentries are cache hot if it has to search the
1958 same path again. But it's what glibc does, so we do it too.
1963 menu "Security options"
1965 config UCLIBC_BUILD_PIE
1966 bool "Build utilities as ET_DYN/PIE executables"
1967 depends on HAVE_SHARED
1968 depends on TARGET_arm || TARGET_frv || TARGET_i386 || TARGET_mips || TARGET_powerpc
1969 select FORCE_SHAREABLE_TEXT_SEGMENTS
1972 If you answer Y here, ldd and iconv are built as ET_DYN/PIE
1975 It requires gcc-3.4 and binutils-2.15 (for arm 2.16) or later.
1976 More about ET_DYN/PIE binaries on <http://pax.grsecurity.net/> .
1978 WARNING: This option also enables FORCE_SHAREABLE_TEXT_SEGMENTS, so
1979 all libraries have to be built with -fPIC or -fpic, and all
1980 assembler functions must be written as position independent
1983 config UCLIBC_HAS_ARC4RANDOM
1984 bool "Include the arc4random() function"
1987 Answer Y to support the OpenBSD-like arc4random() function. This
1988 function picks a random number between 0 and N, and will always return
1989 something even if the random driver is dead. If urandom fails then
1990 gettimeofday(2) will be used as the random seed. This function is
1991 designed to be more dependable than invoking /dev/urandom directly.
1992 OpenSSL and OpenNTPD currently support this function.
1994 Most people will answer N.
2000 config UCLIBC_HAS_SSP
2001 bool "Support for GCC stack smashing protector"
2002 depends on !HAVE_NO_SSP
2005 Add code to support GCC's -fstack-protector[-all] option to uClibc.
2006 This requires GCC 4.1 or newer. GCC does not have to provide libssp,
2007 the needed functions are added to ldso/libc instead.
2009 GCC's stack protector is a reimplementation of IBM's propolice.
2010 See http://www.trl.ibm.com/projects/security/ssp/ and
2011 http://www.linuxfromscratch.org/hints/downloads/files/ssp.txt
2014 Note that NOEXECSTACK on a kernel with address space randomization
2015 is generally sufficient to prevent most buffer overflow exploits
2016 without increasing code size. This option essentially adds debugging
2019 Most people will answer N.
2021 config UCLIBC_HAS_SSP_COMPAT
2022 bool "Support for gcc-3.x propolice smashing stack protector"
2023 depends on UCLIBC_HAS_SSP
2026 Add gcc-3.x propolice smashing stack protector to the library.
2028 This requires a patched version of GCC, supporting the
2029 -fstack-protector[-all] options, with the __guard and
2030 __stack_smash_handler functions removed from libgcc.
2031 These functions are added to ldso/libc instead.
2033 More information at:
2034 <http://www.research.ibm.com/trl/projects/security/ssp/>
2036 Most people will answer N.
2038 config SSP_QUICK_CANARY
2039 bool "Use simple guard values without accessing /dev/urandom"
2040 depends on UCLIBC_HAS_SSP
2043 Use gettimeofday(2) to define the __guard without accessing
2045 WARNING: This makes smashing stack protector vulnerable to timing
2047 Most people will answer N.
2050 prompt "Propolice protection blocking signal"
2051 depends on UCLIBC_HAS_SSP
2052 default PROPOLICE_BLOCK_ABRT if ! DODEBUG
2053 default PROPOLICE_BLOCK_SEGV if DODEBUG
2055 "abort" use SIGABRT to block offending programs.
2056 This is the default implementation.
2058 "segfault" use SIGSEGV to block offending programs.
2059 Use this for debugging.
2061 If unsure, answer "abort".
2063 config PROPOLICE_BLOCK_ABRT
2066 config PROPOLICE_BLOCK_SEGV
2071 config UCLIBC_BUILD_SSP
2072 bool "Build uClibc with -fstack-protector"
2073 depends on UCLIBC_HAS_SSP
2076 Build all uClibc libraries and executables with -fstack-protector,
2077 adding extra stack overflow checking to most uClibc functions.
2079 config UCLIBC_BUILD_RELRO
2080 bool "Build uClibc with linker option -z RELRO"
2081 depends on HAVE_SHARED
2084 Build all libraries and executables with "ld -z relro".
2086 This tells the linker to mark chunks of an executable or shared
2087 library read-only after applying dynamic relocations. (This comes
2088 up when a global const variable is initialized to the address of a
2089 function or the value of another global variable.)
2091 This is a fairly obscure option the ld man page doesn't even bother
2092 to document properly. It's a security paranoia issue that's more
2093 likely to consume memory (by allocating an extra page) rather than
2096 This is explained in more depth at
2097 http://www.airs.com/blog/archives/189
2099 Nobody is likely to care whether you say Y or N here.
2101 config UCLIBC_BUILD_NOW
2102 bool "Build uClibc with linker option -z NOW"
2103 depends on HAVE_SHARED
2106 Build all libraries and executables with "ld -z now".
2108 This tells the linker to resolve all symbols when the library is
2109 first loaded, rather than when each function is first called. This
2110 increases start-up latency by a few microseconds and may do
2111 unnecessary work (resolving symbols that are never used), but the
2112 realtime people like it for making microbenchmark timings slightly
2113 more predictable and in some cases it can be slightly faster due to
2114 CPU cache behavior (not having to fault the linker back in to do
2115 lazy symbol resolution).
2117 Most people can't tell the difference between selecting Y or N here.
2119 config UCLIBC_BUILD_NOEXECSTACK
2120 bool "Build uClibc with noexecstack marking"
2123 Mark all assembler files as noexecstack, which will mark uClibc
2124 as not requiring an executable stack. (This doesn't prevent other
2125 files you link against from claiming to need an executable stack, it
2126 just won't cause uClibc to request it unnecessarily.)
2128 This is a security thing to make buffer overflows harder to exploit.
2129 By itself, it's kind of useless, as Linus Torvalds explained in 1998:
2130 http://old.lwn.net/1998/0806/a/linus-noexec.html
2132 It only actually provides any security when combined with address
2133 space randomization, explained here: http://lwn.net/Articles/121845/
2135 Address space randomization is on by default in current linux
2136 kernels (although it can be disabled using the option
2139 You should probably say Y.
2143 menu "uClibc development/debugging options"
2145 config CROSS_COMPILER_PREFIX
2146 string "Cross-compiling toolchain prefix"
2149 The prefix used to execute your cross-compiling toolchain. For
2150 example, if you run 'arm-linux-uclibc-gcc' to compile something,
2151 then enter 'arm-linux-uclibc-' here.
2153 config UCLIBC_EXTRA_CFLAGS
2154 string "Enter any extra CFLAGS to use to build uClibc"
2157 Add any additional CFLAGS to be used to build uClibc.
2160 bool "Build uClibc with debugging symbols"
2162 select EXTRA_WARNINGS
2164 Say Y here if you wish to compile uClibc with debugging symbols.
2165 This will allow you to use a debugger to examine uClibc internals
2166 while applications are running. This increases the size of the
2167 library considerably and should only be used when doing development.
2168 If you are doing development and want to debug uClibc, answer Y.
2170 Otherwise, answer N.
2173 bool "Build pthread with debugging output"
2174 depends on UCLIBC_HAS_THREADS && LINUXTHREADS_OLD
2177 Enable debug output in libpthread. This is only useful when doing
2178 development in libpthread itself.
2180 Otherwise, answer N.
2183 bool "Strip libraries and executables"
2187 Say Y here if you do wish to strip all uClibc libraries and
2188 executables. No stripping increases the size of the binaries
2189 considerably, but makes it possible to debug uClibc libraries.
2190 Most people will answer Y.
2193 bool "Build uClibc with run-time assertion testing"
2196 Say Y here to include runtime assertion tests.
2197 This enables runtime assertion testing in some code, which can
2198 increase the size of the library and incur runtime overhead.
2199 If you say N, then this testing will be disabled.
2201 config SUPPORT_LD_DEBUG
2202 bool "Build the shared library loader with debugging support"
2203 depends on HAVE_SHARED
2206 Answer Y here to enable all the extra code needed to debug the uClibc
2207 native shared library loader. The level of debugging noise that is
2208 generated depends on the LD_DEBUG environment variable... Just set
2209 LD_DEBUG to something like: 'LD_DEBUG=token1,token2,.. prog' to
2210 debug your application. Diagnostic messages will then be printed to
2213 For now these debugging tokens are available:
2214 detail provide more information for some options
2215 move display copy processing
2216 symbols display symbol table processing
2217 reloc display relocation processing; detail shows the
2219 nofixups never fixes up jump relocations
2220 bindings displays the resolve processing (function calls);
2221 detail shows the relocation patch
2222 all Enable everything!
2224 The additional environment variable:
2225 LD_DEBUG_OUTPUT=file
2226 redirects the diagnostics to an output file created using
2227 the specified name and the process id as a suffix.
2229 An excellent start is simply:
2230 $ LD_DEBUG=binding,move,symbols,reloc,detail ./appname
2231 or to log everything to a file named 'logfile', try this
2232 $ LD_DEBUG=all LD_DEBUG_OUTPUT=logfile ./appname
2234 If you are doing development and want to debug uClibc's shared library
2235 loader, answer Y. Mere mortals answer N.
2237 config SUPPORT_LD_DEBUG_EARLY
2238 bool "Build the shared library loader with early debugging support"
2239 depends on HAVE_SHARED
2242 Answer Y here to if you find the uClibc shared library loader is
2243 crashing or otherwise not working very early on. This is typical
2244 only when starting a new port when you haven't figured out how to
2245 properly get the values for argc, argv, environ, etc. This method
2246 allows a degree of visibility into the very early shared library
2247 loader initialization process. If you are doing development and want
2248 to debug the uClibc shared library loader early initialization,
2249 answer Y. Mere mortals answer N.
2251 config UCLIBC_MALLOC_DEBUGGING
2252 bool "Build malloc with debugging support"
2253 depends on MALLOC || MALLOC_STANDARD
2256 Answer Y here to compile extra debugging support code into malloc.
2257 Malloc debugging output may then be enabled at runtime using the
2258 MALLOC_DEBUG environment variable.
2260 The value of MALLOC_DEBUG should be an integer, which is interpreted
2261 as a bitmask with the following bits:
2262 1 - do extra consistency checking
2263 2 - output messages for malloc/free calls and OS
2265 4 - output messages for the `MMB' layer
2266 8 - output messages for internal malloc heap manipulation
2269 Because this increases the size of malloc appreciably (due to strings
2270 etc), you should say N unless you need to debug a malloc problem.
2273 string "Compiler Warnings"
2276 Set this to the set of gcc warnings you wish to see while compiling.
2278 config EXTRA_WARNINGS
2279 bool "Enable extra annoying warnings"
2282 If you wish to build with extra warnings enabled, say Y here.
2285 bool "Compile all sources at once into an object"
2288 Set this to compile all sources at once into an object (IMA).
2289 This mode of compilation uses alot of memory but may produce
2292 Note that you need a very recent GCC for this to work, like
2293 gcc >= 4.3 plus eventually some patches.
2295 If unsure, keep the default of N.
2297 config UCLIBC_MJN3_ONLY
2298 bool "Manuel's hidden warnings"
2301 Answer Y here to see all Manuel's personal notes, warnings, and todos.
2303 Most people will answer N.
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