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 support for 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
270 If you answer Y here, the uClibc native shared library loader will
271 only load shared libraries, which do not need to modify any
272 non-writable segments. These libraries haven't set the DT_TEXTREL
273 tag in the dynamic section (==> objdump).
274 All your libraries must be compiled with -fPIC or -fpic, and all
275 assembler function must be written as position independent code (PIC).
276 Enabling this option will make uClibc's shared library loader a
277 little bit smaller and guarantee that no memory will be wasted by
278 badly coded shared libraries.
280 config LDSO_LDD_SUPPORT
281 bool "Native 'ldd' support"
282 depends on HAVE_SHARED
285 Enable all the code needed to support traditional ldd,
286 which executes the shared library loader to resolve all dependencies
287 and then provide a list of shared libraries that are required for an
288 application to function. Disabling this option will makes uClibc's
289 shared library loader a little bit smaller.
290 Most people will answer Y.
292 config LDSO_CACHE_SUPPORT
293 bool "Enable library loader cache (ld.so.conf)"
294 depends on HAVE_SHARED
297 Enable this to make use of /etc/ld.so.conf, the shared library loader
298 cache configuration file to support for non-standard library paths.
299 After updating this file, it is necessary to run 'ldconfig' to update
300 the /etc/ld.so.cache shared library loader cache file.
302 config LDSO_PRELOAD_FILE_SUPPORT
303 bool "Enable library loader preload file (ld.so.preload)"
304 depends on HAVE_SHARED
307 Enable this to make use of /etc/ld.so.preload. This file contains a
308 whitespace separated list of shared libraries to be loaded before
311 config LDSO_BASE_FILENAME
312 string "Shared library loader naming prefix"
313 depends on HAVE_SHARED && (LDSO_CACHE_SUPPORT || LDSO_PRELOAD_FILE_SUPPORT)
316 If you wish to support both uClibc and glibc on the same system, it
317 is necessary to set this to something other than "ld.so" to avoid
318 conflicts with glibc, which also uses "ld.so". This prevents both
319 libraries from using the same /etc/ld.so.* files. If you wish to
320 support both uClibc and glibc on the same system then you should set
321 this to "ld-uClibc.so".
323 Most people will leave this set to the default of "ld.so".
325 WARNING: Changing the default prefix could cause problems with
328 config UCLIBC_STATIC_LDCONFIG
329 bool "Link ldconfig statically"
330 depends on HAVE_SHARED
333 Enable this option to statically link the ldconfig binary.
335 Making ldconfig static can be beneficial if you have a library
336 problem and need to use ldconfig to recover. Sometimes it is
337 preferable to instead keep the size of the system down, in which
338 case you should disable this option.
341 bool "Enable ELF RUNPATH tag support"
342 depends on HAVE_SHARED
343 default y if LDSO_CACHE_SUPPORT
344 default n if !LDSO_CACHE_SUPPORT
346 ELF's may have dynamic RPATH/RUNPATH tags. These tags list paths
347 which extend the library search paths. They are really only useful
348 if a package installs libraries in non standard locations and
349 ld.so.conf support is disabled.
351 Usage of RUNPATH tags is not too common, so disabling this feature
352 should be safe for most people.
354 config UCLIBC_CTOR_DTOR
355 bool "Support global constructors and destructors"
358 If you wish to build uClibc with support for global constructor
359 (ctor) and global destructor (dtor) support, then answer Y here.
360 When ctor/dtor support is enabled, binaries linked with uClibc must
361 also be linked with crtbegin.o and crtend.o which are provided by gcc
362 (the "*startfile:" and "*endfile:" settings in your gcc specs file
363 may need to be adjusted to include these files). This support will
364 also add a small amount of additional size to each binary compiled vs
365 uClibc. If you will be using uClibc with C++, or if you need the gcc
366 __attribute__((constructor)) and __attribute__((destructor)) to work,
367 then you definitely want to answer Y here. If you don't need ctors
368 or dtors and want your binaries to be as small as possible, then
371 config LDSO_GNU_HASH_SUPPORT
372 bool "Enable GNU hash style support"
373 depends on HAVE_SHARED
376 Newest binutils support a new hash style named GNU-hash. The dynamic
377 linker will use the new GNU-hash section (.gnu.hash) for symbol lookup
378 if present into the ELF binaries, otherwise it will use the old SysV
379 hash style (.hash). This ensures that it is completely backward
381 Further, being the hash table implementation self-contained into each
382 executable and shared libraries, objects with mixed hash style can
383 peacefully coexist in the same process.
385 If you want to use this new feature, answer Y
388 prompt "Thread support"
389 #default UCLIBC_HAS_THREADS_NATIVE if (TARGET_alpha || TARGET_arm || TARGET_i386 || TARGET_mips || TARGET_powerpc || TARGET_sh || TARGET_sh64)
390 default HAS_NO_THREADS
392 If you want to compile uClibc with pthread support, then answer Y.
393 This will increase the size of uClibc by adding a bunch of locking
394 to critical data structures, and adding extra code to ensure that
395 functions are properly reentrant.
397 config HAS_NO_THREADS
400 Disable thread support.
402 config LINUXTHREADS_OLD
403 bool "older (stable) version of linuxthreads"
404 # linuxthreads and linuxthreads.old need nanosleep()
405 select UCLIBC_HAS_REALTIME
407 There are two versions of linuxthreads. The older (stable) version
408 has been in uClibc for quite a long time but hasn't seen too many
409 updates other than bugfixes.
412 config LINUXTHREADS_NEW
413 bool "slightly newer version of linuxthreads"
415 The new version has not been tested much, and lacks ports for arches
416 which glibc does not support (like bfin/frv/etc...), but is based on
417 the latest code from glibc, so it may be the only choice for the
418 newer ports (like alpha/amd64/64bit arches and hppa).
420 config UCLIBC_HAS_THREADS_NATIVE
421 bool "Native POSIX Threading (NPTL)"
422 select UCLIBC_HAS_TLS
424 If you want to compile uClibc with NPTL support, then answer Y.
426 IMPORTANT NOTE! NPTL requires a Linux 2.6 kernel, binutils
427 at least version 2.16 and GCC with at least version 4.1.0. NPTL
428 will not work with older versions of any above sources. If you
429 ignore any of these guidelines, you do so at your own risk. Do
430 not ask for help on any of the development mailing lists.
432 !!!! WARNING !!!! BIG FAT WARNING !!!! REALLY BIG FAT WARNING !!!!
434 This is experimental code and at times it may not even build and
435 even if it does it might decide to do random damage. This code is
436 potentially hazardous to your health and sanity. It will remain
437 that way until further notice at which point this notice will
438 disappear. Thank you for your support and for not smoking.
442 config UCLIBC_HAS_THREADS
443 def_bool y if !HAS_NO_THREADS
445 config UCLIBC_HAS_TLS
446 bool "Thread-Local Storage"
447 depends on UCLIBC_HAS_THREADS_NATIVE
450 If you want to enable TLS support then answer Y.
451 This is fast an efficient way to store per-thread local data
452 which is not on stack. It needs __thread support enabled in
455 config PTHREADS_DEBUG_SUPPORT
456 bool "Build pthreads debugging support"
458 depends on UCLIBC_HAS_THREADS
460 Say Y here if you wish to be able to debug applications that use
461 uClibc's pthreads library. By enabling this option, a library
462 named libthread_db will be built. This library will be dlopen()'d
463 by gdb and will allow gdb to debug the threads in your application.
465 IMPORTANT NOTE! Because gdb must dlopen() the libthread_db library,
466 you must compile gdb with uClibc in order for pthread debugging to
469 If you are doing development and want to debug applications using
470 uClibc's pthread library, answer Y. Otherwise, answer N.
473 config UCLIBC_HAS_SYSLOG
474 bool "Syslog support"
476 depends on UCLIBC_HAS_NETWORK_SUPPORT
477 select UCLIBC_HAS_SOCKET
479 Support sending messages to the system logger.
480 This requires socket-support.
482 config UCLIBC_HAS_LFS
483 bool "Large File Support"
486 If you wish to build uClibc with support for accessing large files
487 (i.e. files greater then 2 GiB) then answer Y. Do not enable this
488 if you are using an older Linux kernel (2.0.x) that lacks large file
489 support. Enabling this option will increase the size of uClibc.
492 prompt "Malloc Implementation"
493 default MALLOC if ! ARCH_USE_MMU
494 default MALLOC_STANDARD if ARCH_USE_MMU
499 "malloc" use mmap for all allocations and so works very well on
500 MMU-less systems that do not support the brk() system call. It is
501 pretty smart about reusing already allocated memory, and minimizing
503 This is the default for uClinux MMU-less systems.
508 "malloc-simple" is trivially simple and slow as molasses. It
509 was written from scratch for uClibc, and is the simplest possible
510 (and therefore smallest) malloc implementation.
512 This uses only the mmap() system call to allocate and free memory,
513 and does not use the brk() system call at all, making it a fine
514 choice for MMU-less systems with very limited memory. It's 100%
515 standards compliant, thread safe, very small, and releases freed
516 memory back to the OS immediately rather than keeping it in the
517 process's heap for reallocation. It is also VERY SLOW.
519 config MALLOC_STANDARD
520 bool "malloc-standard"
521 depends on ARCH_USE_MMU
523 "malloc-standard" is derived from the public domain dlmalloc
524 implementation by Doug Lea. It is quite fast, and is pretty smart
525 about reusing already allocated memory, and minimizing memory
526 wastage. This uses brk() for small allocations, while using mmap()
527 for larger allocations. This is the default malloc implementation
530 If unsure, answer "malloc-standard".
534 config MALLOC_GLIBC_COMPAT
535 bool "Malloc returns live pointer for malloc(0)"
538 The behavior of malloc(0) is listed as implementation-defined by
539 SuSv3. Glibc returns a valid pointer to something, while uClibc
540 normally returns NULL. I personally feel glibc's behavior is
541 not particularly safe, and allows buggy applications to hide very
544 When this option is enabled, uClibc will act just like glibc, and
545 return a live pointer when someone calls malloc(0). This pointer
546 provides a malloc'ed area with a size of 1 byte. This feature is
547 mostly useful when dealing with applications using autoconf's broken
548 AC_FUNC_MALLOC macro (which redefines malloc as rpl_malloc if it
549 does not detect glibc style returning-a-valid-pointer-for-malloc(0)
550 behavior). Most people can safely answer N.
552 config UCLIBC_DYNAMIC_ATEXIT
553 bool "Dynamic atexit() Support"
556 When this option is enabled, uClibc will support an infinite number,
557 of atexit() and on_exit() functions, limited only by your available
558 memory. This can be important when uClibc is used with C++, since
559 global destructors are implemented via atexit(), and it is quite
560 possible to exceed the default number when this option is disabled.
561 Enabling this option adds a few bytes, and more significantly makes
562 atexit and on_exit depend on malloc, which can be bad when compiling
565 Unless you use uClibc with C++, you should probably answer N.
568 bool "Old (visible) atexit Support"
571 Enable this option if you want to update from 0.9.28 to git/0.9.29,
572 else you will be missing atexit() until you rebuild all apps.
574 config UCLIBC_SUSV3_LEGACY
575 bool "Enable SuSv3 LEGACY functions"
582 Enable this option if you want to have SuSv3 LEGACY functions
583 in the library, else they are replaced by SuSv3 proposed macros.
584 Currently applies to:
586 bcmp, bcopy, bzero, index, rindex, ftime,
587 bsd_signal, (ecvt), (fcvt), gcvt, (getcontext),
588 (getwd), (makecontext),
589 mktemp, (pthread_attr_getstackaddr), (pthread_attr_setstackaddr),
590 scalb, (setcontext), (swapcontext), ualarm, usleep,
593 WARNING! ABI incompatibility.
595 config UCLIBC_SUSV3_LEGACY_MACROS
596 bool "Enable SuSv3 LEGACY macros"
599 Enable this option if you want to have SuSv3 LEGACY macros.
600 Currently applies to bcopy/bzero/bcmp/index/rindex et al.
601 WARNING! ABI incompatibility.
603 config UCLIBC_SUSV4_LEGACY
604 bool "Enable SuSv4 LEGACY or obsolescent functions"
607 Enable this option if you want to have SuSv4 LEGACY functions
608 and macros in the library.
609 Currently applies to:
612 _longjmp, _setjmp, _tolower, _toupper, ftw, getitimer,
613 gettimeofday, isascii, pthread_getconcurrency,
614 pthread_setconcurrency, setitimer, setpgrp, sighold,
615 sigignore, sigpause, sigrelse, sigset, siginterrupt,
616 tempnam, toascii, ulimit.
619 asctime, asctime_r, ctime, ctime_r, gets, rand_r,
622 WARNING! ABI incompatibility.
624 config UCLIBC_HAS_STUBS
625 bool "Provide stubs for unavailable functionality"
628 With this option uClibc provides non-functional stubs for
629 functions which are impossible to implement on the target
630 architecture. Otherwise, such functions are simply omitted.
632 As of 2008-07, this option makes uClibc provide fork() stub
633 on NOMMU targets. It always sets errno to ENOSYS and returns -1.
635 This may be useful if you port a lot of software and cannot
636 audit all of it and replace or disable fork() usage.
637 With this option, a program which uses fork() will build
638 successfully. Of course, it may be useless if fork()
639 is essential for its operation.
641 config UCLIBC_HAS_SHADOW
642 bool "Shadow Password Support"
645 Answer N if you do not need shadow password support.
646 Most people will answer Y.
648 config UCLIBC_HAS_PROGRAM_INVOCATION_NAME
649 bool "Support for program_invocation_name"
652 Support for the GNU-specific program_invocation_name and
653 program_invocation_short_name strings. Some GNU packages
654 (like tar and coreutils) utilize these for extra useful
655 output, but in general are not required.
657 At startup, these external strings are automatically set
658 up based on the value of ARGV[0].
660 If unsure, just answer N.
662 config UCLIBC_HAS___PROGNAME
663 bool "Support for __progname"
665 depends on UCLIBC_HAS_PROGRAM_INVOCATION_NAME
667 Some packages (like openssh) like to peek into internal libc
668 symbols to make their output a bit more user friendly.
670 At startup, __progname is automatically set up based on the
673 If unsure, just answer N.
675 config UCLIBC_HAS_PTY
676 bool "Support for pseudo-terminals"
679 This enables support for pseudo-terminals (see man 4 pts
682 If unsure, just answer Y.
685 bool "Assume that /dev/pts is a devpts or devfs file system"
687 depends on UCLIBC_HAS_PTY
689 Enable this if /dev/pts is on a devpts or devfs filesystem. Both
690 these filesystems automatically manage permissions on the /dev/pts
691 devices. You may need to mount your devpts or devfs filesystem on
692 /dev/pts for this to work.
694 Most people should answer Y.
696 config UNIX98PTY_ONLY
697 bool "Support only Unix 98 PTYs"
699 depends on UCLIBC_HAS_PTY
701 If you want to support only Unix 98 PTYs enable this. Some older
702 applications may need this disabled and will thus use legacy BSD
703 style PTY handling which is more complex and also bigger than
704 Unix 98 PTY handling.
706 For most current programs, you can generally answer Y.
709 config UCLIBC_HAS_GETPT
710 bool "Support getpt() (glibc-compat)"
712 depends on UCLIBC_HAS_PTY
714 Some packages may need getpt().
715 All of those are non-standard and can be considered
716 GNU/libc compatibility.
717 Either use posix_openpt() or just open /dev/ptmx yourself.
719 If unsure, just say N.
723 # Have to use __libc_ptyname{1,2}[] and related bloat
724 config UCLIBC_HAS_GETPT
728 config UCLIBC_HAS_TM_EXTENSIONS
729 bool "Support 'struct tm' timezone extension fields"
732 Enabling this option adds fields to 'struct tm' in time.h for
733 tracking the number of seconds east of UTC, and an abbreviation for
734 the current timezone. These fields are not specified by the SuSv3
735 standard, but they are commonly used in both GNU and BSD application
738 To strictly follow the SuSv3 standard, leave this disabled.
739 Most people will probably want to answer Y.
741 config UCLIBC_HAS_TZ_CACHING
742 bool "Enable caching of the last valid timezone 'TZ' string"
745 Answer Y to enable caching of the last valid 'TZ' string describing
746 the timezone setting. This allows a quick string compare to avoid
747 repeated parsing of unchanged 'TZ' strings when tzset() is called.
749 Most people will answer Y.
751 config UCLIBC_HAS_TZ_FILE
752 bool "Enable '/etc/TZ' file support to set a default timezone (uClibc-specific)"
755 Answer Y to enable the setting of a default timezone for uClibc.
757 Ordinarily, uClibc gets the timezone information exclusively from the
758 'TZ' environment variable. In particular, there is no support for
759 the zoneinfo directory tree or the /etc/timezone file used by glibc.
761 With this option enabled, uClibc will use the value stored in the
762 file '/etc/TZ' (default path) to obtain timezone information if the
763 'TZ' environment variable is missing or has an invalid value. The
764 file consists of a single line (newline required) of text describing
765 the timezone in the format specified for the TZ environment variable.
767 Doing 'echo CST6CDT > /etc/TZ' is enough to create a valid file.
769 http://www.opengroup.org/onlinepubs/007904975/basedefs/xbd_chap08.html
770 for details on valid settings of 'TZ'.
772 Most people will answer Y.
774 config UCLIBC_HAS_TZ_FILE_READ_MANY
775 bool "Repeatedly read the '/etc/TZ' file"
776 depends on UCLIBC_HAS_TZ_FILE
779 Answer Y to enable repeated reading of the '/etc/TZ' file even after
780 a valid value has been read. This incurs the overhead of an
781 open/read/close for each tzset() call (explicit or implied). However,
782 setting this will allow applications to update their timezone
783 information if the contents of the file change.
785 Most people will answer Y.
787 config UCLIBC_TZ_FILE_PATH
788 string "Path to the 'TZ' file for setting the global timezone"
789 depends on UCLIBC_HAS_TZ_FILE
792 This is the path to the 'TZ' file.
794 Most people will use the default of '/etc/TZ'.
798 menu "Advanced Library Settings"
800 config UCLIBC_PWD_BUFFER_SIZE
801 int "Buffer size for getpwnam() and friends"
805 This sets the value of the buffer size for getpwnam() and friends.
806 By default, this is 256. (For reference, glibc uses 1024).
807 The value can be found using sysconf() with the _SC_GETPW_R_SIZE_MAX
810 config UCLIBC_GRP_BUFFER_SIZE
811 int "Buffer size for getgrnam() and friends"
815 This sets the value of the buffer size for getgrnam() and friends.
816 By default, this is 256. (For reference, glibc uses 1024).
817 The value can be found using sysconf() with the _SC_GETGR_R_SIZE_MAX
820 comment "Support various families of functions"
822 config UCLIBC_LINUX_MODULE_24
823 bool "Linux kernel module functions"
824 default !(TARGET_bfin)
826 create_module, query_module
827 are used in linux (prior to 2.6) for loadable kernel modules.
829 Say N if you do not use kernel modules, or you only support
832 config UCLIBC_LINUX_SPECIFIC
833 bool "Linux specific functions"
836 capget(), capset(), fstatfs(), inotify_*(), ioperm(), iopl(),
837 madvise(), modify_ldt(), personality(), prctl()/arch_prctl(),
838 ppoll(), readahead(), reboot(), remap_file_pages(),
839 sched_getaffinity(), sched_setaffinity(), sendfile(),
840 setfsgid(), setfsuid(), setresuid(),
841 splice(), vmsplice(), tee(), signalfd(), swapoff(), swapon(),
842 sync_file_range(), sysctl(), sysinfo(), vhangup()
844 config UCLIBC_HAS_GNU_ERROR
845 bool "Support GNU extensions for error-reporting"
848 Support for the GNU-specific error(), error_at_line(),
849 void (* error_print_progname)(), error_message_count
850 functions and variables. Some GNU packages
851 utilize these for extra useful output, but in general
854 If unsure, just answer N.
856 config UCLIBC_BSD_SPECIFIC
857 bool "BSD specific functions"
860 mincore(), getdomainname(), setdomainname()
864 config UCLIBC_HAS_BSD_ERR
865 bool "BSD err functions"
868 These functions are non-standard BSD extensions.
869 err(), errx(), warn(), warnx(), verr(), verrx(), vwarn(), vwarnx()
873 config UCLIBC_HAS_OBSOLETE_BSD_SIGNAL
874 bool "BSD obsolete signal functions"
877 These functions are provided as a compatibility interface for
878 programs that make use of the historical System V signal API.
879 This API is obsolete:
880 new applications should use the POSIX signal API (sigaction(2),
881 sigprocmask(2), etc.).
884 sigset(), sighold(), sigrelse(), sigignore()
888 config UCLIBC_HAS_OBSOLETE_SYSV_SIGNAL
889 bool "SYSV obsolete signal functions"
892 Use of sysv_signal() should be avoided; use sigaction(2) instead.
896 config UCLIBC_NTP_LEGACY
897 bool "ntp_*() aliases"
900 Provide legacy aliases for ntp functions:
901 ntp_adjtime(), ntp_gettime()
903 It is safe to say N here.
905 config UCLIBC_SV4_DEPRECATED
906 bool "Enable SVr4 deprecated functions"
909 These functions are DEPRECATED in System V release 4.
910 Say N unless you desparately need one of the functions below:
912 ustat() [use statfs(2) in your code instead]
914 config UCLIBC_HAS_REALTIME
915 bool "Realtime-related family of SUSv functions"
918 These functions are part of the Timers option and need not
919 be available on all implementations.
920 Includes AIO, message-queue, scheduler, semaphore functions:
935 clock_getres(), clock_gettime(), clock_settime()
937 mlockall(), munlockall()
949 sched_get_priority_max(), sched_get_priority_min()
951 sched_rr_get_interval()
960 sem_trywait(), sem_wait()
963 sigtimedwait(), sigwaitinfo()
966 timer_getoverrun(), timer_gettime(), timer_settime()
968 config UCLIBC_HAS_ADVANCED_REALTIME
969 bool "Advanced realtime-related family of SUSv functions"
971 depends on UCLIBC_HAS_REALTIME
973 These functions are part of the Timers option and need not
974 be available on all implementations.
976 clock_getcpuclockid()
985 posix_spawnattr_destroy(), posix_spawnattr_init()
986 posix_spawnattr_getflags(), posix_spawnattr_setflags()
987 posix_spawnattr_getpgroup(), posix_spawnattr_setpgroup()
988 posix_spawnattr_getschedparam(), posix_spawnattr_setschedparam()
989 posix_spawnattr_getschedpolicy(), posix_spawnattr_setschedpolicy()
990 posix_spawnattr_getsigdefault(), posix_spawnattr_setsigdefault()
991 posix_spawnattr_getsigmask(), posix_spawnattr_setsigmask()
992 posix_spawn_file_actions_addclose()
993 posix_spawn_file_actions_adddup2()
994 posix_spawn_file_actions_addopen()
995 posix_spawn_file_actions_destroy()
996 posix_spawn_file_actions_init()
999 posix_typed_mem_get_info()
1000 pthread_mutex_timedlock()
1003 #config UCLIBC_HAS_TERMIOS
1004 # bool "termios functions"
1007 # Get and set terminal attributes, line control, get and set baud
1009 # termios(), tcgetattr(), tcsetattr(), tcsendbreak(), tcdrain(),
1010 # tcflush(), tcflow(), cfmakeraw(), cfgetospeed(), cfgetispeed(),
1011 # cfsetispeed(), cfsetospeed(), cfsetspeed()
1015 config UCLIBC_HAS_EPOLL
1019 epoll_create(), epoll_ctl(), epoll_wait() functions.
1021 config UCLIBC_HAS_XATTR
1022 bool "Extended Attributes"
1025 Extended Attributes support.
1040 Say N unless you need support for extended attributes and the
1041 filesystems do actually support them.
1043 config UCLIBC_HAS_PROFILING
1044 bool "Profiling support"
1047 gcc's -finstrument-functions needs these.
1049 Most people can safely answer N.
1051 config UCLIBC_HAS_CRYPT_IMPL
1052 bool "libcrypt support"
1055 libcrypt contains crypt(), setkey() and encrypt()
1057 config UCLIBC_HAS_CRYPT_STUB
1058 bool "libcrypt stubs"
1060 depends on !UCLIBC_HAS_CRYPT_IMPL
1062 Standards mandate that crypt(3) provides a stub if it is unavailable.
1063 If you enable this option then stubs for
1064 crypt(), setkey() and encrypt()
1065 will be provided in a small libcrypt.
1067 config UCLIBC_HAS_CRYPT
1069 depends on UCLIBC_HAS_CRYPT_IMPL || UCLIBC_HAS_CRYPT_STUB
1072 menuconfig UCLIBC_HAS_NETWORK_SUPPORT
1073 bool "Networking Support"
1076 Say N here if you do not need network support.
1078 if UCLIBC_HAS_NETWORK_SUPPORT
1079 config UCLIBC_HAS_SOCKET
1080 bool "Socket support"
1083 If you want to include support for sockets then answer Y.
1085 config UCLIBC_HAS_IPV4
1086 bool "IP version 4 support"
1088 select UCLIBC_HAS_SOCKET
1090 If you want to include support for the Internet Protocol
1091 (IP version 4) then answer Y.
1093 Most people will say Y.
1095 config UCLIBC_HAS_IPV6
1096 bool "IP version 6 support"
1098 select UCLIBC_HAS_SOCKET
1100 If you want to include support for the next version of the Internet
1101 Protocol (IP version 6) then answer Y.
1103 Most people should answer N.
1105 config UCLIBC_HAS_RPC
1106 bool "Remote Procedure Call (RPC) support"
1108 # RPC+socket-ipvX doesn't currently work.
1109 depends on UCLIBC_HAS_IPV4 || UCLIBC_HAS_IPV6
1111 If you want to include RPC support, enable this. RPC is rarely used
1112 for anything except for the NFS filesystem. Unless you plan to use
1113 NFS, you can probably leave this set to N and save some space.
1115 If you need to use NFS then you should answer Y.
1117 config UCLIBC_HAS_FULL_RPC
1118 bool "Full RPC support"
1119 depends on UCLIBC_HAS_RPC
1120 default y if !HAVE_SHARED
1122 Normally we enable just enough RPC support for things like rshd and
1123 nfs mounts to work. If you find you need the rest of the RPC stuff,
1124 then enable this option. Most people can safely answer N.
1126 config UCLIBC_HAS_REENTRANT_RPC
1127 bool "Reentrant RPC support"
1128 depends on UCLIBC_HAS_RPC
1129 default y if !HAVE_SHARED
1131 Most packages utilize the normal (non-reentrant) RPC functions, but
1132 some (like exportfs from nfs-utils) need these reentrant versions.
1134 Most people can safely answer N.
1136 config UCLIBC_USE_NETLINK
1137 bool "Use netlink to query interfaces"
1139 depends on UCLIBC_HAS_SOCKET
1141 In newer versions of Linux (2.4.17+), support was added for querying
1142 network device information via netlink rather than the old style
1143 ioctl's. Most of the time, the older ioctl style is sufficient (and
1144 it is smaller than netlink), but if you find that not all of your
1145 devices are being returned by the if_nameindex() function, you will
1146 have to use the netlink implementation.
1148 Most people can safely answer N.
1150 config UCLIBC_SUPPORT_AI_ADDRCONFIG
1151 bool "Support the AI_ADDRCONFIG flag"
1152 depends on UCLIBC_USE_NETLINK
1155 The implementation of AI_ADDRCONFIG is aligned with the glibc
1156 implementation using netlink to query interfaces to find both
1157 ipv4 and ipv6 support. This is only needed if an application uses
1158 the AI_ADDRCONFIG flag.
1160 Most people can safely answer N.
1162 config UCLIBC_HAS_BSD_RES_CLOSE
1163 bool "Support res_close() (bsd-compat)"
1166 Answer Y if you desperately want to support BSD compatibility in
1169 Most people will say N.
1171 config UCLIBC_HAS_COMPAT_RES_STATE
1172 bool "Use compatible but bloated _res"
1175 Answer Y if you build network utilities and they muck with resolver
1176 internals a lot (_res global structure). uclibc does not use most
1177 of _res.XXX fields, and with this option OFF they won't even exist.
1178 Which will make e.g. dig build fail.
1179 Answering N saves around 400 bytes in bss.
1181 config UCLIBC_HAS_EXTRA_COMPAT_RES_STATE
1182 bool "Use extra compatible but extra bloated _res"
1185 Answer Y if selecting UCLIBC_HAS_COMPAT_RES_STATE is not enough.
1186 As far as I can say, this should never be needed.
1188 config UCLIBC_HAS_RESOLV_STUB
1189 bool "Provide libresolv stub"
1192 Provide a dummy resolv library.
1197 menu "String and Stdio Support"
1199 config UCLIBC_HAS_STRING_GENERIC_OPT
1200 bool "Use faster (but larger) generic string functions"
1203 Answer Y to use the (tweaked) glibc generic string functions.
1205 In general, they are faster (but 3-5K larger) than the base
1206 uClibc string functions which are optimized solely for size.
1208 Many people will answer Y.
1210 config UCLIBC_HAS_STRING_ARCH_OPT
1211 bool "Use arch-specific assembly string functions (where available)"
1214 Answer Y to use any archtecture-specific assembly language string
1215 functions available for this target plaform.
1217 Note that assembly implementations are not available for all string
1218 functions, so some generic (written in C) string functions may
1221 These are small and fast, the only reason _not_ to say Y here is
1222 for debugging purposes.
1224 config UCLIBC_HAS_CTYPE_TABLES
1225 bool "Use Table Versions Of 'ctype.h' Functions."
1228 Answer Y to use table versions of the 'ctype.h' functions.
1229 While the non-table versions are often smaller when building
1230 statically linked apps, they work only in stub locale mode.
1232 Most people will answer Y.
1234 config UCLIBC_HAS_CTYPE_SIGNED
1235 bool "Support Signed Characters In 'ctype.h' Functions."
1236 depends on UCLIBC_HAS_CTYPE_TABLES
1239 Answer Y to enable support for passing signed char values to
1240 the 'ctype.h' functions. ANSI/ISO C99 and SUSv3 specify that
1241 these functions are only defined for unsigned char values and
1242 EOF. However, glibc allows negative signed char values as well
1243 in order to support 'broken old programs'.
1245 Most people will answer Y.
1248 prompt "ctype argument checking"
1249 depends on UCLIBC_HAS_CTYPE_TABLES
1250 default UCLIBC_HAS_CTYPE_UNSAFE
1252 Please select the invalid arg behavior you want for the 'ctype'
1255 The 'ctype' functions are now implemented using table lookups, with
1256 the arg being the index. This can result in incorrect memory accesses
1257 or even segfaults for args outside of the allowed range.
1259 NOTE: This only affects the 'ctype' _functions_. It does not affect
1260 the macro implementations.
1262 config UCLIBC_HAS_CTYPE_UNSAFE
1263 bool "Do not check -- unsafe"
1265 config UCLIBC_HAS_CTYPE_CHECKED
1266 bool "Detect and handle appropriately"
1268 config UCLIBC_HAS_CTYPE_ENFORCED
1269 bool "Issue a diagnostic and abort()"
1274 config UCLIBC_HAS_WCHAR
1275 bool "Wide Character Support"
1278 Answer Y to enable wide character support. This will make uClibc
1279 much larger. It is also currently required for locale support.
1281 Most people will answer N.
1283 config UCLIBC_HAS_LOCALE
1284 bool "Locale Support"
1285 select UCLIBC_HAS_WCHAR
1286 select UCLIBC_HAS_CTYPE_TABLES
1289 uClibc now has full ANSI/ISO C99 locale support (except for
1290 wcsftime() and collating items in regex). Be aware that enabling
1291 this option will make uClibc much larger.
1293 Enabling UCLIBC_HAS_LOCALE with the default set of supported locales
1294 (169 UTF-8 locales, and 144 locales for other codesets) will enlarge
1295 uClibc by around 300k. You can reduce this size by building your own
1296 custom set of locate data (see extra/locale/LOCALES for details).
1298 uClibc's locale support is still under development. For example,
1299 codesets using shift states are not currently supported. Support is
1300 planned in the next iteration of locale support.
1302 Answer Y to enable locale support. Most people will answer N.
1306 prompt "Locale data"
1307 depends on UCLIBC_HAS_LOCALE
1308 default UCLIBC_BUILD_ALL_LOCALE
1310 config UCLIBC_BUILD_ALL_LOCALE
1312 depends on UCLIBC_HAS_LOCALE
1314 This builds all the locales that are available on your
1317 config UCLIBC_BUILD_MINIMAL_LOCALE
1318 bool "Only selected locales"
1319 depends on UCLIBC_HAS_LOCALE
1321 If you do not need all locales that are available on your
1322 host-box, then set this to 'Y'.
1324 config UCLIBC_PREGENERATED_LOCALE_DATA
1325 bool "Use Pre-generated Locale Data"
1326 depends on UCLIBC_HAS_LOCALE
1328 Use pre-built locale data.
1330 Note that these pregenerated locales are sensitive to your
1331 target architecture (endianess, bitcount).
1333 Saying N here is highly recommended.
1337 config UCLIBC_BUILD_MINIMAL_LOCALES
1338 string "locales to use"
1339 depends on UCLIBC_BUILD_MINIMAL_LOCALE
1342 Space separated list of locales to use.
1349 config UCLIBC_DOWNLOAD_PREGENERATED_LOCALE_DATA
1350 bool "Automagically Download the Pre-generated Locale Data (if necessary)"
1351 depends on UCLIBC_PREGENERATED_LOCALE_DATA
1354 If you would like the build process to use 'wget' to automatically
1355 download the pregenerated locale data, enable this option. Otherwise
1356 you will need to obtain the locale data yourself from:
1357 http://www.uclibc.org/downloads/uClibc-locale-*.tgz
1358 and place the uClibc-locale-*.tgz tarball in the extra/locale/
1361 Note that the use of pregenerated locale data is discouraged.
1363 config UCLIBC_HAS_XLOCALE
1364 bool "Extended Locale Support (experimental/incomplete)"
1365 depends on UCLIBC_HAS_LOCALE
1368 Answer Y to enable extended locale support similar to that provided
1369 by glibc. This is primarily intended to support libstd++
1371 However, it also allows thread-specific locale selection via
1374 Most people will answer N.
1376 config UCLIBC_HAS_HEXADECIMAL_FLOATS
1377 bool "Support hexadecimal float notation"
1378 depends on UCLIBC_HAS_CTYPE_TABLES
1379 depends on UCLIBC_HAS_FLOATS
1382 Answer Y to enable support for hexadecimal float notation in the
1383 (wchar and) char string to floating point conversion functions, as
1384 well as support for the %a and %A conversion specifiers in the
1385 *printf() and *scanf() functions.
1387 Most people will answer N.
1389 config UCLIBC_HAS_GLIBC_DIGIT_GROUPING
1390 bool "Support glibc's \"'\" flag for allowing locale-specific digit grouping"
1391 depends on UCLIBC_HAS_LOCALE
1392 depends on UCLIBC_HAS_FLOATS
1395 Answer Y to enable support for glibc's \"'\" flag for allowing
1396 locale-specific digit grouping in base 10 integer conversions and
1397 appropriate floating point conversions in the *printf() and *scanf()
1400 Most people will answer N.
1402 config UCLIBC_HAS_SCANF_LENIENT_DIGIT_GROUPING
1403 bool "Do not require digit grouping when the \"'\" flag is specified"
1404 depends on UCLIBC_HAS_GLIBC_DIGIT_GROUPING
1407 Answer Y to make digit grouping optional when the \"'\" flag is
1409 This is the standard glibc behavior. If the initial string of digits
1410 exceeds the maximum group number, the input will be treated as a
1411 normal non-grouped number.
1413 Most people will answer N.
1415 config UCLIBC_HAS_GLIBC_CUSTOM_PRINTF
1416 bool "Support glibc's register_printf_function() (glibc-compat)"
1417 depends on !USE_OLD_VFPRINTF
1420 Answer Y to support glibc's register_printf_function() to allow an
1421 application to add its own printf conversion specifiers.
1423 NOTE: Limits the number or registered specifiers to 10.
1424 NOTE: Requires new conversion specifiers to be ASCII
1425 characters (0-0x7f). This is to avoid problems with processing
1426 format strings in locales with different multibyte conversions.
1428 Most people will answer N.
1430 config USE_OLD_VFPRINTF
1431 bool "Use the old vfprintf implementation"
1432 depends on !UCLIBC_HAS_WCHAR
1435 Set to true to use the old vfprintf instead of the new. This is
1436 roughly C89 compliant with some extensions, and is much smaller.
1437 However, it does not support wide chars, positional args, or glibc
1438 custom printf specifiers.
1440 Most people will answer N.
1442 config UCLIBC_PRINTF_SCANF_POSITIONAL_ARGS
1443 int "Maximum number of positional args. Either 0 or >= 9."
1444 depends on !USE_OLD_VFPRINTF
1447 Set the maximum number of positional args supported by the
1448 printf/scanf functions. The Single Unix Specification Version 3
1449 requires a minimum value of 9. Setting this to a value lower than
1450 9 will disable positional arg support and cause the NL_ARGMAX macro
1451 in limits.h to be #undef'd.
1453 WARNING! The workspace to support positional args is currently
1454 allocated on the stack. You probably don't want to set
1455 this to too high a value.
1457 Most people will answer 9.
1460 config UCLIBC_HAS_SCANF_GLIBC_A_FLAG
1461 bool "Support glibc's 'a' flag for scanf string conversions (not implemented)"
1464 NOTE!!! Currently Not Implemented!!! Just A Place Holder!! NOTE!!!
1465 NOTE!!! Conflicts with an ANSI/ISO C99 scanf flag!! NOTE!!!
1467 Answer Y to enable support for glibc's 'a' flag for the scanf string
1468 conversions '%s', '%[', '%ls', '%l[', and '%S'. This is used to
1469 auto-allocate sufficient memory to hold the data retrieved.
1471 Most people will answer N.
1474 prompt "Stdio buffer size"
1475 default UCLIBC_HAS_STDIO_BUFSIZ_4096
1477 Please select a value for BUFSIZ. This will be used by the
1478 stdio subsystem as the default buffer size for a file, and
1479 affects fopen(), setvbuf(), etc.
1481 NOTE: Setting this to 'none' will disable buffering completely.
1482 However, BUFSIZ will still be defined in stdio.h as 256 because
1483 many applications use this value.
1485 config UCLIBC_HAS_STDIO_BUFSIZ_NONE
1486 bool "none (WARNING - BUFSIZ will be 256 in stdio.h)"
1487 depends on !UCLIBC_HAS_WCHAR
1489 config UCLIBC_HAS_STDIO_BUFSIZ_256
1490 bool "256 (minimum ANSI/ISO C99 value)"
1492 config UCLIBC_HAS_STDIO_BUFSIZ_512
1495 config UCLIBC_HAS_STDIO_BUFSIZ_1024
1498 config UCLIBC_HAS_STDIO_BUFSIZ_2048
1501 config UCLIBC_HAS_STDIO_BUFSIZ_4096
1504 config UCLIBC_HAS_STDIO_BUFSIZ_8192
1507 # If you add more choices, you will need to update uClibc_stdio.h.
1512 prompt "Stdio builtin buffer size (uClibc-specific)"
1513 depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
1514 default UCLIBC_HAS_STDIO_BUILTIN_BUFFER_NONE
1516 When a FILE is created with fopen(), an attempt is made to allocate
1517 a BUFSIZ buffer for it. If the allocation fails, fopen() will still
1518 succeed but the FILE will be unbuffered.
1520 This option adds a small amount of space to each FILE to act as an
1521 emergency buffer in the event of a buffer allocation failure.
1523 Most people will answer None.
1525 config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_NONE
1528 config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_4
1531 config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_8
1534 # If you add more choices, you will need to update uClibc_stdio.h.
1538 config UCLIBC_HAS_STDIO_SHUTDOWN_ON_ABORT
1539 bool "Attempt to shutdown stdio subsystem when abort() is called."
1542 ANSI/ISO C99 requires abort() to be asyn-signal-safe. So there was
1543 a behavioral change made in SUSv3. Previously, abort() was required
1544 to have the affect of fclose() on all open streams. The wording has
1545 been changed to "may" from "shall".
1547 Most people will answer N.
1549 config UCLIBC_HAS_STDIO_GETC_MACRO
1550 bool "Provide a macro version of getc()"
1551 depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
1554 Provide a macro version of getc().
1556 Most people will answer Y.
1558 config UCLIBC_HAS_STDIO_PUTC_MACRO
1559 bool "Provide a macro version of putc()"
1560 depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
1563 Provide a macro version of putc().
1565 Most people will answer Y.
1567 config UCLIBC_HAS_STDIO_AUTO_RW_TRANSITION
1568 bool "Support auto-r/w transition"
1571 Answer Y to enable the stdio subsystem to automaticly transition
1572 between reading and writing. This relaxes the ANSI/ISO C99
1575 When a file is opened with update mode ('+' as the second or third
1576 character in the list of mode argument values), both input and output
1577 may be performed on the associated stream. However, output shall not
1578 be directly followed by input without an intervening call to the
1579 fflush function or to a file positioning function (fseek, fsetpos,
1580 or rewind), and input shall not be directly followed by output without
1581 an intervening call to a file positioning function, unless the input
1582 operation encounters endÂofÂfile.
1584 Most people will answer Y.
1586 config UCLIBC_HAS_FOPEN_LARGEFILE_MODE
1587 bool "Support an fopen() 'F' flag for large file mode (uClibc-specific)"
1588 depends on UCLIBC_HAS_LFS
1591 Answer Y to enable a uClibc-specific extension to allow passing an
1592 additional 'F' flag in the mode string for fopen() to specify that
1593 the file should be open()ed with the O_LARGEFILE flag set.
1595 Most people will answer N.
1597 config UCLIBC_HAS_FOPEN_EXCLUSIVE_MODE
1598 bool "Support an fopen() 'x' flag for exclusive mode (glibc-compat)"
1601 Answer Y to support a glibc extension to allow passing
1602 additional 'x' flag in the mode string for fopen() to specify that
1603 the file should be open()ed with the O_EXCL flag set.
1605 Most people will answer N.
1607 config UCLIBC_HAS_GLIBC_CUSTOM_STREAMS
1608 bool "Support fmemopen(), open_memstream(), and fopencookie() (glibc-compat)"
1611 Answer Y to support the glibc 'custom stream' extension functions
1612 fmemopen(), open_memstream(), and fopencookie().
1614 NOTE: There are some minor differences regarding seeking behavior.
1616 Most people will answer N.
1618 config UCLIBC_HAS_PRINTF_M_SPEC
1619 bool "Support the '%m' specifier in printf format strings (glibc-compat)"
1622 Answer Y to support a glibc extension to interpret '%m' in printf
1623 format strings as an instruction to output the error message string
1624 (as generated by strerror) corresponding to the current value of
1627 Most people will answer N.
1629 config UCLIBC_HAS_ERRNO_MESSAGES
1630 bool "Include the errno message text in the library"
1633 Answer Y if you want to include the errno message text in the
1634 library. This adds about 3K to the library, but enables strerror()
1635 to generate text other than 'Unknown error <number>'.
1637 Most people will answer Y.
1639 config UCLIBC_HAS_SYS_ERRLIST
1640 bool "Support sys_errlist[] (obsolete-compat)"
1641 depends on UCLIBC_HAS_ERRNO_MESSAGES
1644 Answer Y if you want to support the obsolete sys_errlist[].
1645 This adds about 0.5k to the library, except for the mips
1646 arch where it adds over 4K.
1648 WARNING! In the future, support for sys_errlist[] may be unavailable
1649 in at least some configurations. In fact, it may be removed
1652 Most people will answer N.
1654 Application writers: use the strerror(3) function.
1656 config UCLIBC_HAS_SIGNUM_MESSAGES
1657 bool "Include the signum message text in the library"
1660 Answer Y if you want to include the signum message text in the
1661 library. This adds about 0.5K to the library, but enables strsignal()
1662 to generate text other than 'Unknown signal <number>'.
1664 Most people will answer Y.
1666 config UCLIBC_HAS_SYS_SIGLIST
1667 bool "Support sys_siglist[] (bsd-compat)"
1668 depends on UCLIBC_HAS_SIGNUM_MESSAGES
1671 Answer Y if you want to support sys_siglist[].
1673 WARNING! In the future, support for sys_siglist[] may be unavailable
1674 in at least some configurations. In fact, it may be removed
1677 Most people will answer N.
1679 config UCLIBC_HAS_GETTEXT_AWARENESS
1680 bool "Include gettext awareness"
1681 depends on UCLIBC_HAS_LOCALE && UCLIBC_MJN3_ONLY
1684 NOTE!!! Not yet integrated with strerror and strsignal. NOTE!!!
1686 Answer Y if you want to include weak stub gettext support and
1687 make the *strerror*() and strsignal() functions gettext-aware.
1689 Currently, to get functional gettext functionality you will need
1692 Most people will answer N.
1694 config UCLIBC_HAS_GNU_GETOPT
1695 bool "Support gnu getopt"
1698 Answer Y if you want to include full gnu getopt() instead of a
1699 (much smaller) SUSv3 compatible getopt().
1701 Most people will answer Y.
1703 config UCLIBC_HAS_STDIO_FUTEXES
1704 bool "Use futexes for multithreaded I/O locking"
1706 depends on UCLIBC_HAS_THREADS_NATIVE
1708 If you want to compile uClibc to use futexes for low-level
1709 I/O locking, answer Y. Otherwise, answer N.
1711 config UCLIBC_HAS_GETOPT_LONG
1712 bool "Support getopt_long/getopt_long_only"
1713 depends on !UCLIBC_HAS_GNU_GETOPT
1716 Answer Y if you want to include getopt_long[_only() used by many
1719 Most people will answer Y.
1721 config UCLIBC_HAS_GNU_GETSUBOPT
1722 bool "Support glibc getsubopt"
1725 Answer Y if you want to include glibc getsubopt() instead of a
1726 smaller SUSv3 compatible getsubopt().
1728 Most people will answer Y.
1734 config UCLIBC_HAS_REGEX
1735 bool "Regular Expression Support"
1738 POSIX regular expression code is really big -- 53k all by itself.
1739 If you don't use regular expressions, turn this off and save space.
1740 Of course, if you only statically link, leave this on, since it will
1741 only be included in your apps if you use regular expressions.
1743 config UCLIBC_HAS_REGEX_OLD
1744 bool "Use the older (stable) regular expression code"
1745 depends on UCLIBC_HAS_REGEX
1748 There are two versions of regex. The older (stable) version has
1749 been in uClibc for quite a long time but hasn't seen too many
1750 updates. It also has some known issues when dealing with uncommon
1751 corner cases and multibyte/unicode strings. However, it is quite
1752 a bit smaller than the newer version.
1754 If the older version has worked for you and you don't need unicode
1755 support, then stick with the old version (and say Y here).
1756 Otherwise, you should use the new version (and say N here).
1758 config UCLIBC_HAS_FNMATCH
1759 bool "fnmatch Support"
1764 config UCLIBC_HAS_FNMATCH_OLD
1765 bool "Use the older (stable) fnmatch code"
1766 depends on UCLIBC_HAS_FNMATCH
1769 There are two versions of fnmatch. The older (stable) version has
1770 been in uClibc for quite a long time but hasn't seen too many
1771 updates. It also has some known issues when dealing with uncommon
1772 corner cases and multibyte/unicode strings. However, it is quite
1773 a bit smaller than the newer version.
1775 If the older version has worked for you and you don't need unicode
1776 support, then stick with the old version (and say Y here).
1777 Otherwise, you should use the new version (and say N here).
1779 config UCLIBC_HAS_WORDEXP
1780 bool "Support the wordexp() interface"
1781 depends on UCLIBC_HAS_GLOB
1784 The SuSv3 wordexp() interface performs word expansions per the Shell
1785 and Utilities volume of IEEE Std 1003.1-2001, Section 2.6. It is
1786 intended for use by applications that want to implement all of the
1787 standard Bourne shell expansions on input data.
1789 This interface is rarely used, and very large. Unless you have a
1790 pressing need for wordexp(), you should probably answer N.
1792 config UCLIBC_HAS_NFTW
1793 bool "Support the nftw() interface"
1796 The SuSv3 nftw() interface is used to recursively descend
1797 directory paths while repeatedly calling a function.
1799 This interface is rarely used, and adds around 4.5k. Unless you have
1800 a pressing need for nftw(), you should probably answer N.
1802 config UCLIBC_HAS_FTW
1803 bool "Support the ftw() interface"
1805 depends on UCLIBC_SUSV4_LEGACY
1807 The SuSv3 ftw() interface is used to recursively descend
1808 directory paths while repeatedly calling a function.
1810 This interface is rarely used, and adds around 4.5k. Unless you have
1811 a pressing need for ftw(), you should probably answer N.
1814 config UCLIBC_HAS_GLOB
1815 bool "Support the glob() interface"
1816 depends on UCLIBC_HAS_FNMATCH
1820 The glob interface is somewhat large (weighing in at about 2,5k). It
1821 is used fairly often, but is an option since people wanting to go for
1822 absolute minimum size may wish to omit it.
1824 Most people will answer Y.
1826 config UCLIBC_HAS_GNU_GLOB
1827 bool "Support gnu glob() interface"
1828 depends on UCLIBC_HAS_GLOB
1831 The gnu glob interface is somewhat larger (weighing in at about 4,2k)
1832 than it's SuSv3 counterpart (and is out of date). It is an old copy
1833 from glibc and does not support all the GNU specific options.
1835 Answer Y if you want to include full gnu glob() instead of the smaller
1836 SUSv3 compatible glob().
1838 Most people will answer N.
1845 menu "Library Installation Options"
1847 config SHARED_LIB_LOADER_PREFIX
1848 string "Shared library loader path"
1849 depends on HAVE_SHARED
1850 default "$(RUNTIME_PREFIX)lib"
1852 When using shared libraries, this path is the location where the
1853 shared library will be invoked. This value will be compiled into
1854 every binary compiled with uClibc.
1856 For a typical target system this should be set to "/lib", such that
1857 'make install' will install /lib/ld-uClibc.so.0.
1860 If you do not have a shared library loader with the correct name
1861 sitting in the directory this points to, your binaries will not
1864 config RUNTIME_PREFIX
1865 string "uClibc runtime library directory"
1866 default "/usr/$(TARGET_ARCH)-linux-uclibc/"
1868 RUNTIME_PREFIX is the directory into which the uClibc runtime
1869 libraries will be installed. The result will look something
1872 lib/ <contains all runtime libraries>
1873 usr/bin/ldd <the ldd utility program>
1874 sbin/ldconfig <the ldconfig utility program>
1875 This value is used by the 'make install' Makefile target. Since this
1876 directory is compiled into the shared library loader, you will need to
1877 recompile uClibc if you change this value...
1879 For a typical target system this should be set to "/", such that
1880 'make install' will install /lib/libuClibc-<VERSION>.so
1883 string "uClibc development environment directory"
1884 default "/usr/$(TARGET_ARCH)-linux-uclibc/usr/"
1886 DEVEL_PREFIX is the directory into which the uClibc development
1887 environment will be installed. The result will look something
1890 lib/ <contains static libs>
1891 include/ <Where all the header files go>
1892 This value is used by the 'make install' Makefile target when
1893 installing a uClibc development environment.
1895 For a typical target system this should be set to "/usr", such that
1896 'make install' will install /usr/include/<header files>.
1898 config HARDWIRED_ABSPATH
1899 bool "Hardwire absolute paths into linker scripts"
1902 This prepends absolute paths to the libraries mentioned in linker
1903 scripts such as libc.so.
1905 This is a build time optimization. It has no impact on dynamic
1906 linking at runtime, which doesn't use linker scripts.
1908 You must disable this to use uClibc with a relocatable toolchain,
1909 such as the prebuilt binary cross compilers at
1910 http://uclibc.org/downloads/binaries which may be installed at an
1911 arbitrary location (such as in a user's home directory).
1913 The amount of time saved by this optimization is actually too small to
1914 measure. The linker just had to search the library path to find the
1915 linker script, so the dentries are cache hot if it has to search the
1916 same path again. But it's what glibc does, so we do it too.
1921 menu "Security options"
1923 config UCLIBC_BUILD_PIE
1924 bool "Build utilities as ET_DYN/PIE executables"
1925 depends on HAVE_SHARED
1926 depends on TARGET_arm || TARGET_frv || TARGET_i386 || TARGET_mips || TARGET_powerpc
1927 select FORCE_SHAREABLE_TEXT_SEGMENTS
1930 If you answer Y here, ldd and iconv are built as ET_DYN/PIE
1933 It requires gcc-3.4 and binutils-2.15 (for arm 2.16) or later.
1934 More about ET_DYN/PIE binaries on <http://pax.grsecurity.net/> .
1936 WARNING: This option also enables FORCE_SHAREABLE_TEXT_SEGMENTS, so
1937 all libraries have to be built with -fPIC or -fpic, and all
1938 assembler functions must be written as position independent
1941 config UCLIBC_HAS_ARC4RANDOM
1942 bool "Include the arc4random() function"
1945 Answer Y to support the OpenBSD-like arc4random() function. This
1946 function picks a random number between 0 and N, and will always return
1947 something even if the random driver is dead. If urandom fails then
1948 gettimeofday(2) will be used as the random seed. This function is
1949 designed to be more dependable than invoking /dev/urandom directly.
1950 OpenSSL and OpenNTPD currently support this function.
1952 Most people will answer N.
1958 config UCLIBC_HAS_SSP
1959 bool "Support for GCC stack smashing protector"
1960 depends on !HAVE_NO_SSP
1963 Add code to support GCC's -fstack-protector[-all] option to uClibc.
1964 This requires GCC 4.1 or newer. GCC does not have to provide libssp,
1965 the needed functions are added to ldso/libc instead.
1967 GCC's stack protector is a reimplementation of IBM's propolice.
1968 See http://www.trl.ibm.com/projects/security/ssp/ and
1969 http://www.linuxfromscratch.org/hints/downloads/files/ssp.txt
1972 Note that NOEXECSTACK on a kernel with address space randomization
1973 is generally sufficient to prevent most buffer overflow exploits
1974 without increasing code size. This option essentially adds debugging
1977 Most people will answer N.
1979 config UCLIBC_HAS_SSP_COMPAT
1980 bool "Support for gcc-3.x propolice smashing stack protector"
1981 depends on UCLIBC_HAS_SSP
1984 Add gcc-3.x propolice smashing stack protector to the library.
1986 This requires a patched version of GCC, supporting the
1987 -fstack-protector[-all] options, with the __guard and
1988 __stack_smash_handler functions removed from libgcc.
1989 These functions are added to ldso/libc instead.
1991 More information at:
1992 <http://www.research.ibm.com/trl/projects/security/ssp/>
1994 Most people will answer N.
1996 config SSP_QUICK_CANARY
1997 bool "Use simple guard values without accessing /dev/urandom"
1998 depends on UCLIBC_HAS_SSP
2001 Use gettimeofday(2) to define the __guard without accessing
2003 WARNING: This makes smashing stack protector vulnerable to timing
2005 Most people will answer N.
2008 prompt "Propolice protection blocking signal"
2009 depends on UCLIBC_HAS_SSP
2010 default PROPOLICE_BLOCK_ABRT if ! DODEBUG
2011 default PROPOLICE_BLOCK_SEGV if DODEBUG
2013 "abort" use SIGABRT to block offending programs.
2014 This is the default implementation.
2016 "segfault" use SIGSEGV to block offending programs.
2017 Use this for debugging.
2019 If unsure, answer "abort".
2021 config PROPOLICE_BLOCK_ABRT
2024 config PROPOLICE_BLOCK_SEGV
2029 config UCLIBC_BUILD_SSP
2030 bool "Build uClibc with -fstack-protector"
2031 depends on UCLIBC_HAS_SSP
2034 Build all uClibc libraries and executables with -fstack-protector,
2035 adding extra stack overflow checking to most uClibc functions.
2037 config UCLIBC_BUILD_RELRO
2038 bool "Build uClibc with linker option -z RELRO"
2039 depends on HAVE_SHARED
2042 Build all libraries and executables with "ld -z relro".
2044 This tells the linker to mark chunks of an executable or shared
2045 library read-only after applying dynamic relocations. (This comes
2046 up when a global const variable is initialized to the address of a
2047 function or the value of another global variable.)
2049 This is a fairly obscure option the ld man page doesn't even bother
2050 to document properly. It's a security paranoia issue that's more
2051 likely to consume memory (by allocating an extra page) rather than
2054 This is explained in more depth at
2055 http://www.airs.com/blog/archives/189
2057 Nobody is likely to care whether you say Y or N here.
2059 config UCLIBC_BUILD_NOW
2060 bool "Build uClibc with linker option -z NOW"
2061 depends on HAVE_SHARED
2064 Build all libraries and executables with "ld -z now".
2066 This tells the linker to resolve all symbols when the library is
2067 first loaded, rather than when each function is first called. This
2068 increases start-up latency by a few microseconds and may do
2069 unnecessary work (resolving symbols that are never used), but the
2070 realtime people like it for making microbenchmark timings slightly
2071 more predictable and in some cases it can be slightly faster due to
2072 CPU cache behavior (not having to fault the linker back in to do
2073 lazy symbol resolution).
2075 Most people can't tell the difference between selecting Y or N here.
2077 config UCLIBC_BUILD_NOEXECSTACK
2078 bool "Build uClibc with noexecstack marking"
2081 Mark all assembler files as noexecstack, which will mark uClibc
2082 as not requiring an executable stack. (This doesn't prevent other
2083 files you link against from claiming to need an executable stack, it
2084 just won't cause uClibc to request it unnecessarily.)
2086 This is a security thing to make buffer overflows harder to exploit.
2087 By itself, it's kind of useless, as Linus Torvalds explained in 1998:
2088 http://old.lwn.net/1998/0806/a/linus-noexec.html
2090 It only actually provides any security when combined with address
2091 space randomization, explained here: http://lwn.net/Articles/121845/
2093 Address space randomization is on by default in current linux
2094 kernels (although it can be disabled using the option
2097 You should probably say Y.
2101 menu "uClibc development/debugging options"
2103 config CROSS_COMPILER_PREFIX
2104 string "Cross-compiling toolchain prefix"
2107 The prefix used to execute your cross-compiling toolchain. For
2108 example, if you run 'arm-linux-uclibc-gcc' to compile something,
2109 then enter 'arm-linux-uclibc-' here.
2111 config UCLIBC_EXTRA_CFLAGS
2112 string "Enter any extra CFLAGS to use to build uClibc"
2115 Add any additional CFLAGS to be used to build uClibc.
2118 bool "Build uClibc with debugging symbols"
2120 select EXTRA_WARNINGS
2122 Say Y here if you wish to compile uClibc with debugging symbols.
2123 This will allow you to use a debugger to examine uClibc internals
2124 while applications are running. This increases the size of the
2125 library considerably and should only be used when doing development.
2126 If you are doing development and want to debug uClibc, answer Y.
2128 Otherwise, answer N.
2131 bool "Build pthread with debugging output"
2132 depends on UCLIBC_HAS_THREADS && LINUXTHREADS_OLD
2135 Enable debug output in libpthread. This is only useful when doing
2136 development in libpthread itself.
2138 Otherwise, answer N.
2141 bool "Strip libraries and executables"
2145 Say Y here if you do wish to strip all uClibc libraries and
2146 executables. No stripping increases the size of the binaries
2147 considerably, but makes it possible to debug uClibc libraries.
2148 Most people will answer Y.
2151 bool "Build uClibc with run-time assertion testing"
2154 Say Y here to include runtime assertion tests.
2155 This enables runtime assertion testing in some code, which can
2156 increase the size of the library and incur runtime overhead.
2157 If you say N, then this testing will be disabled.
2159 config SUPPORT_LD_DEBUG
2160 bool "Build the shared library loader with debugging support"
2161 depends on HAVE_SHARED
2164 Answer Y here to enable all the extra code needed to debug the uClibc
2165 native shared library loader. The level of debugging noise that is
2166 generated depends on the LD_DEBUG environment variable... Just set
2167 LD_DEBUG to something like: 'LD_DEBUG=token1,token2,.. prog' to
2168 debug your application. Diagnostic messages will then be printed to
2171 For now these debugging tokens are available:
2172 detail provide more information for some options
2173 move display copy processing
2174 symbols display symbol table processing
2175 reloc display relocation processing; detail shows the
2177 nofixups never fixes up jump relocations
2178 bindings displays the resolve processing (function calls);
2179 detail shows the relocation patch
2180 all Enable everything!
2182 The additional environment variable:
2183 LD_DEBUG_OUTPUT=file
2184 redirects the diagnostics to an output file created using
2185 the specified name and the process id as a suffix.
2187 An excellent start is simply:
2188 $ LD_DEBUG=binding,move,symbols,reloc,detail ./appname
2189 or to log everything to a file named 'logfile', try this
2190 $ LD_DEBUG=all LD_DEBUG_OUTPUT=logfile ./appname
2192 If you are doing development and want to debug uClibc's shared library
2193 loader, answer Y. Mere mortals answer N.
2195 config SUPPORT_LD_DEBUG_EARLY
2196 bool "Build the shared library loader with early debugging support"
2197 depends on HAVE_SHARED
2200 Answer Y here to if you find the uClibc shared library loader is
2201 crashing or otherwise not working very early on. This is typical
2202 only when starting a new port when you haven't figured out how to
2203 properly get the values for argc, argv, environ, etc. This method
2204 allows a degree of visibility into the very early shared library
2205 loader initialization process. If you are doing development and want
2206 to debug the uClibc shared library loader early initialization,
2207 answer Y. Mere mortals answer N.
2209 config UCLIBC_MALLOC_DEBUGGING
2210 bool "Build malloc with debugging support"
2211 depends on MALLOC || MALLOC_STANDARD
2214 Answer Y here to compile extra debugging support code into malloc.
2215 Malloc debugging output may then be enabled at runtime using the
2216 MALLOC_DEBUG environment variable.
2218 The value of MALLOC_DEBUG should be an integer, which is interpreted
2219 as a bitmask with the following bits:
2220 1 - do extra consistency checking
2221 2 - output messages for malloc/free calls and OS
2223 4 - output messages for the `MMB' layer
2224 8 - output messages for internal malloc heap manipulation
2227 Because this increases the size of malloc appreciably (due to strings
2228 etc), you should say N unless you need to debug a malloc problem.
2231 string "Compiler Warnings"
2234 Set this to the set of gcc warnings you wish to see while compiling.
2236 config EXTRA_WARNINGS
2237 bool "Enable extra annoying warnings"
2240 If you wish to build with extra warnings enabled, say Y here.
2243 bool "Compile all sources at once into an object"
2246 Set this to compile all sources at once into an object (IMA).
2247 This mode of compilation uses alot of memory but may produce
2250 Note that you need a very recent GCC for this to work, like
2251 gcc >= 4.3 plus eventually some patches.
2253 If unsure, keep the default of N.
2255 config UCLIBC_MJN3_ONLY
2256 bool "Manuel's hidden warnings"
2259 Answer Y here to see all Manuel's personal notes, warnings, and todos.
2261 Most people will answer N.
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