2 # For a description of the syntax of this configuration file,
3 # see extra/config/Kconfig-language.txt
6 mainmenu "uClibc-ng $VERSION C Library Configuration"
8 config DESIRED_TARGET_ARCH
17 prompt "Target Architecture"
18 default TARGET_aarch64 if DESIRED_TARGET_ARCH = "aarch64"
19 default TARGET_alpha if DESIRED_TARGET_ARCH = "alpha"
20 default TARGET_arc if DESIRED_TARGET_ARCH = "arc"
21 default TARGET_arm if DESIRED_TARGET_ARCH = "arm"
22 default TARGET_avr32 if DESIRED_TARGET_ARCH = "avr32"
23 default TARGET_bfin if DESIRED_TARGET_ARCH = "bfin"
24 default TARGET_cris if DESIRED_TARGET_ARCH = "cris"
25 default TARGET_frv if DESIRED_TARGET_ARCH = "frv"
26 default TARGET_h8300 if DESIRED_TARGET_ARCH = "h8300"
27 default TARGET_hppa if DESIRED_TARGET_ARCH = "hppa"
28 default TARGET_i386 if DESIRED_TARGET_ARCH = "i386"
29 default TARGET_ia64 if DESIRED_TARGET_ARCH = "ia64"
30 default TARGET_lm32 if DESIRED_TARGET_ARCH = "lm32"
31 default TARGET_m68k if DESIRED_TARGET_ARCH = "m68k"
32 default TARGET_metag if DESIRED_TARGET_ARCH = "metag"
33 default TARGET_microblaze if DESIRED_TARGET_ARCH = "microblaze"
34 default TARGET_mips if DESIRED_TARGET_ARCH = "mips"
35 default TARGET_nds32 if DESIRED_TARGET_ARCH = "nds32"
36 default TARGET_nios2 if DESIRED_TARGET_ARCH = "nios2"
37 default TARGET_or1k if DESIRED_TARGET_ARCH = "or1k"
38 default TARGET_powerpc if DESIRED_TARGET_ARCH = "powerpc"
39 default TARGET_sh if DESIRED_TARGET_ARCH = "sh"
40 default TARGET_sparc if DESIRED_TARGET_ARCH = "sparc"
41 default TARGET_x86_64 if DESIRED_TARGET_ARCH = "x86_64"
42 default TARGET_xtensa if DESIRED_TARGET_ARCH = "xtensa"
44 The architecture of your target.
64 # someone could sync this tree:
65 # http://linux-c6x.org/git/?p=uClibc.git;a=summary
96 config TARGET_microblaze
111 config TARGET_powerpc
129 menu "Target Architecture Features and Options"
132 source "extra/Configs/Config.aarch64"
136 source "extra/Configs/Config.alpha"
140 source "extra/Configs/Config.arm"
144 source "extra/Configs/Config.avr32"
148 source "extra/Configs/Config.bfin"
152 source "extra/Configs/Config.cris"
156 source "extra/Configs/Config.frv"
160 source "extra/Configs/Config.h8300"
164 source "extra/Configs/Config.hppa"
168 source "extra/Configs/Config.i386"
172 source "extra/Configs/Config.ia64"
176 source "extra/Configs/Config.lm32"
180 source "extra/Configs/Config.m68k"
184 source "extra/Configs/Config.metag"
188 source "extra/Configs/Config.nds32"
192 source "extra/Configs/Config.nios2"
196 source "extra/Configs/Config.microblaze"
200 source "extra/Configs/Config.mips"
204 source "extra/Configs/Config.or1k"
208 source "extra/Configs/Config.powerpc"
212 source "extra/Configs/Config.sh"
216 source "extra/Configs/Config.sparc"
220 source "extra/Configs/Config.x86_64"
224 source "extra/Configs/Config.xtensa"
228 source "extra/Configs/Config.c6x"
232 source "extra/Configs/Config.arc"
235 config TARGET_SUBARCH
237 default "e500" if CONFIG_E500
238 default "classic" if CONFIG_CLASSIC
239 default "sh4" if CONFIG_SH4
240 default "sh4" if CONFIG_SH4A
241 default "" if CONFIG_386
242 default "i486" if CONFIG_486
243 default "i586" if CONFIG_586
244 default "i686" if CONFIG_686
245 default "arcv2" if CONFIG_ARC_CPU_HS
248 source "extra/Configs/Config.in.arch"
252 menu "General Library Settings"
258 bool "Generate only Position Independent Code (PIC)"
260 depends on !HAVE_NO_PIC
262 If you wish to build all of uClibc as PIC objects, then answer Y here.
263 If you are unsure, then you should answer N.
265 config ARCH_HAS_NO_SHARED
268 config ARCH_HAS_NO_LDSO
270 select ARCH_HAS_NO_SHARED
272 config ARCH_HAS_UCONTEXT
276 bool "Enable shared libraries"
277 depends on !ARCH_HAS_NO_SHARED
280 If you wish to build uClibc with support for shared libraries then
281 answer Y here. If you only want to build uClibc as a static library,
284 config FORCE_SHAREABLE_TEXT_SEGMENTS
285 bool "Only load shared libraries which can share their text segment"
286 depends on HAVE_SHARED
289 If you answer Y here, the uClibc native shared library loader will
290 only load shared libraries, which do not need to modify any
291 non-writable segments. These libraries haven't set the DT_TEXTREL
292 tag in the dynamic section (==> objdump).
293 All your libraries must be compiled with -fPIC or -fpic, and all
294 assembler function must be written as position independent code (PIC).
295 Enabling this option will make uClibc's shared library loader a
296 little bit smaller and guarantee that no memory will be wasted by
297 badly coded shared libraries.
299 config LDSO_LDD_SUPPORT
300 bool "Native 'ldd' support"
301 depends on HAVE_SHARED
304 Enable all the code needed to support traditional ldd,
305 which executes the shared library loader to resolve all dependencies
306 and then provide a list of shared libraries that are required for an
307 application to function. Disabling this option will make uClibc's
308 shared library loader a little bit smaller.
309 Most people will answer Y.
311 config LDSO_CACHE_SUPPORT
312 bool "Enable library loader cache (ld.so.conf)"
313 depends on HAVE_SHARED
316 Enable this to make use of /etc/ld.so.conf, the shared library loader
317 cache configuration file to support for non-standard library paths.
318 After updating this file, it is necessary to run 'ldconfig' to update
319 the /etc/ld.so.cache shared library loader cache file.
321 config LDSO_PRELOAD_ENV_SUPPORT
322 bool "Enable library loader LD_PRELOAD environment"
323 depends on HAVE_SHARED
326 Enable this to make use of LD_PRELOAD environment variable.
327 A whitespace-separated list of additional, user-specified, ELF shared
328 libraries to be loaded before all others. This can be used to
329 selectively override functions in other shared libraries. For
330 set-user-ID/set-group-ID ELF binaries, only libraries in the standard
331 search directories that are also set-user-ID will be loaded.
333 config LDSO_PRELOAD_FILE_SUPPORT
334 bool "Enable library loader preload file (ld.so.preload)"
335 depends on HAVE_SHARED
337 Enable this to make use of /etc/ld.so.preload. This file contains a
338 whitespace separated list of shared libraries to be loaded before
341 config LDSO_BASE_FILENAME
342 string "Shared library loader naming prefix"
343 depends on HAVE_SHARED && (LDSO_CACHE_SUPPORT || LDSO_PRELOAD_FILE_SUPPORT)
346 If you wish to support both uClibc and glibc on the same system, it
347 is necessary to set this to something other than "ld.so" to avoid
348 conflicts with glibc, which also uses "ld.so". This prevents both
349 libraries from using the same /etc/ld.so.* files. If you wish to
350 support both uClibc and glibc on the same system then you should set
351 this to "ld-uClibc.so".
353 Most people will leave this set to the default of "ld.so".
355 WARNING: Changing the default prefix could cause problems with
358 config LDSO_STANDALONE_SUPPORT
359 bool "Dynamic linker stand-alone mode support"
360 depends on HAVE_SHARED
362 The dynamic linker can be run either indirectly through running some
363 dynamically linked program or library (in which case no command line
364 options to the dynamic linker can be passed and, in the ELF case, the
365 dynamic linker which is stored in the .interp section of the program
366 is executed) or directly by running:
368 /lib/ld-uClibc.so.* [OPTIONS] [PROGRAM [ARGUMENTS]]
370 Stand-alone execution is a prerequisite for adding prelink
371 capabilities to uClibc dynamic linker, as well useful for testing an
372 updated version of the dynamic linker without breaking the system.
374 config LDSO_PRELINK_SUPPORT
375 bool "Dynamic linker prelink support"
376 depends on HAVE_SHARED
377 select LDSO_STANDALONE_SUPPORT
379 The dynamic linker can be used in stand-alone mode by the prelink tool
380 for prelinking ELF shared libraries and binaries to speed up startup
381 time. It also is able to load and handle prelinked libraries and
384 config UCLIBC_STATIC_LDCONFIG
385 bool "Link ldconfig statically"
386 depends on HAVE_SHARED
389 Enable this option to statically link the ldconfig binary.
391 Making ldconfig static can be beneficial if you have a library
392 problem and need to use ldconfig to recover. Sometimes it is
393 preferable to instead keep the size of the system down, in which
394 case you should disable this option.
397 bool "Enable ELF RUNPATH tag support"
398 depends on HAVE_SHARED
399 default y if LDSO_CACHE_SUPPORT
401 ELF's may have dynamic RPATH/RUNPATH tags. These tags list paths
402 which extend the library search paths. They are really only useful
403 if a package installs libraries in non standard locations and
404 ld.so.conf support is disabled.
406 Usage of RUNPATH tags is not too common, so disabling this feature
407 should be safe for most people.
409 config LDSO_RUNPATH_OF_EXECUTABLE
410 bool "Use executables RUNPATH/RPATH when searching for libraries."
411 depends on LDSO_RUNPATH
414 Use the executables RUNPATH/RPATH to find to find libraries even
415 though this behavour is not standard. Setting this option causes
416 the uclibc dynamic linker behavour to match the glibc dynamic linker.
418 config LDSO_SAFE_RUNPATH
419 bool "Allow only RUNPATH beginning with /"
420 depends on LDSO_RUNPATH
423 Allow only absolute path in RPATH/RUNPATH.
425 config LDSO_SEARCH_INTERP_PATH
426 bool "Add ldso path to lib search path"
427 depends on HAVE_SHARED
430 The ldso is told where it is being executed from and can use that
431 path to find related core libraries. This is useful by default,
432 but can be annoying in a mixed development environment.
434 i.e. if the ldso is run from /foo/boo/ldso.so, it will start its
435 library search with /foo/boo/
437 If unsure, simply say Y here.
439 config LDSO_LD_LIBRARY_PATH
440 bool "Add LD_LIBRARY_PATH to lib search path"
441 depends on HAVE_SHARED
444 On hardened system it could be useful to disable the use of
445 LD_LIBRARY_PATH environment variable (a colon-separated list of
446 directories in which to search for ELF libraries at execution-time).
448 If unsure, simply say Y here.
450 config LDSO_NO_CLEANUP
451 bool "Disable automatic unloading of dynamically loaded shared objects"
452 depends on HAVE_SHARED
454 If you need complete allocation traces when debugging memory leaks
455 using Valgrind in a process that dynamically loads shared objects,
456 then answer Y here. Unlike glibc, uClibc unloads all dynamically
457 loaded shared objects when a process exits, which prevents Valgrind
458 from correctly resolving the symbols from the unloaded shared objects.
459 Unless you know you need this, you should answer N.
461 config UCLIBC_CTOR_DTOR
465 If you wish to build uClibc with support for global constructor
466 (ctor) and global destructor (dtor) support, then answer Y here.
467 When ctor/dtor support is enabled, binaries linked with uClibc must
468 also be linked with crtbegin.o and crtend.o which are provided by gcc
469 (the "*startfile:" and "*endfile:" settings in your gcc specs file
470 may need to be adjusted to include these files). This support will
471 also add a small amount of additional size to each binary compiled vs
472 uClibc. If you will be using uClibc with C++, or if you need the gcc
473 __attribute__((constructor)) and __attribute__((destructor)) to work,
474 then you definitely want to answer Y here. If you don't need ctors
475 or dtors and want your binaries to be as small as possible, then
478 config LDSO_GNU_HASH_SUPPORT
479 bool "Enable GNU hash style support"
480 depends on HAVE_SHARED
482 Newest binutils support a new hash style named GNU-hash. The dynamic
483 linker will use the new GNU-hash section (.gnu.hash) for symbol lookup
484 if present into the ELF binaries, otherwise it will use the old SysV
485 hash style (.hash). This ensures that it is completely backward
487 Further, being the hash table implementation self-contained into each
488 executable and shared libraries, objects with mixed hash style can
489 peacefully coexist in the same process.
491 If you want to use this new feature, answer Y
494 prompt "Thread support"
495 default HAS_NO_THREADS
497 If you want to compile uClibc with pthread support, then answer Y.
498 This will increase the size of uClibc by adding a bunch of locking
499 to critical data structures, and adding extra code to ensure that
500 functions are properly reentrant.
502 config HAS_NO_THREADS
505 Disable thread support.
507 config UCLIBC_HAS_LINUXTHREADS
509 # linuxthreads need nanosleep()
510 select UCLIBC_HAS_REALTIME
511 depends on !TARGET_aarch64 && \
514 If you want to compile uClibc with Linuxthreads support, then answer Y.
516 config UCLIBC_HAS_THREADS_NATIVE
517 bool "Native POSIX Threading (NPTL)"
518 select UCLIBC_HAS_TLS
519 select UCLIBC_HAS_STDIO_FUTEXES
520 select UCLIBC_HAS_REALTIME
521 # i386 has no lowlevellock support (yet) as opposed to i486 onward
522 depends on !CONFIG_386 && \
536 If you want to compile uClibc with NPTL support, then answer Y.
540 config UCLIBC_HAS_THREADS
541 def_bool y if !HAS_NO_THREADS
543 config UCLIBC_HAS_TLS
544 bool "Thread-Local Storage"
545 depends on UCLIBC_HAS_THREADS_NATIVE
547 If you want to enable TLS support then answer Y.
548 This is fast an efficient way to store per-thread local data
549 which is not on stack. It needs __thread support enabled in
552 config PTHREADS_DEBUG_SUPPORT
553 bool "Build pthreads debugging support"
554 depends on UCLIBC_HAS_THREADS
556 Say Y here if you wish to be able to debug applications that use
557 uClibc's pthreads library. By enabling this option, a library
558 named libthread_db will be built. This library will be dlopen()'d
559 by gdb and will allow gdb to debug the threads in your application.
561 IMPORTANT NOTE! Because gdb must dlopen() the libthread_db library,
562 you must compile gdb with uClibc in order for pthread debugging to
565 If you are doing development and want to debug applications using
566 uClibc's pthread library, answer Y. Otherwise, answer N.
569 config UCLIBC_HAS_SYSLOG
570 bool "Syslog support"
572 depends on UCLIBC_HAS_NETWORK_SUPPORT
573 select UCLIBC_HAS_SOCKET
575 Support sending messages to the system logger.
576 This requires socket-support.
578 config UCLIBC_HAS_LFS
581 Large file support (always enabled; config symbol retained for
582 feature test to be compatible with uClibc).
584 prompt "Malloc Implementation"
585 default MALLOC if ! ARCH_USE_MMU
586 default MALLOC_STANDARD if ARCH_USE_MMU
591 "malloc" use mmap for all allocations and so works very well on
592 MMU-less systems that do not support the brk() system call. It is
593 pretty smart about reusing already allocated memory, and minimizing
595 This is the default for uClinux MMU-less systems.
600 "malloc-simple" is trivially simple and slow as molasses. It
601 was written from scratch for uClibc, and is the simplest possible
602 (and therefore smallest) malloc implementation.
604 This uses only the mmap() system call to allocate and free memory,
605 and does not use the brk() system call at all, making it a fine
606 choice for MMU-less systems with very limited memory. It's 100%
607 standards compliant, thread safe, very small, and releases freed
608 memory back to the OS immediately rather than keeping it in the
609 process's heap for reallocation. It is also VERY SLOW.
611 config MALLOC_STANDARD
612 bool "malloc-standard"
613 depends on ARCH_USE_MMU
615 "malloc-standard" is derived from the public domain dlmalloc
616 implementation by Doug Lea. It is quite fast, and is pretty smart
617 about reusing already allocated memory, and minimizing memory
618 wastage. This uses brk() for small allocations, while using mmap()
619 for larger allocations. This is the default malloc implementation
622 If unsure, answer "malloc-standard".
626 config UCLIBC_DYNAMIC_ATEXIT
627 bool "Dynamic atexit() Support"
630 When this option is enabled, uClibc will support an infinite number,
631 of atexit() and on_exit() functions, limited only by your available
632 memory. This can be important when uClibc is used with C++, since
633 global destructors are implemented via atexit(), and it is quite
634 possible to exceed the default number when this option is disabled.
635 Enabling this option adds a few bytes, and more significantly makes
636 atexit and on_exit depend on malloc, which can be bad when compiling
639 Unless you use uClibc with C++, you should probably answer N.
642 bool "Old (visible) atexit Support"
644 Enable this option if you want to update from 0.9.28 to git/0.9.29,
645 else you will be missing atexit() until you rebuild all apps.
647 config UCLIBC_HAS_UTMPX
648 bool "utmpx based support for tracking login/logouts to/from the system"
650 Answer y to enable support for accessing user accounting database.
651 It can be used to track all login/logout to the system.
653 config UCLIBC_HAS_UTMP
654 bool "utmp support (XPG2 compat, SVr4 compat)"
655 depends on UCLIBC_HAS_UTMPX
657 Answer y to enable legacy SVID support for accessing
658 user accounting database:
659 getutent(), getutid(), getutline(), pututline(),
660 setutent(), endutent(), utmpname() in utmp.h
661 It can be used to track all login/logout to the system.
663 If unsure, answer N and use corresponding POSIX functions
666 config UCLIBC_SUSV2_LEGACY
667 bool "Enable SuSv2 LEGACY functions"
669 Enable this option if you want to have SuSv2 LEGACY functions
670 Currently applies to:
674 WARNING! ABI incompatibility.
676 config UCLIBC_SUSV3_LEGACY
677 bool "Enable SuSv3 LEGACY functions"
683 Enable this option if you want to have SuSv3 LEGACY functions
684 in the library, else they are replaced by SuSv3 proposed macros.
685 Currently applies to:
687 bcmp, bcopy, bzero, index, rindex, ftime,
688 bsd_signal, (ecvt), (fcvt), gcvt, (getcontext),
689 (getwd), (makecontext),
690 mktemp, (pthread_attr_getstackaddr), (pthread_attr_setstackaddr),
691 scalb, (setcontext), (swapcontext), ualarm, usleep,
694 WARNING! ABI incompatibility.
696 config UCLIBC_HAS_CONTEXT_FUNCS
697 bool "Use obsolescent context control functions"
698 depends on UCLIBC_SUSV3_LEGACY && ARCH_HAS_UCONTEXT
700 Add into library the SuSv3 obsolescent functions used for context
701 control. The setcontext family allows the implementation in C of
702 advanced control flow patterns such as iterators, fibers, and
703 coroutines. They may be viewed as an advanced version of
704 setjmp/longjmp; whereas the latter allows only a single non-local jump
705 up the stack, setcontext allows the creation of multiple cooperative
706 threads of control, each with its own stack.
707 These functions are: setcontext, getcontext, makecontext, swapcontext.
709 config UCLIBC_SUSV3_LEGACY_MACROS
710 bool "Enable SuSv3 LEGACY macros"
712 Enable this option if you want to have SuSv3 LEGACY macros.
713 Currently applies to bcopy/bzero/bcmp/index/rindex et al.
714 WARNING! ABI incompatibility.
716 config UCLIBC_SUSV4_LEGACY
717 bool "Enable SuSv4 LEGACY or obsolescent functions"
719 Enable this option if you want to have SuSv4 LEGACY functions
720 and macros in the library.
721 Currently applies to:
724 _longjmp, _setjmp, _tolower, _toupper, ftw, getitimer,
725 gettimeofday, isascii, pthread_getconcurrency,
726 pthread_setconcurrency, setitimer, setpgrp, sighold,
727 sigignore, sigpause, sigrelse, sigset, siginterrupt,
728 tempnam, toascii, ulimit.
731 asctime, asctime_r, ctime, ctime_r, gets, rand_r,
734 WARNING! ABI incompatibility.
736 config UCLIBC_STRICT_HEADERS
737 bool "Hide structures and constants for unsupported features"
739 Hide structures and constants in headers that should not be used,
740 because the respective feature is disabled.
742 WARNING! enabling this option requires to patch many faulty apps,
743 since they make (wrongly) use of these structures/constants,
744 although the feature was disabled.
746 config UCLIBC_HAS_STUBS
747 bool "Provide stubs for unavailable functionality"
749 With this option uClibc provides non-functional stubs for
750 functions which are impossible to implement on the target
751 architecture. Otherwise, such functions are simply omitted.
753 config UCLIBC_HAS_SHADOW
754 bool "Shadow Password Support"
757 Answer N if you do not need shadow password support.
758 Most people will answer Y.
760 config UCLIBC_HAS_PROGRAM_INVOCATION_NAME
761 bool "Support for program_invocation_name"
763 Support for the GNU-specific program_invocation_name and
764 program_invocation_short_name strings. Some GNU packages
765 (like tar and coreutils) utilize these for extra useful
766 output, but in general are not required.
768 At startup, these external strings are automatically set
769 up based on the value of ARGV[0].
771 If unsure, just answer N.
773 config UCLIBC_HAS___PROGNAME
774 bool "Support for __progname"
777 Some packages (like openssh) like to peek into internal libc
778 symbols to make their output a bit more user friendly.
780 At startup, __progname is automatically set up based on the
783 If unsure, just answer N.
785 config UCLIBC_HAS_PTY
786 bool "Support for pseudo-terminals"
789 This enables support for pseudo-terminals (see man 4 pts
792 If unsure, just answer Y.
795 bool "Assume that /dev/pts is a devpts or devfs file system"
797 depends on UCLIBC_HAS_PTY
799 Enable this if /dev/pts is on a devpts or devfs filesystem. Both
800 these filesystems automatically manage permissions on the /dev/pts
801 devices. You may need to mount your devpts or devfs filesystem on
802 /dev/pts for this to work.
804 Most people should answer Y.
806 config UNIX98PTY_ONLY
807 bool "Support only Unix 98 PTYs"
809 depends on UCLIBC_HAS_PTY
811 If you want to support only Unix 98 PTYs enable this. Some older
812 applications may need this disabled and will thus use legacy BSD
813 style PTY handling which is more complex and also bigger than
814 Unix 98 PTY handling.
816 For most current programs, you can generally answer Y.
819 config UCLIBC_HAS_GETPT
820 bool "Support getpt() (glibc-compat)"
821 depends on UCLIBC_HAS_PTY
823 Some packages may need getpt().
824 All of those are non-standard and can be considered
825 GNU/libc compatibility.
826 Either use posix_openpt() or just open /dev/ptmx yourself.
828 If unsure, just say N.
832 # Have to use __libc_ptyname{1,2}[] and related bloat
833 config UCLIBC_HAS_GETPT
837 config UCLIBC_HAS_LIBUTIL
838 bool "Provide libutil library and functions"
839 depends on UCLIBC_HAS_PTY
841 Provide a libutil library.
842 This non-standard conforming library provides the following
845 forkpty(): combines openpty(), fork(2), and login_tty() to
846 create a new process operating in a pseudo-terminal.
847 login(): write utmp and wtmp entries
848 login_tty(): prepares for a login on the tty fd by creating a
849 new session, making fd the controlling terminal for
850 the calling process, setting fd to be the standard
851 input, output, and error streams of the current
852 process, and closing fd.
853 logout(): write utmp and wtmp entries
854 logwtmp(): constructs a utmp structure and calls updwtmp() to
855 append the structure to the utmp file.
856 openpty(): finds an available pseudo-terminal and returns
857 file descriptors for the master and slave
859 This library adds about 3k-4k to your system.
861 config UCLIBC_HAS_TM_EXTENSIONS
862 bool "Support 'struct tm' timezone extension fields"
865 Enabling this option adds fields to 'struct tm' in time.h for
866 tracking the number of seconds east of UTC, and an abbreviation for
867 the current timezone. These fields are not specified by the SuSv3
868 standard, but they are commonly used in both GNU and BSD application
871 To strictly follow the SuSv3 standard, leave this disabled.
872 Most people will probably want to answer Y.
874 config UCLIBC_HAS_TZ_CACHING
875 bool "Enable caching of the last valid timezone 'TZ' string"
878 Answer Y to enable caching of the last valid 'TZ' string describing
879 the timezone setting. This allows a quick string compare to avoid
880 repeated parsing of unchanged 'TZ' strings when tzset() is called.
882 Most people will answer Y.
884 config UCLIBC_HAS_TZ_FILE
885 bool "Enable '/etc/TZ' file support to set a default timezone (uClibc-specific)"
888 Answer Y to enable the setting of a default timezone for uClibc.
890 Ordinarily, uClibc gets the timezone information exclusively from the
891 'TZ' environment variable. In particular, there is no support for
892 the zoneinfo directory tree or the /etc/timezone file used by glibc.
894 With this option enabled, uClibc will use the value stored in the
895 file '/etc/TZ' (default path) to obtain timezone information if the
896 'TZ' environment variable is missing or has an invalid value. The
897 file consists of a single line (newline required) of text describing
898 the timezone in the format specified for the TZ environment variable.
900 Doing 'echo CST6CDT > /etc/TZ' is enough to create a valid file.
902 http://www.opengroup.org/onlinepubs/007904975/basedefs/xbd_chap08.html
903 for details on valid settings of 'TZ'.
905 Most people will answer Y.
907 config UCLIBC_HAS_TZ_FILE_READ_MANY
908 bool "Repeatedly read the '/etc/TZ' file"
909 depends on UCLIBC_HAS_TZ_FILE
912 Answer Y to enable repeated reading of the '/etc/TZ' file even after
913 a valid value has been read. This incurs the overhead of an
914 open/read/close for each tzset() call (explicit or implied). However,
915 setting this will allow applications to update their timezone
916 information if the contents of the file change.
918 Most people will answer Y.
920 config UCLIBC_TZ_FILE_PATH
921 string "Path to the 'TZ' file for setting the global timezone"
922 depends on UCLIBC_HAS_TZ_FILE
925 This is the path to the 'TZ' file.
927 Most people will use the default of '/etc/TZ'.
929 config UCLIBC_FALLBACK_TO_ETC_LOCALTIME
930 bool "Use /etc/localtime as a fallback"
931 depends on UCLIBC_HAS_TZ_FILE
934 Answer Y to try to use /etc/localtime file.
935 On glibc systems this file (if it is in TZif2 format)
936 contains timezone string at the end.
938 Most people will answer Y.
942 menu "Advanced Library Settings"
944 config UCLIBC_PWD_BUFFER_SIZE
945 int "Buffer size for getpwnam() and friends"
949 This sets the value of the buffer size for getpwnam() and friends.
950 By default, this is 256. (For reference, glibc uses 1024).
951 The value can be found using sysconf() with the _SC_GETPW_R_SIZE_MAX
954 config UCLIBC_GRP_BUFFER_SIZE
955 int "Buffer size for getgrnam() and friends"
959 This sets the value of the buffer size for getgrnam() and friends.
960 By default, this is 256. (For reference, glibc uses 1024).
961 The value can be found using sysconf() with the _SC_GETGR_R_SIZE_MAX
964 comment "Support various families of functions"
966 config UCLIBC_LINUX_SPECIFIC
967 bool "Linux specific functions"
970 accept4(), bdflush(),
971 capget(), capset(), eventfd(), fallocate(),
972 fstatfs(), getrandom(), inotify_*(), ioperm(), iopl(),
973 madvise(), modify_ldt(), pipe2(), personality(),
974 prctl()/arch_prctl(), pivot_root(), modify_ldt(),
975 ppoll(), readahead(), reboot(), remap_file_pages(),
976 sched_getaffinity(), sched_setaffinity(), sendfile(),
977 setfsgid(), setfsuid(), setresgid(), setresuid(),
978 splice(), vmsplice(), tee(), signalfd(), statfs(),
979 swapoff(), swapon(), sync_file_range(), syncfs(),
980 _sysctl(), sysinfo(), timerfd_*(), vhangup(), umount(),
983 config UCLIBC_HAS_GNU_ERROR
984 bool "Support GNU extensions for error-reporting"
987 Support for the GNU-specific error(), error_at_line(),
988 void (* error_print_progname)(), error_message_count
989 functions and variables. Some GNU packages
990 utilize these for extra useful output, but in general
993 If unsure, just answer N.
995 config UCLIBC_BSD_SPECIFIC
996 bool "BSD specific functions"
999 mincore(), getdomainname(), setdomainname()
1003 config UCLIBC_HAS_BSD_ERR
1004 bool "BSD err functions"
1007 These functions are non-standard BSD extensions.
1008 err(), errx(), warn(), warnx(), verr(), verrx(), vwarn(), vwarnx()
1012 config UCLIBC_HAS_OBSOLETE_BSD_SIGNAL
1013 bool "BSD obsolete signal functions"
1015 These functions are provided as a compatibility interface for
1016 programs that make use of the historical System V signal API.
1017 This API is obsolete:
1018 new applications should use the POSIX signal API (sigaction(2),
1019 sigprocmask(2), etc.).
1022 sigset(), sighold(), sigrelse(), sigignore()
1026 config UCLIBC_HAS_OBSOLETE_SYSV_SIGNAL
1027 bool "SYSV obsolete signal functions"
1029 Use of sysv_signal() should be avoided; use sigaction(2) instead.
1033 config UCLIBC_NTP_LEGACY
1034 bool "ntp_*() aliases"
1036 Provide legacy aliases for ntp functions:
1037 ntp_adjtime(), ntp_gettime()
1039 It is safe to say N here.
1041 config UCLIBC_SV4_DEPRECATED
1042 bool "Enable SVr4 deprecated functions"
1044 These functions are DEPRECATED in System V release 4.
1045 Say N unless you desparately need one of the functions below:
1047 ustat() [use statfs(2) in your code instead]
1049 config UCLIBC_HAS_REALTIME
1050 bool "Realtime-related family of SUSv functions"
1053 These functions are part of the Timers option and need not
1054 be available on all implementations.
1055 Includes AIO, message-queue, scheduler, semaphore functions:
1070 clock_getres(), clock_gettime(), clock_settime()
1072 mlockall(), munlockall()
1084 sched_get_priority_max(), sched_get_priority_min()
1085 sched_getscheduler()
1086 sched_rr_get_interval()
1088 sched_setscheduler()
1095 sem_trywait(), sem_wait()
1098 sigtimedwait(), sigwaitinfo()
1101 timer_getoverrun(), timer_gettime(), timer_settime()
1103 config UCLIBC_HAS_ADVANCED_REALTIME
1104 bool "Advanced realtime-related family of SUSv functions"
1106 depends on UCLIBC_HAS_REALTIME
1108 These functions are part of the Timers option and need not
1109 be available on all implementations.
1111 clock_getcpuclockid()
1120 posix_spawnattr_destroy(), posix_spawnattr_init()
1121 posix_spawnattr_getflags(), posix_spawnattr_setflags()
1122 posix_spawnattr_getpgroup(), posix_spawnattr_setpgroup()
1123 posix_spawnattr_getschedparam(), posix_spawnattr_setschedparam()
1124 posix_spawnattr_getschedpolicy(), posix_spawnattr_setschedpolicy()
1125 posix_spawnattr_getsigdefault(), posix_spawnattr_setsigdefault()
1126 posix_spawnattr_getsigmask(), posix_spawnattr_setsigmask()
1127 posix_spawn_file_actions_addclose()
1128 posix_spawn_file_actions_adddup2()
1129 posix_spawn_file_actions_addopen()
1130 posix_spawn_file_actions_destroy()
1131 posix_spawn_file_actions_init()
1134 posix_typed_mem_get_info()
1135 pthread_mutex_timedlock()
1138 #config UCLIBC_HAS_TERMIOS
1139 # bool "termios functions"
1142 # Get and set terminal attributes, line control, get and set baud
1144 # termios(), tcgetattr(), tcsetattr(), tcsendbreak(), tcdrain(),
1145 # tcflush(), tcflow(), cfmakeraw(), cfgetospeed(), cfgetispeed(),
1146 # cfsetispeed(), cfsetospeed(), cfsetspeed()
1150 config UCLIBC_HAS_EPOLL
1154 epoll_create(), epoll_ctl(), epoll_wait() functions.
1156 config UCLIBC_HAS_XATTR
1157 bool "Extended Attributes"
1160 Extended Attributes support.
1175 Say N unless you need support for extended attributes and the
1176 filesystems do actually support them.
1178 config UCLIBC_HAS_PROFILING
1179 bool "Profiling support"
1182 gcc's -finstrument-functions needs these.
1184 Most people can safely answer N.
1186 config UCLIBC_HAS_CRYPT_IMPL
1187 bool "libcrypt support"
1190 libcrypt contains crypt(), setkey() and encrypt()
1192 config UCLIBC_HAS_SHA256_CRYPT_IMPL
1193 bool "libcrypt SHA256 support"
1194 depends on UCLIBC_HAS_CRYPT_IMPL
1196 This adds support for SHA256 password hashing via the crypt() function.
1197 Say N here if you do not need SHA256 crypt support.
1199 config UCLIBC_HAS_SHA512_CRYPT_IMPL
1200 bool "libcrypt SHA512 support"
1201 depends on UCLIBC_HAS_CRYPT_IMPL
1203 This adds support for SHA512 password hashing via the crypt() function.
1204 Say N here if you do not need SHA512 crypt support.
1206 config UCLIBC_HAS_CRYPT_STUB
1207 bool "libcrypt stubs"
1209 depends on !UCLIBC_HAS_CRYPT_IMPL
1211 Standards mandate that crypt(3) provides a stub if it is unavailable.
1212 If you enable this option then stubs for
1213 crypt(), setkey() and encrypt()
1214 will be provided in a small libcrypt.
1216 config UCLIBC_HAS_CRYPT
1218 depends on UCLIBC_HAS_CRYPT_IMPL || UCLIBC_HAS_CRYPT_STUB
1221 menuconfig UCLIBC_HAS_NETWORK_SUPPORT
1222 bool "Networking Support"
1225 Say N here if you do not need network support.
1227 if UCLIBC_HAS_NETWORK_SUPPORT
1228 config UCLIBC_HAS_SOCKET
1229 bool "Socket support"
1232 If you want to include support for sockets then answer Y.
1234 config UCLIBC_HAS_IPV4
1235 bool "IP version 4 support"
1237 select UCLIBC_HAS_SOCKET
1239 If you want to include support for the Internet Protocol
1240 (IP version 4) then answer Y.
1242 Most people will say Y.
1244 config UCLIBC_HAS_IPV6
1245 bool "IP version 6 support"
1246 select UCLIBC_HAS_SOCKET
1248 If you want to include support for the next version of the Internet
1249 Protocol (IP version 6) then answer Y.
1251 Most people should answer N.
1253 config UCLIBC_HAS_RPC
1254 bool "Remote Procedure Call (RPC) support"
1255 # RPC+socket-ipvX doesn't currently work.
1256 depends on UCLIBC_HAS_IPV4 || UCLIBC_HAS_IPV6
1258 If you want to include RPC support, enable this. RPC is rarely used
1259 for anything except for the NFS filesystem. Unless you plan to use
1260 NFS, you can probably leave this set to N and save some space.
1262 If you need to use NFS then you should answer Y.
1264 config UCLIBC_HAS_FULL_RPC
1265 bool "Full RPC support"
1266 depends on UCLIBC_HAS_RPC
1267 default y if !HAVE_SHARED
1269 Normally we enable just enough RPC support for things like rshd and
1270 nfs mounts to work. If you find you need the rest of the RPC stuff,
1271 then enable this option. Most people can safely answer N.
1273 config UCLIBC_HAS_REENTRANT_RPC
1274 bool "Reentrant RPC support"
1275 depends on UCLIBC_HAS_RPC
1276 default y if !HAVE_SHARED
1278 Most packages utilize the normal (non-reentrant) RPC functions, but
1279 some (like exportfs from nfs-utils) need these reentrant versions.
1281 Most people can safely answer N.
1283 config UCLIBC_USE_NETLINK
1284 bool "Use netlink to query interfaces"
1285 depends on UCLIBC_HAS_SOCKET
1287 In newer versions of Linux (2.4.17+), support was added for querying
1288 network device information via netlink rather than the old style
1289 ioctl's. Most of the time, the older ioctl style is sufficient (and
1290 it is smaller than netlink), but if you find that not all of your
1291 devices are being returned by the if_nameindex() function, you will
1292 have to use the netlink implementation.
1294 Most people can safely answer N.
1296 config UCLIBC_SUPPORT_AI_ADDRCONFIG
1297 bool "Support the AI_ADDRCONFIG flag"
1298 depends on UCLIBC_USE_NETLINK
1300 The implementation of AI_ADDRCONFIG is aligned with the glibc
1301 implementation using netlink to query interfaces to find both
1302 ipv4 and ipv6 support. This is only needed if an application uses
1303 the AI_ADDRCONFIG flag.
1305 Most people can safely answer N.
1307 config UCLIBC_HAS_BSD_RES_CLOSE
1308 bool "Support res_close() (bsd-compat)"
1310 Answer Y if you desperately want to support BSD compatibility in
1313 Most people will say N.
1315 config UCLIBC_HAS_COMPAT_RES_STATE
1316 bool "Use compatible but bloated _res"
1319 Answer Y if you build network utilities and they muck with resolver
1320 internals a lot (_res global structure). uclibc does not use most
1321 of _res.XXX fields, and with this option OFF they won't even exist.
1322 Which will make e.g. dig build fail.
1323 Answering N saves around 400 bytes in bss.
1325 config UCLIBC_HAS_EXTRA_COMPAT_RES_STATE
1326 bool "Use extra compatible but extra bloated _res"
1328 Answer Y if selecting UCLIBC_HAS_COMPAT_RES_STATE is not enough.
1329 As far as I can say, this should never be needed.
1331 config UCLIBC_HAS_RESOLVER_SUPPORT
1332 bool "DNS resolver functions"
1333 select UCLIBC_HAS_COMPAT_RES_STATE
1334 depends on UCLIBC_HAS_IPV4 || UCLIBC_HAS_IPV6
1336 Provide implementations for DNS resolver functions.
1337 In particular, the following functions will be added to the
1340 ns_skiprr, ns_initparse, ns_parserr, ns_msg_getflag,
1341 res_mkquery, res_init, res_ninit, res_close, res_nclose
1342 res_query, res_search, res_querydomain,
1344 ns_name_uncompress, ns_name_ntop, ns_name_pton, ns_name_unpack,
1345 ns_name_pack, ns_name_compress, ns_name_skip, dn_skipname,
1346 ns_get16, ns_get32, ns_put16, ns_put32
1351 menu "String and Stdio Support"
1353 config UCLIBC_HAS_STRING_GENERIC_OPT
1354 bool "Use faster (but larger) generic string functions"
1357 Answer Y to use the (tweaked) glibc generic string functions.
1359 In general, they are faster (but 3-5K larger) than the base
1360 uClibc string functions which are optimized solely for size.
1362 Many people will answer Y.
1364 config UCLIBC_HAS_STRING_ARCH_OPT
1365 bool "Use arch-specific assembly string functions (where available)"
1368 Answer Y to use any archtecture-specific assembly language string
1369 functions available for this target plaform.
1371 Note that assembly implementations are not available for all string
1372 functions, so some generic (written in C) string functions may
1375 These are small and fast, the only reason _not_ to say Y here is
1376 for debugging purposes.
1378 config UCLIBC_HAS_STDIO_FUTEXES
1379 bool "Use futexes for multithreaded I/O locking"
1380 depends on UCLIBC_HAS_THREADS_NATIVE
1382 If you want to compile uClibc to use futexes for low-level
1383 I/O locking, answer Y. Otherwise, answer N.
1385 config UCLIBC_HAS_CTYPE_TABLES
1386 bool "Use Table Versions Of 'ctype.h' Functions."
1389 Answer Y to use table versions of the 'ctype.h' functions.
1390 While the non-table versions are often smaller when building
1391 statically linked apps, they work only in stub locale mode.
1393 Most people will answer Y.
1395 config UCLIBC_HAS_CTYPE_SIGNED
1396 bool "Support Signed Characters In 'ctype.h' Functions."
1397 depends on UCLIBC_HAS_CTYPE_TABLES
1400 Answer Y to enable support for passing signed char values to
1401 the 'ctype.h' functions. ANSI/ISO C99 and SUSv3 specify that
1402 these functions are only defined for unsigned char values and
1403 EOF. However, glibc allows negative signed char values as well
1404 in order to support 'broken old programs'.
1406 Most people will answer Y.
1409 prompt "ctype argument checking"
1410 depends on UCLIBC_HAS_CTYPE_TABLES
1411 default UCLIBC_HAS_CTYPE_UNSAFE
1413 Please select the invalid arg behavior you want for the 'ctype'
1416 The 'ctype' functions are now implemented using table lookups, with
1417 the arg being the index. This can result in incorrect memory accesses
1418 or even segfaults for args outside of the allowed range.
1420 NOTE: This only affects the 'ctype' _functions_. It does not affect
1421 the macro implementations.
1423 config UCLIBC_HAS_CTYPE_UNSAFE
1424 bool "Do not check -- unsafe"
1426 config UCLIBC_HAS_CTYPE_CHECKED
1427 bool "Detect and handle appropriately"
1429 config UCLIBC_HAS_CTYPE_ENFORCED
1430 bool "Issue a diagnostic and abort()"
1435 config UCLIBC_HAS_WCHAR
1436 bool "Wide Character Support"
1438 Answer Y to enable wide character support. This will make uClibc
1439 much larger. It is also currently required for locale support.
1441 Most people will answer N.
1443 config UCLIBC_HAS_LIBICONV
1444 bool "Iconv Support"
1445 select UCLIBC_HAS_WCHAR
1447 Add tiny iconv support for charset conversion from and to UTF-8.
1449 config UCLIBC_HAS_LIBINTL
1450 bool "Intl stubs support"
1452 If you enable this option you get stubs for the gettext family of
1455 config UCLIBC_HAS_LOCALE
1456 bool "Locale Support"
1457 select UCLIBC_HAS_WCHAR
1458 select UCLIBC_HAS_CTYPE_TABLES
1459 select UCLIBC_HAS_LIBICONV
1461 uClibc now has full ANSI/ISO C99 locale support (except for
1462 wcsftime() and collating items in regex). Be aware that enabling
1463 this option will make uClibc much larger.
1465 Enabling UCLIBC_HAS_LOCALE with the default set of supported locales
1466 (169 UTF-8 locales, and 144 locales for other codesets) will enlarge
1467 uClibc by around 300k. You can reduce this size by building your own
1468 custom set of locate data (see extra/locale/LOCALES for details).
1470 uClibc's locale support is still under development. For example,
1471 codesets using shift states are not currently supported. Support is
1472 planned in the next iteration of locale support.
1474 Answer Y to enable locale support. Most people will answer N.
1478 prompt "Locale data"
1479 depends on UCLIBC_HAS_LOCALE
1480 default UCLIBC_BUILD_MINIMAL_LOCALE
1482 config UCLIBC_BUILD_MINIMAL_LOCALE
1483 bool "Only selected locales"
1484 depends on UCLIBC_HAS_LOCALE
1486 If you do not need all locales that are available on your
1487 host-box, then set this to 'Y'.
1489 config UCLIBC_BUILD_ALL_LOCALE
1491 depends on UCLIBC_HAS_LOCALE
1493 This builds all the locales that are available on your
1498 config UCLIBC_BUILD_MINIMAL_LOCALES
1499 string "locales to use"
1500 depends on UCLIBC_BUILD_MINIMAL_LOCALE
1503 Space separated list of locales to use.
1510 config UCLIBC_HAS_XLOCALE
1511 bool "Extended Locale Support (experimental/incomplete)"
1512 depends on UCLIBC_HAS_LOCALE
1514 Answer Y to enable extended locale support similar to that provided
1515 by glibc. This is primarily intended to support libstd++
1517 However, it also allows thread-specific locale selection via
1520 Most people will answer N.
1522 config UCLIBC_HAS_HEXADECIMAL_FLOATS
1523 bool "Support hexadecimal float notation"
1524 depends on UCLIBC_HAS_CTYPE_TABLES
1525 depends on UCLIBC_HAS_FLOATS
1527 Answer Y to enable support for hexadecimal float notation in the
1528 (wchar and) char string to floating point conversion functions, as
1529 well as support for the %a and %A conversion specifiers in the
1530 *printf() and *scanf() functions.
1532 Most people will answer N.
1534 config UCLIBC_HAS_GLIBC_DIGIT_GROUPING
1535 bool "Support glibc's \"'\" flag for allowing locale-specific digit grouping"
1536 depends on UCLIBC_HAS_LOCALE
1537 depends on UCLIBC_HAS_FLOATS
1539 Answer Y to enable support for glibc's \"'\" flag for allowing
1540 locale-specific digit grouping in base 10 integer conversions and
1541 appropriate floating point conversions in the *printf() and *scanf()
1544 Most people will answer N.
1546 config UCLIBC_HAS_SCANF_LENIENT_DIGIT_GROUPING
1547 bool "Do not require digit grouping when the \"'\" flag is specified"
1548 depends on UCLIBC_HAS_GLIBC_DIGIT_GROUPING
1551 Answer Y to make digit grouping optional when the \"'\" flag is
1553 This is the standard glibc behavior. If the initial string of digits
1554 exceeds the maximum group number, the input will be treated as a
1555 normal non-grouped number.
1557 Most people will answer N.
1559 config UCLIBC_HAS_GLIBC_CUSTOM_PRINTF
1560 bool "Support glibc's register_printf_function() (glibc-compat)"
1561 depends on !USE_OLD_VFPRINTF
1563 Answer Y to support glibc's register_printf_function() to allow an
1564 application to add its own printf conversion specifiers.
1565 parse_printf_format() is also enabled.
1567 NOTE: Limits the number or registered specifiers to 10.
1568 NOTE: Requires new conversion specifiers to be ASCII
1569 characters (0-0x7f). This is to avoid problems with processing
1570 format strings in locales with different multibyte conversions.
1572 Most people will answer N.
1574 config USE_OLD_VFPRINTF
1575 bool "Use the old vfprintf implementation"
1576 depends on !UCLIBC_HAS_WCHAR
1578 Set to true to use the old vfprintf instead of the new. This is
1579 roughly C89 compliant with some extensions, and is much smaller.
1580 However, it does not support wide chars, positional args, or glibc
1581 custom printf specifiers.
1583 Most people will answer N.
1585 config UCLIBC_PRINTF_SCANF_POSITIONAL_ARGS
1586 int "Maximum number of positional args. Either 0 or >= 9."
1587 depends on !USE_OLD_VFPRINTF
1590 Set the maximum number of positional args supported by the
1591 printf/scanf functions. The Single Unix Specification Version 3
1592 requires a minimum value of 9. Setting this to a value lower than
1593 9 will disable positional arg support and cause the NL_ARGMAX macro
1594 in limits.h to be #undef'd.
1596 WARNING! The workspace to support positional args is currently
1597 allocated on the stack. You probably don't want to set
1598 this to too high a value.
1600 Most people will answer 9.
1603 prompt "Stdio buffer size"
1604 default UCLIBC_HAS_STDIO_BUFSIZ_4096
1606 Please select a value for BUFSIZ. This will be used by the
1607 stdio subsystem as the default buffer size for a file, and
1608 affects fopen(), setvbuf(), etc.
1610 NOTE: Setting this to 'none' will disable buffering completely.
1611 However, BUFSIZ will still be defined in stdio.h as 256 because
1612 many applications use this value.
1614 config UCLIBC_HAS_STDIO_BUFSIZ_NONE
1615 bool "none (WARNING - BUFSIZ will be 256 in stdio.h)"
1616 depends on !UCLIBC_HAS_WCHAR
1618 config UCLIBC_HAS_STDIO_BUFSIZ_256
1619 bool "256 (minimum ANSI/ISO C99 value)"
1621 config UCLIBC_HAS_STDIO_BUFSIZ_512
1624 config UCLIBC_HAS_STDIO_BUFSIZ_1024
1627 config UCLIBC_HAS_STDIO_BUFSIZ_2048
1630 config UCLIBC_HAS_STDIO_BUFSIZ_4096
1633 config UCLIBC_HAS_STDIO_BUFSIZ_8192
1636 # If you add more choices, you will need to update uClibc_stdio.h.
1641 prompt "Stdio builtin buffer size (uClibc-specific)"
1642 depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
1643 default UCLIBC_HAS_STDIO_BUILTIN_BUFFER_NONE
1645 When a FILE is created with fopen(), an attempt is made to allocate
1646 a BUFSIZ buffer for it. If the allocation fails, fopen() will still
1647 succeed but the FILE will be unbuffered.
1649 This option adds a small amount of space to each FILE to act as an
1650 emergency buffer in the event of a buffer allocation failure.
1652 Most people will answer None.
1654 config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_NONE
1657 config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_4
1660 config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_8
1663 # If you add more choices, you will need to update uClibc_stdio.h.
1667 config UCLIBC_HAS_STDIO_SHUTDOWN_ON_ABORT
1668 bool "Attempt to shutdown stdio subsystem when abort() is called."
1670 ANSI/ISO C99 requires abort() to be asyn-signal-safe. So there was
1671 a behavioral change made in SUSv3. Previously, abort() was required
1672 to have the affect of fclose() on all open streams. The wording has
1673 been changed to "may" from "shall".
1675 Most people will answer N.
1677 config UCLIBC_HAS_STDIO_GETC_MACRO
1678 bool "Provide a macro version of getc()"
1679 depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
1682 Provide a macro version of getc().
1684 Most people will answer Y.
1686 config UCLIBC_HAS_STDIO_PUTC_MACRO
1687 bool "Provide a macro version of putc()"
1688 depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
1691 Provide a macro version of putc().
1693 Most people will answer Y.
1695 config UCLIBC_HAS_STDIO_AUTO_RW_TRANSITION
1696 bool "Support auto-r/w transition"
1699 Answer Y to enable the stdio subsystem to automaticly transition
1700 between reading and writing. This relaxes the ANSI/ISO C99
1703 When a file is opened with update mode ('+' as the second or third
1704 character in the list of mode argument values), both input and output
1705 may be performed on the associated stream. However, output shall not
1706 be directly followed by input without an intervening call to the
1707 fflush function or to a file positioning function (fseek, fsetpos,
1708 or rewind), and input shall not be directly followed by output without
1709 an intervening call to a file positioning function, unless the input
1710 operation encounters endÂofÂfile.
1712 Most people will answer Y.
1714 config UCLIBC_HAS_FOPEN_LARGEFILE_MODE
1715 bool "Support an fopen() 'F' flag for large file mode (uClibc-specific)"
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_GNU_GETOPT
1810 bool "Support gnu getopt"
1813 Answer Y if you want to include full gnu getopt() instead of a
1814 (much smaller) SUSv3 compatible getopt().
1815 Note that getopt_long, getopt_long_only as well as getsubopt
1816 are implemented on top of this choice.
1818 Most people will answer Y.
1820 config UCLIBC_HAS_GETOPT_LONG
1821 bool "Support getopt_long/getopt_long_only (glibc-compat)"
1824 Answer Y if you want to include getopt_long[_only()] used by many
1827 Most people will answer Y.
1829 config UCLIBC_HAS_GNU_GETSUBOPT
1830 bool "Support getsubopt"
1833 Answer Y if you want to include getsubopt().
1835 Most people will answer Y.
1837 config UCLIBC_HAS_ARGP
1839 select UCLIBC_HAS_GETOPT_LONG
1840 select UCLIBC_HAS_GNU_GETOPT
1841 select UCLIBC_HAS_WCHAR
1844 Argp is an interface for parsing unix-style argument vectors. Unlike
1845 the common getopt interface, it provides many advanced features in
1846 addition to parsing options, such as automatic output in response to
1847 `--help' and `--version' options.
1848 A library can export an argp option parser, which programs can easily
1849 use in conjunction with their own option parser.
1850 Argp support is needed by elfutils libdw.
1852 Most people can safely answer N.
1859 config UCLIBC_HAS_REGEX
1860 bool "Regular Expression Support"
1863 POSIX regular expression code is really big -- 53k all by itself.
1864 If you don't use regular expressions, turn this off and save space.
1865 Of course, if you only statically link, leave this on, since it will
1866 only be included in your apps if you use regular expressions.
1868 config UCLIBC_HAS_REGEX_OLD
1869 bool "Use the older (stable) regular expression code"
1870 depends on UCLIBC_HAS_REGEX
1873 There are two versions of regex. The older (stable) version has
1874 been in uClibc for quite a long time but hasn't seen too many
1875 updates. It also has some known issues when dealing with uncommon
1876 corner cases and multibyte/unicode strings. However, it is quite
1877 a bit smaller than the newer version.
1879 If the older version has worked for you and you don't need unicode
1880 support, then stick with the old version (and say Y here).
1881 Otherwise, you should use the new version (and say N here).
1883 config UCLIBC_HAS_FNMATCH
1884 bool "fnmatch Support"
1889 config UCLIBC_HAS_FNMATCH_OLD
1890 bool "Use the older (stable) fnmatch code"
1891 depends on UCLIBC_HAS_FNMATCH
1894 There are two versions of fnmatch. The older (stable) version has
1895 been in uClibc for quite a long time but hasn't seen too many
1896 updates. It also has some known issues when dealing with uncommon
1897 corner cases and multibyte/unicode strings. However, it is quite
1898 a bit smaller than the newer version.
1900 If the older version has worked for you and you don't need unicode
1901 support, then stick with the old version (and say Y here).
1902 Otherwise, you should use the new version (and say N here).
1904 config UCLIBC_HAS_WORDEXP
1905 bool "Support the wordexp() interface"
1906 depends on UCLIBC_HAS_GLOB
1908 The SuSv3 wordexp() interface performs word expansions per the Shell
1909 and Utilities volume of IEEE Std 1003.1-2001, Section 2.6. It is
1910 intended for use by applications that want to implement all of the
1911 standard Bourne shell expansions on input data.
1913 This interface is rarely used, and very large. Unless you have a
1914 pressing need for wordexp(), you should probably answer N.
1916 config UCLIBC_HAS_NFTW
1917 bool "Support the nftw() interface"
1919 The SuSv3 nftw() interface is used to recursively descend
1920 directory paths while repeatedly calling a function.
1922 This interface is rarely used, and adds around 4.5k. Unless you have
1923 a pressing need for nftw(), you should probably answer N.
1925 config UCLIBC_HAS_FTW
1926 bool "Support the ftw() interface (SUSv4-obsolete)"
1927 depends on UCLIBC_SUSV4_LEGACY
1929 The SuSv3 ftw() interface is used to recursively descend
1930 directory paths while repeatedly calling a function.
1932 This interface is rarely used, and adds around 4.5k. Unless you have
1933 a pressing need for ftw(), you should probably answer N.
1935 config UCLIBC_HAS_FTS
1936 bool "Support the fts() interface (bsd-compat)"
1938 The fts functions are provided for traversing UNIX file hierarchies.
1940 This interface is currently used by the elfutils and adds
1942 You should port your application to use the POSIX nftw()
1945 Unless you need to build/use elfutils, you should prolly answer N.
1947 config UCLIBC_HAS_GLOB
1948 bool "Support the glob() interface"
1949 depends on UCLIBC_HAS_FNMATCH
1953 The glob interface is somewhat large (weighing in at about 2,5k). It
1954 is used fairly often, but is an option since people wanting to go for
1955 absolute minimum size may wish to omit it.
1957 Most people will answer Y.
1959 config UCLIBC_HAS_GNU_GLOB
1960 bool "Support gnu glob() interface"
1961 depends on UCLIBC_HAS_GLOB
1963 The gnu glob interface is somewhat larger (weighing in at about 4,2k)
1964 than it's SuSv3 counterpart (and is out of date). It is an old copy
1965 from glibc and does not support all the GNU specific options.
1967 Answer Y if you want to include full gnu glob() instead of the smaller
1968 SUSv3 compatible glob().
1970 Most people will answer N.
1977 menu "Library Installation Options"
1979 config RUNTIME_PREFIX
1980 string "uClibc runtime library directory"
1981 default "/usr/$(TARGET_ARCH)-linux-uclibc/"
1983 RUNTIME_PREFIX is the directory into which the uClibc runtime
1984 libraries will be installed. The result will look something
1987 lib/ <contains all runtime libraries>
1988 usr/bin/ldd <the ldd utility program>
1989 sbin/ldconfig <the ldconfig utility program>
1990 This value is used by the 'make install' Makefile target. Since this
1991 directory is compiled into the shared library loader, you will need to
1992 recompile uClibc if you change this value...
1994 For a typical target system this should be set to "/", such that
1995 'make install' will install /lib/libuClibc-<VERSION>.so
1998 string "uClibc development environment directory"
1999 default "/usr/$(TARGET_ARCH)-linux-uclibc/usr/"
2001 DEVEL_PREFIX is the directory into which the uClibc development
2002 environment will be installed. The result will look something
2005 lib/ <contains static libs>
2006 include/ <Where all the header files go>
2007 This value is used by the 'make install' Makefile target when
2008 installing a uClibc development environment.
2010 For a typical target system this should be set to "/usr", such that
2011 'make install' will install /usr/include/<header files>.
2014 string "library path component"
2017 Path component where libraries reside.
2019 For a typical target system this should be set to "lib", such that
2020 'make install' will install libraries to "/lib" and "/usr/lib"
2022 DEVEL_PREFIX/MULTILIB_DIR
2023 RUNTIME_PREFIX/MULTILIB_DIR
2025 Other settings may include "lib32" or "lib64".
2027 config HARDWIRED_ABSPATH
2028 bool "Hardwire absolute paths into linker scripts"
2031 This prepends absolute paths to the libraries mentioned in linker
2032 scripts such as libc.so.
2034 This is a build time optimization. It has no impact on dynamic
2035 linking at runtime, which doesn't use linker scripts.
2037 You must disable this to use uClibc with old non-sysroot toolchains,
2038 such as the prebuilt binary cross compilers at:
2039 http://uclibc.org/downloads/binaries
2041 The amount of time saved by this optimization is actually too small to
2042 measure. The linker just had to search the library path to find the
2043 linker script, so the dentries are cache hot if it has to search the
2044 same path again. But it's what glibc does, so we do it too.
2049 menu "Security options"
2051 config UCLIBC_BUILD_PIE
2052 bool "Build utilities as ET_DYN/PIE executables"
2053 depends on HAVE_SHARED
2054 depends on TARGET_arm || TARGET_frv || TARGET_i386 || TARGET_mips || TARGET_powerpc || TARGET_nds32
2055 select FORCE_SHAREABLE_TEXT_SEGMENTS
2057 If you answer Y here, ldd and iconv are built as ET_DYN/PIE
2060 It requires gcc-3.4 and binutils-2.15 (for arm 2.16) or later.
2061 More about ET_DYN/PIE binaries on <http://pax.grsecurity.net/> .
2063 WARNING: This option also enables FORCE_SHAREABLE_TEXT_SEGMENTS, so
2064 all libraries have to be built with -fPIC or -fpic, and all
2065 assembler functions must be written as position independent
2068 config UCLIBC_HAS_ARC4RANDOM
2069 bool "Include the arc4random() function"
2071 Answer Y to support the OpenBSD-like arc4random() function. This
2072 function picks a random number between 0 and N, and will always return
2073 something even if the random driver is dead. If urandom fails then
2074 gettimeofday(2) will be used as the random seed. This function is
2075 designed to be more dependable than invoking /dev/urandom directly.
2076 OpenSSL and OpenNTPD currently support this function.
2078 Most people will answer N.
2080 config ARC4RANDOM_USES_NODEV
2081 bool "Do not use /dev/urandom with arc4random()"
2082 depends on UCLIBC_HAS_ARC4RANDOM
2084 Answer Y to use gettimeofday(2) and getpid(2) exclusively for
2085 arc4random(). This is not a bad idea for a diskless system, but
2086 it uses a lot of syscalls to stir each array element.
2088 Most people will answer N.
2093 config UCLIBC_HAS_SSP
2094 bool "Support for GCC stack smashing protector"
2095 depends on !HAVE_NO_SSP
2097 Add code to support GCC's -fstack-protector[-all] option to uClibc.
2098 This requires GCC 4.1 or newer. GCC does not have to provide libssp,
2099 the needed functions are added to ldso/libc instead.
2101 GCC's stack protector is a reimplementation of IBM's propolice.
2102 See http://www.trl.ibm.com/projects/security/ssp/ and
2103 http://www.linuxfromscratch.org/hints/downloads/files/ssp.txt
2106 Note that NOEXECSTACK on a kernel with address space randomization
2107 is generally sufficient to prevent most buffer overflow exploits
2108 without increasing code size. This option essentially adds debugging
2111 Most people will answer N.
2113 config SSP_QUICK_CANARY
2114 bool "Use simple guard values without accessing /dev/urandom"
2115 depends on UCLIBC_HAS_SSP
2117 Use gettimeofday(2) to define the __guard without accessing
2119 WARNING: This makes smashing stack protector vulnerable to timing
2121 Most people will answer N.
2124 prompt "Propolice protection blocking signal"
2125 depends on UCLIBC_HAS_SSP
2127 default PROPOLICE_BLOCK_SEGV
2129 "abort" use SIGABRT to block offending programs.
2130 This is the default implementation.
2132 "segfault" use SIGSEGV to block offending programs.
2133 Use this for debugging.
2135 If unsure, answer "abort".
2137 config PROPOLICE_BLOCK_ABRT
2140 config PROPOLICE_BLOCK_SEGV
2145 config UCLIBC_BUILD_SSP
2146 bool "Build uClibc with -fstack-protector"
2147 depends on UCLIBC_HAS_SSP
2149 Build all uClibc libraries and executables with -fstack-protector,
2150 adding extra stack overflow checking to most uClibc functions.
2152 config UCLIBC_BUILD_RELRO
2153 bool "Build uClibc with linker option -z RELRO"
2154 depends on HAVE_SHARED
2157 Build all libraries and executables with "ld -z relro".
2159 This tells the linker to mark chunks of an executable or shared
2160 library read-only after applying dynamic relocations. (This comes
2161 up when a global const variable is initialized to the address of a
2162 function or the value of another global variable.)
2164 This is a fairly obscure option the ld man page doesn't even bother
2165 to document properly. It's a security paranoia issue that's more
2166 likely to consume memory (by allocating an extra page) rather than
2169 This is explained in more depth at
2170 http://www.airs.com/blog/archives/189
2172 Nobody is likely to care whether you say Y or N here.
2174 config UCLIBC_BUILD_NOW
2175 bool "Build uClibc with linker option -z NOW"
2176 depends on HAVE_SHARED
2178 Build all libraries and executables with "ld -z now".
2180 This tells the linker to resolve all symbols when the library is
2181 first loaded, rather than when each function is first called. This
2182 increases start-up latency by a few microseconds and may do
2183 unnecessary work (resolving symbols that are never used), but the
2184 realtime people like it for making microbenchmark timings slightly
2185 more predictable and in some cases it can be slightly faster due to
2186 CPU cache behavior (not having to fault the linker back in to do
2187 lazy symbol resolution).
2189 Most people can't tell the difference between selecting Y or N here.
2191 config UCLIBC_BUILD_NOEXECSTACK
2192 bool "Build uClibc with noexecstack marking"
2195 Mark all assembler files as noexecstack, which will mark uClibc
2196 as not requiring an executable stack. (This doesn't prevent other
2197 files you link against from claiming to need an executable stack, it
2198 just won't cause uClibc to request it unnecessarily.)
2200 This is a security thing to make buffer overflows harder to exploit.
2201 By itself, it's kind of useless, as Linus Torvalds explained in 1998:
2202 http://old.lwn.net/1998/0806/a/linus-noexec.html
2204 It only actually provides any security when combined with address
2205 space randomization, explained here: http://lwn.net/Articles/121845/
2207 Address space randomization is on by default in current linux
2208 kernels (although it can be disabled using the option
2211 You should probably say Y.
2215 menu "Development/debugging options"
2217 config CROSS_COMPILER_PREFIX
2218 string "Cross-compiling toolchain prefix"
2221 The prefix used to execute your cross-compiling toolchain. For
2222 example, if you run 'arm-linux-uclibc-gcc' to compile something,
2223 then enter 'arm-linux-uclibc-' here.
2225 config UCLIBC_EXTRA_CFLAGS
2226 string "Extra CFLAGS"
2229 Add any additional CFLAGS to be used to build uClibc.
2232 bool "Enable debugging symbols"
2233 select EXTRA_WARNINGS
2235 Say Y here if you wish to compile uClibc with debugging symbols.
2236 This will allow you to use a debugger to examine uClibc internals
2237 while applications are running. This increases the size of the
2238 library considerably and should only be used when doing development.
2239 If you are doing development and want to debug uClibc, answer Y.
2241 Otherwise, answer N.
2244 bool "Build pthread with debugging output"
2245 depends on UCLIBC_HAS_THREADS && UCLIBC_HAS_LINUXTHREADS
2247 Enable debug output in libpthread. This is only useful when doing
2248 development in libpthread itself.
2250 Otherwise, answer N.
2253 bool "Strip libraries and executables"
2257 Say Y here if you do wish to strip all uClibc libraries and
2258 executables. No stripping increases the size of the binaries
2259 considerably, but makes it possible to debug uClibc libraries.
2260 Most people will answer Y.
2263 bool "Build with run-time assertion testing"
2265 Say Y here to include runtime assertion tests.
2266 This enables runtime assertion testing in some code, which can
2267 increase the size of the library and incur runtime overhead.
2268 If you say N, then this testing will be disabled.
2270 config SUPPORT_LD_DEBUG
2271 bool "Build the shared library loader with debugging support"
2272 depends on HAVE_SHARED
2274 Answer Y here to enable all the extra code needed to debug the uClibc
2275 native shared library loader. The level of debugging noise that is
2276 generated depends on the LD_DEBUG environment variable... Just set
2277 LD_DEBUG to something like: 'LD_DEBUG=token1,token2,.. prog' to
2278 debug your application. Diagnostic messages will then be printed to
2281 For now these debugging tokens are available:
2282 detail provide more information for some options
2283 move display copy processing
2284 symbols display symbol table processing
2285 reloc display relocation processing; detail shows the
2287 nofixups never fixes up jump relocations
2288 bindings displays the resolve processing (function calls);
2289 detail shows the relocation patch
2290 all Enable everything!
2292 The additional environment variable:
2293 LD_DEBUG_OUTPUT=file
2294 redirects the diagnostics to an output file created using
2295 the specified name and the process id as a suffix.
2297 An excellent start is simply:
2298 $ LD_DEBUG=binding,move,symbols,reloc,detail ./appname
2299 or to log everything to a file named 'logfile', try this
2300 $ LD_DEBUG=all LD_DEBUG_OUTPUT=logfile ./appname
2302 If you are doing development and want to debug uClibc's shared library
2303 loader, answer Y. Mere mortals answer N.
2305 config SUPPORT_LD_DEBUG_EARLY
2306 bool "Build the shared library loader with early debugging support"
2307 depends on HAVE_SHARED
2309 Answer Y here to if you find the uClibc shared library loader is
2310 crashing or otherwise not working very early on. This is typical
2311 only when starting a new port when you haven't figured out how to
2312 properly get the values for argc, argv, environ, etc. This method
2313 allows a degree of visibility into the very early shared library
2314 loader initialization process. If you are doing development and want
2315 to debug the uClibc shared library loader early initialization,
2316 answer Y. Mere mortals answer N.
2318 config UCLIBC_MALLOC_DEBUGGING
2319 bool "Build malloc with debugging support"
2320 depends on MALLOC || MALLOC_STANDARD
2323 Answer Y here to compile extra debugging support code into malloc.
2324 Malloc debugging output may then be enabled at runtime using the
2325 MALLOC_DEBUG environment variable.
2327 The value of MALLOC_DEBUG should be an integer, which is interpreted
2328 as a bitmask with the following bits:
2329 1 - do extra consistency checking
2330 2 - output messages for malloc/free calls and OS
2332 4 - output messages for the `MMB' layer
2333 8 - output messages for internal malloc heap manipulation
2336 Because this increases the size of malloc appreciably (due to strings
2337 etc), you should say N unless you need to debug a malloc problem.
2339 config UCLIBC_HAS_BACKTRACE
2340 bool "Add support for application self-debugging"
2341 depends on HAVE_SHARED
2343 Answer Y here to compile support for application self-debugging that
2344 provides the following new functions:
2345 backtrace, backtrace_symbols, backtrace_symbols_fd
2347 The backtrace functionality is currently supported on some platforms, and it
2348 based on dwarf2 informations to properly work, so any application that
2349 want to use backtrace needs to be built with -fexceptions flag.
2351 The symbol names may be unavailable without the use of special linker
2352 options. For systems using the GNU linker, it is necessary to use the
2353 -rdynamic linker option too. Note that names of "static" functions are not
2354 exposed, and won't be available in the backtrace.
2357 string "Compiler Warnings"
2360 Set this to the set of compiler warnings you wish to see while compiling.
2362 config EXTRA_WARNINGS
2363 bool "Enable extra annoying warnings"
2365 If you wish to build with extra warnings enabled, say Y here.