2 # For a description of the syntax of this configuration file,
3 # see extra/config/Kconfig-language.txt
6 mainmenu "uClibc $VERSION C Library Configuration"
8 config DESIRED_TARGET_ARCH
17 prompt "Target Architecture"
18 default TARGET_alpha if DESIRED_TARGET_ARCH = "alpha"
19 default TARGET_arm if DESIRED_TARGET_ARCH = "arm"
20 default TARGET_avr32 if DESIRED_TARGET_ARCH = "avr32"
21 default TARGET_bfin if DESIRED_TARGET_ARCH = "bfin"
22 default TARGET_cris if DESIRED_TARGET_ARCH = "cris"
23 default TARGET_e1 if DESIRED_TARGET_ARCH = "e1"
24 default TARGET_frv if DESIRED_TARGET_ARCH = "frv"
25 default TARGET_h8300 if DESIRED_TARGET_ARCH = "h8300"
26 default TARGET_hppa if DESIRED_TARGET_ARCH = "hppa"
27 default TARGET_i386 if DESIRED_TARGET_ARCH = "i386"
28 default TARGET_i960 if DESIRED_TARGET_ARCH = "i960"
29 default TARGET_ia64 if DESIRED_TARGET_ARCH = "ia64"
30 default TARGET_m68k if DESIRED_TARGET_ARCH = "m68k"
31 default TARGET_metag if DESIRED_TARGET_ARCH = "metag"
32 default TARGET_microblaze if DESIRED_TARGET_ARCH = "microblaze"
33 default TARGET_mips if DESIRED_TARGET_ARCH = "mips"
34 default TARGET_nios if DESIRED_TARGET_ARCH = "nios"
35 default TARGET_nios2 if DESIRED_TARGET_ARCH = "nios2"
36 default TARGET_powerpc if DESIRED_TARGET_ARCH = "powerpc"
37 default TARGET_sh if DESIRED_TARGET_ARCH = "sh"
38 default TARGET_sh64 if DESIRED_TARGET_ARCH = "sh64"
39 default TARGET_sparc if DESIRED_TARGET_ARCH = "sparc"
40 default TARGET_v850 if DESIRED_TARGET_ARCH = "v850"
41 default TARGET_vax if DESIRED_TARGET_ARCH = "vax"
42 default TARGET_x86_64 if DESIRED_TARGET_ARCH = "x86_64"
43 default TARGET_xtensa if DESIRED_TARGET_ARCH = "xtensa"
45 The architecture of your target.
92 config TARGET_microblaze
104 config TARGET_powerpc
131 menu "Target Architecture Features and Options"
134 source "extra/Configs/Config.alpha"
138 source "extra/Configs/Config.arm"
142 source "extra/Configs/Config.avr32"
146 source "extra/Configs/Config.bfin"
150 source "extra/Configs/Config.cris"
154 source "extra/Configs/Config.e1"
158 source "extra/Configs/Config.frv"
162 source "extra/Configs/Config.h8300"
166 source "extra/Configs/Config.hppa"
170 source "extra/Configs/Config.i386"
174 source "extra/Configs/Config.i960"
178 source "extra/Configs/Config.ia64"
182 source "extra/Configs/Config.m68k"
186 source "extra/Configs/Config.metag"
190 source "extra/Configs/Config.nios"
194 source "extra/Configs/Config.nios2"
198 source "extra/Configs/Config.microblaze"
202 source "extra/Configs/Config.mips"
206 source "extra/Configs/Config.powerpc"
210 source "extra/Configs/Config.sh"
214 source "extra/Configs/Config.sh64"
218 source "extra/Configs/Config.sparc"
222 source "extra/Configs/Config.v850"
226 source "extra/Configs/Config.vax"
230 source "extra/Configs/Config.x86_64"
234 source "extra/Configs/Config.xtensa"
238 source "extra/Configs/Config.c6x"
241 config TARGET_SUBARCH
243 default "e500" if CONFIG_E500
244 default "classic" if CONFIG_CLASSIC
245 default "sh4" if CONFIG_SH4
246 default "" if CONFIG_386
247 default "i486" if CONFIG_486
248 default "i586" if CONFIG_586
249 default "i686" if CONFIG_686
252 source "extra/Configs/Config.in.arch"
256 menu "General Library Settings"
262 bool "Generate only Position Independent Code (PIC)"
264 depends on !HAVE_NO_PIC
266 If you wish to build all of uClibc as PIC objects, then answer Y here.
267 If you are unsure, then you should answer N.
269 config ARCH_HAS_NO_SHARED
272 config ARCH_HAS_NO_LDSO
274 select ARCH_HAS_NO_SHARED
276 config ARCH_HAS_UCONTEXT
280 bool "Enable shared libraries"
281 depends on !ARCH_HAS_NO_SHARED
284 If you wish to build uClibc with support for shared libraries then
285 answer Y here. If you only want to build uClibc as a static library,
288 config FORCE_SHAREABLE_TEXT_SEGMENTS
289 bool "Only load shared libraries which can share their text segment"
290 depends on HAVE_SHARED
293 If you answer Y here, the uClibc native shared library loader will
294 only load shared libraries, which do not need to modify any
295 non-writable segments. These libraries haven't set the DT_TEXTREL
296 tag in the dynamic section (==> objdump).
297 All your libraries must be compiled with -fPIC or -fpic, and all
298 assembler function must be written as position independent code (PIC).
299 Enabling this option will make uClibc's shared library loader a
300 little bit smaller and guarantee that no memory will be wasted by
301 badly coded shared libraries.
303 config LDSO_LDD_SUPPORT
304 bool "Native 'ldd' support"
305 depends on HAVE_SHARED
308 Enable all the code needed to support traditional ldd,
309 which executes the shared library loader to resolve all dependencies
310 and then provide a list of shared libraries that are required for an
311 application to function. Disabling this option will make uClibc's
312 shared library loader a little bit smaller.
313 Most people will answer Y.
315 config LDSO_CACHE_SUPPORT
316 bool "Enable library loader cache (ld.so.conf)"
317 depends on HAVE_SHARED
320 Enable this to make use of /etc/ld.so.conf, the shared library loader
321 cache configuration file to support for non-standard library paths.
322 After updating this file, it is necessary to run 'ldconfig' to update
323 the /etc/ld.so.cache shared library loader cache file.
325 config LDSO_PRELOAD_ENV_SUPPORT
326 bool "Enable library loader LD_PRELOAD environment"
327 depends on HAVE_SHARED
330 Enable this to make use of LD_PRELOAD environment variable.
331 A whitespace-separated list of additional, user-specified, ELF shared
332 libraries to be loaded before all others. This can be used to
333 selectively override functions in other shared libraries. For
334 set-user-ID/set-group-ID ELF binaries, only libraries in the standard
335 search directories that are also set-user-ID will be loaded.
337 config LDSO_PRELOAD_FILE_SUPPORT
338 bool "Enable library loader preload file (ld.so.preload)"
339 depends on HAVE_SHARED
341 Enable this to make use of /etc/ld.so.preload. This file contains a
342 whitespace separated list of shared libraries to be loaded before
345 config LDSO_BASE_FILENAME
346 string "Shared library loader naming prefix"
347 depends on HAVE_SHARED && (LDSO_CACHE_SUPPORT || LDSO_PRELOAD_FILE_SUPPORT)
350 If you wish to support both uClibc and glibc on the same system, it
351 is necessary to set this to something other than "ld.so" to avoid
352 conflicts with glibc, which also uses "ld.so". This prevents both
353 libraries from using the same /etc/ld.so.* files. If you wish to
354 support both uClibc and glibc on the same system then you should set
355 this to "ld-uClibc.so".
357 Most people will leave this set to the default of "ld.so".
359 WARNING: Changing the default prefix could cause problems with
362 config LDSO_STANDALONE_SUPPORT
363 bool "Dynamic linker stand-alone mode support"
364 depends on HAVE_SHARED
366 The dynamic linker can be run either indirectly through running some
367 dynamically linked program or library (in which case no command line
368 options to the dynamic linker can be passed and, in the ELF case, the
369 dynamic linker which is stored in the .interp section of the program
370 is executed) or directly by running:
372 /lib/ld-uClibc.so.* [OPTIONS] [PROGRAM [ARGUMENTS]]
374 Stand-alone execution is a prerequisite for adding prelink
375 capabilities to uClibc dynamic linker, as well useful for testing an
376 updated version of the dynamic linker without breaking the system.
378 config LDSO_PRELINK_SUPPORT
379 bool "Dynamic linker prelink support"
380 depends on HAVE_SHARED
381 select LDSO_STANDALONE_SUPPORT
383 The dynamic linker can be used in stand-alone mode by the prelink tool
384 for prelinking ELF shared libraries and binaries to speed up startup
385 time. It also is able to load and handle prelinked libraries and
388 config UCLIBC_STATIC_LDCONFIG
389 bool "Link ldconfig statically"
390 depends on HAVE_SHARED
393 Enable this option to statically link the ldconfig binary.
395 Making ldconfig static can be beneficial if you have a library
396 problem and need to use ldconfig to recover. Sometimes it is
397 preferable to instead keep the size of the system down, in which
398 case you should disable this option.
401 bool "Enable ELF RUNPATH tag support"
402 depends on HAVE_SHARED
403 default y if LDSO_CACHE_SUPPORT
405 ELF's may have dynamic RPATH/RUNPATH tags. These tags list paths
406 which extend the library search paths. They are really only useful
407 if a package installs libraries in non standard locations and
408 ld.so.conf support is disabled.
410 Usage of RUNPATH tags is not too common, so disabling this feature
411 should be safe for most people.
413 config LDSO_SAFE_RUNPATH
414 bool "Allow only RUNPATH beginning with /"
415 depends on LDSO_RUNPATH
418 Allow only absolute path in RPATH/RUNPATH.
420 config LDSO_SEARCH_INTERP_PATH
421 bool "Add ldso path to lib search path"
422 depends on HAVE_SHARED
425 The ldso is told where it is being executed from and can use that
426 path to find related core libraries. This is useful by default,
427 but can be annoying in a mixed development environment.
429 i.e. if the ldso is run from /foo/boo/ldso.so, it will start its
430 library search with /foo/boo/
432 If unsure, simply say Y here.
434 config LDSO_LD_LIBRARY_PATH
435 bool "Add LD_LIBRARY_PATH to lib search path"
436 depends on HAVE_SHARED
439 On hardened system it could be useful to disable the use of
440 LD_LIBRARY_PATH environment variable (a colon-separated list of
441 directories in which to search for ELF libraries at execution-time).
443 If unsure, simply say Y here.
445 config LDSO_NO_CLEANUP
446 bool "Disable automatic unloading of dynamically loaded shared objects"
447 depends on HAVE_SHARED
449 If you need complete allocation traces when debugging memory leaks
450 using Valgrind in a process that dynamically loads shared objects,
451 then answer Y here. Unlike glibc, uClibc unloads all dynamically
452 loaded shared objects when a process exits, which prevents Valgrind
453 from correctly resolving the symbols from the unloaded shared objects.
454 Unless you know you need this, you should answer N.
456 config UCLIBC_CTOR_DTOR
457 bool "Support global constructors and destructors"
460 If you wish to build uClibc with support for global constructor
461 (ctor) and global destructor (dtor) support, then answer Y here.
462 When ctor/dtor support is enabled, binaries linked with uClibc must
463 also be linked with crtbegin.o and crtend.o which are provided by gcc
464 (the "*startfile:" and "*endfile:" settings in your gcc specs file
465 may need to be adjusted to include these files). This support will
466 also add a small amount of additional size to each binary compiled vs
467 uClibc. If you will be using uClibc with C++, or if you need the gcc
468 __attribute__((constructor)) and __attribute__((destructor)) to work,
469 then you definitely want to answer Y here. If you don't need ctors
470 or dtors and want your binaries to be as small as possible, then
473 config LDSO_GNU_HASH_SUPPORT
474 bool "Enable GNU hash style support"
475 depends on HAVE_SHARED
477 Newest binutils support a new hash style named GNU-hash. The dynamic
478 linker will use the new GNU-hash section (.gnu.hash) for symbol lookup
479 if present into the ELF binaries, otherwise it will use the old SysV
480 hash style (.hash). This ensures that it is completely backward
482 Further, being the hash table implementation self-contained into each
483 executable and shared libraries, objects with mixed hash style can
484 peacefully coexist in the same process.
486 If you want to use this new feature, answer Y
489 prompt "Thread support"
490 #default UCLIBC_HAS_THREADS_NATIVE if (TARGET_alpha || TARGET_arm || TARGET_i386 || TARGET_mips || TARGET_powerpc || TARGET_sh || TARGET_sh64)
491 default HAS_NO_THREADS
493 If you want to compile uClibc with pthread support, then answer Y.
494 This will increase the size of uClibc by adding a bunch of locking
495 to critical data structures, and adding extra code to ensure that
496 functions are properly reentrant.
498 config HAS_NO_THREADS
501 Disable thread support.
503 config LINUXTHREADS_OLD
504 bool "older (stable) version of linuxthreads"
505 # linuxthreads and linuxthreads.old need nanosleep()
506 select UCLIBC_HAS_REALTIME
508 There are two versions of linuxthreads. The older (stable) version
509 has been in uClibc for quite a long time but hasn't seen too many
510 updates other than bugfixes.
513 config LINUXTHREADS_NEW
514 bool "slightly newer version of linuxthreads"
515 depends on ARCH_HAS_DEPRECATED_SYSCALLS
517 The new version has not been tested much, and lacks ports for arches
518 which glibc does not support (like bfin/frv/etc...), but is based on
519 the latest code from glibc, so it may be the only choice for the
520 newer ports (like alpha/amd64/64bit arches and hppa).
522 config UCLIBC_HAS_THREADS_NATIVE
523 bool "Native POSIX Threading (NPTL)"
524 select UCLIBC_HAS_TLS
525 select UCLIBC_HAS_STDIO_FUTEXES
526 select UCLIBC_HAS_REALTIME
527 # i386 has no lowlevellock support (yet) as opposed to i486 onward
528 depends on !CONFIG_386
530 If you want to compile uClibc with NPTL support, then answer Y.
532 IMPORTANT NOTE! NPTL requires a Linux 2.6 kernel, binutils
533 at least version 2.16 and GCC with at least version 4.1.0. NPTL
534 will not work with older versions of any above sources. If you
535 ignore any of these guidelines, you do so at your own risk. Do
536 not ask for help on any of the development mailing lists.
538 !!!! WARNING !!!! BIG FAT WARNING !!!! REALLY BIG FAT WARNING !!!!
540 This is experimental code and at times it may not even build and
541 even if it does it might decide to do random damage. This code is
542 potentially hazardous to your health and sanity. It will remain
543 that way until further notice at which point this notice will
544 disappear. Thank you for your support and for not smoking.
548 config UCLIBC_HAS_THREADS
549 def_bool y if !HAS_NO_THREADS
551 config UCLIBC_HAS_TLS
552 bool "Thread-Local Storage"
553 depends on UCLIBC_HAS_THREADS_NATIVE
555 If you want to enable TLS support then answer Y.
556 This is fast an efficient way to store per-thread local data
557 which is not on stack. It needs __thread support enabled in
560 config PTHREADS_DEBUG_SUPPORT
561 bool "Build pthreads debugging support"
562 depends on UCLIBC_HAS_THREADS
564 Say Y here if you wish to be able to debug applications that use
565 uClibc's pthreads library. By enabling this option, a library
566 named libthread_db will be built. This library will be dlopen()'d
567 by gdb and will allow gdb to debug the threads in your application.
569 IMPORTANT NOTE! Because gdb must dlopen() the libthread_db library,
570 you must compile gdb with uClibc in order for pthread debugging to
573 If you are doing development and want to debug applications using
574 uClibc's pthread library, answer Y. Otherwise, answer N.
577 config UCLIBC_HAS_SYSLOG
578 bool "Syslog support"
580 depends on UCLIBC_HAS_NETWORK_SUPPORT
581 select UCLIBC_HAS_SOCKET
583 Support sending messages to the system logger.
584 This requires socket-support.
586 config UCLIBC_HAS_LFS
587 bool "Large File Support"
590 If you wish to build uClibc with support for accessing large files
591 (i.e. files greater then 2 GiB) then answer Y. Do not enable this
592 if you are using an older Linux kernel (2.0.x) that lacks large file
593 support. Enabling this option will increase the size of uClibc.
596 prompt "Malloc Implementation"
597 default MALLOC if ! ARCH_USE_MMU
598 default MALLOC_STANDARD if ARCH_USE_MMU
603 "malloc" use mmap for all allocations and so works very well on
604 MMU-less systems that do not support the brk() system call. It is
605 pretty smart about reusing already allocated memory, and minimizing
607 This is the default for uClinux MMU-less systems.
612 "malloc-simple" is trivially simple and slow as molasses. It
613 was written from scratch for uClibc, and is the simplest possible
614 (and therefore smallest) malloc implementation.
616 This uses only the mmap() system call to allocate and free memory,
617 and does not use the brk() system call at all, making it a fine
618 choice for MMU-less systems with very limited memory. It's 100%
619 standards compliant, thread safe, very small, and releases freed
620 memory back to the OS immediately rather than keeping it in the
621 process's heap for reallocation. It is also VERY SLOW.
623 config MALLOC_STANDARD
624 bool "malloc-standard"
625 depends on ARCH_USE_MMU
627 "malloc-standard" is derived from the public domain dlmalloc
628 implementation by Doug Lea. It is quite fast, and is pretty smart
629 about reusing already allocated memory, and minimizing memory
630 wastage. This uses brk() for small allocations, while using mmap()
631 for larger allocations. This is the default malloc implementation
634 If unsure, answer "malloc-standard".
638 config MALLOC_GLIBC_COMPAT
639 bool "Malloc returns live pointer for malloc(0)"
641 The behavior of malloc(0) is listed as implementation-defined by
642 SuSv3. Glibc returns a valid pointer to something, while uClibc
643 normally returns NULL. I personally feel glibc's behavior is
644 not particularly safe, and allows buggy applications to hide very
647 When this option is enabled, uClibc will act just like glibc, and
648 return a live pointer when someone calls malloc(0). This pointer
649 provides a malloc'ed area with a size of 1 byte. This feature is
650 mostly useful when dealing with applications using autoconf's broken
651 AC_FUNC_MALLOC macro (which redefines malloc as rpl_malloc if it
652 does not detect glibc style returning-a-valid-pointer-for-malloc(0)
653 behavior). Most people can safely answer N.
655 config UCLIBC_HAS_OBSTACK
656 bool "Obstack Support (gnu extension)"
658 When this option is enabled, uClibc will provide support for obstacks.
659 An obstack is a structure in which memory can be dynamically allocated
660 as a 'stack of objects'. Many programs need this GNU extention and
661 you should say Y if you are using any. Otherwise, say N to save some
664 config UCLIBC_DYNAMIC_ATEXIT
665 bool "Dynamic atexit() Support"
668 When this option is enabled, uClibc will support an infinite number,
669 of atexit() and on_exit() functions, limited only by your available
670 memory. This can be important when uClibc is used with C++, since
671 global destructors are implemented via atexit(), and it is quite
672 possible to exceed the default number when this option is disabled.
673 Enabling this option adds a few bytes, and more significantly makes
674 atexit and on_exit depend on malloc, which can be bad when compiling
677 Unless you use uClibc with C++, you should probably answer N.
680 bool "Old (visible) atexit Support"
682 Enable this option if you want to update from 0.9.28 to git/0.9.29,
683 else you will be missing atexit() until you rebuild all apps.
685 config UCLIBC_SUSV2_LEGACY
686 bool "Enable SuSv2 LEGACY functions"
688 Enable this option if you want to have SuSv2 LEGACY functions
689 Currently applies to:
693 WARNING! ABI incompatibility.
695 config UCLIBC_SUSV3_LEGACY
696 bool "Enable SuSv3 LEGACY functions"
702 Enable this option if you want to have SuSv3 LEGACY functions
703 in the library, else they are replaced by SuSv3 proposed macros.
704 Currently applies to:
706 bcmp, bcopy, bzero, index, rindex, ftime,
707 bsd_signal, (ecvt), (fcvt), gcvt, (getcontext),
708 (getwd), (makecontext),
709 mktemp, (pthread_attr_getstackaddr), (pthread_attr_setstackaddr),
710 scalb, (setcontext), (swapcontext), ualarm, usleep,
713 WARNING! ABI incompatibility.
715 config UCLIBC_HAS_CONTEXT_FUNCS
716 bool "Use obsolescent context control functions"
717 depends on UCLIBC_SUSV3_LEGACY && ARCH_HAS_UCONTEXT
719 Add into library the SuSv3 obsolescent functions used for context
720 control. The setcontext family allows the implementation in C of
721 advanced control flow patterns such as iterators, fibers, and
722 coroutines. They may be viewed as an advanced version of
723 setjmp/longjmp; whereas the latter allows only a single non-local jump
724 up the stack, setcontext allows the creation of multiple cooperative
725 threads of control, each with its own stack.
726 These functions are: setcontext, getcontext, makecontext, swapcontext.
728 config UCLIBC_SUSV3_LEGACY_MACROS
729 bool "Enable SuSv3 LEGACY macros"
731 Enable this option if you want to have SuSv3 LEGACY macros.
732 Currently applies to bcopy/bzero/bcmp/index/rindex et al.
733 WARNING! ABI incompatibility.
735 config UCLIBC_SUSV4_LEGACY
736 bool "Enable SuSv4 LEGACY or obsolescent functions"
738 Enable this option if you want to have SuSv4 LEGACY functions
739 and macros in the library.
740 Currently applies to:
743 _longjmp, _setjmp, _tolower, _toupper, ftw, getitimer,
744 gettimeofday, isascii, pthread_getconcurrency,
745 pthread_setconcurrency, setitimer, setpgrp, sighold,
746 sigignore, sigpause, sigrelse, sigset, siginterrupt,
747 tempnam, toascii, ulimit.
750 asctime, asctime_r, ctime, ctime_r, gets, rand_r,
753 WARNING! ABI incompatibility.
755 config UCLIBC_STRICT_HEADERS
756 bool "Hide structures and constants for unsupported features"
758 Hide structures and constants in headers that should not be used,
759 because the respective feature is disabled.
761 WARNING! enabling this option requires to patch many faulty apps,
762 since they make (wrongly) use of these structures/constants,
763 although the feature was disabled.
765 config UCLIBC_HAS_STUBS
766 bool "Provide stubs for unavailable functionality"
768 With this option uClibc provides non-functional stubs for
769 functions which are impossible to implement on the target
770 architecture. Otherwise, such functions are simply omitted.
772 config UCLIBC_HAS_SHADOW
773 bool "Shadow Password Support"
776 Answer N if you do not need shadow password support.
777 Most people will answer Y.
779 config UCLIBC_HAS_PROGRAM_INVOCATION_NAME
780 bool "Support for program_invocation_name"
782 Support for the GNU-specific program_invocation_name and
783 program_invocation_short_name strings. Some GNU packages
784 (like tar and coreutils) utilize these for extra useful
785 output, but in general are not required.
787 At startup, these external strings are automatically set
788 up based on the value of ARGV[0].
790 If unsure, just answer N.
792 config UCLIBC_HAS___PROGNAME
793 bool "Support for __progname"
796 Some packages (like openssh) like to peek into internal libc
797 symbols to make their output a bit more user friendly.
799 At startup, __progname is automatically set up based on the
802 If unsure, just answer N.
804 config UCLIBC_HAS_PTY
805 bool "Support for pseudo-terminals"
808 This enables support for pseudo-terminals (see man 4 pts
811 If unsure, just answer Y.
814 bool "Assume that /dev/pts is a devpts or devfs file system"
816 depends on UCLIBC_HAS_PTY
818 Enable this if /dev/pts is on a devpts or devfs filesystem. Both
819 these filesystems automatically manage permissions on the /dev/pts
820 devices. You may need to mount your devpts or devfs filesystem on
821 /dev/pts for this to work.
823 Most people should answer Y.
825 config UNIX98PTY_ONLY
826 bool "Support only Unix 98 PTYs"
828 depends on UCLIBC_HAS_PTY
830 If you want to support only Unix 98 PTYs enable this. Some older
831 applications may need this disabled and will thus use legacy BSD
832 style PTY handling which is more complex and also bigger than
833 Unix 98 PTY handling.
835 For most current programs, you can generally answer Y.
838 config UCLIBC_HAS_GETPT
839 bool "Support getpt() (glibc-compat)"
840 depends on UCLIBC_HAS_PTY
842 Some packages may need getpt().
843 All of those are non-standard and can be considered
844 GNU/libc compatibility.
845 Either use posix_openpt() or just open /dev/ptmx yourself.
847 If unsure, just say N.
851 # Have to use __libc_ptyname{1,2}[] and related bloat
852 config UCLIBC_HAS_GETPT
856 config UCLIBC_HAS_LIBUTIL
857 bool "Provide libutil library and functions"
858 depends on UCLIBC_HAS_PTY
860 Provide a libutil library.
861 This non-standard conforming library provides the following
864 forkpty(): combines openpty(), fork(2), and login_tty() to
865 create a new process operating in a pseudo-terminal.
866 login(): write utmp and wtmp entries
867 login_tty(): prepares for a login on the tty fd by creating a
868 new session, making fd the controlling terminal for
869 the calling process, setting fd to be the standard
870 input, output, and error streams of the current
871 process, and closing fd.
872 logout(): write utmp and wtmp entries
873 logwtmp(): constructs a utmp structure and calls updwtmp() to
874 append the structure to the utmp file.
875 openpty(): finds an available pseudo-terminal and returns
876 file descriptors for the master and slave
878 This library adds about 3k-4k to your system.
880 config UCLIBC_HAS_TM_EXTENSIONS
881 bool "Support 'struct tm' timezone extension fields"
884 Enabling this option adds fields to 'struct tm' in time.h for
885 tracking the number of seconds east of UTC, and an abbreviation for
886 the current timezone. These fields are not specified by the SuSv3
887 standard, but they are commonly used in both GNU and BSD application
890 To strictly follow the SuSv3 standard, leave this disabled.
891 Most people will probably want to answer Y.
893 config UCLIBC_HAS_TZ_CACHING
894 bool "Enable caching of the last valid timezone 'TZ' string"
897 Answer Y to enable caching of the last valid 'TZ' string describing
898 the timezone setting. This allows a quick string compare to avoid
899 repeated parsing of unchanged 'TZ' strings when tzset() is called.
901 Most people will answer Y.
903 config UCLIBC_HAS_TZ_FILE
904 bool "Enable '/etc/TZ' file support to set a default timezone (uClibc-specific)"
907 Answer Y to enable the setting of a default timezone for uClibc.
909 Ordinarily, uClibc gets the timezone information exclusively from the
910 'TZ' environment variable. In particular, there is no support for
911 the zoneinfo directory tree or the /etc/timezone file used by glibc.
913 With this option enabled, uClibc will use the value stored in the
914 file '/etc/TZ' (default path) to obtain timezone information if the
915 'TZ' environment variable is missing or has an invalid value. The
916 file consists of a single line (newline required) of text describing
917 the timezone in the format specified for the TZ environment variable.
919 Doing 'echo CST6CDT > /etc/TZ' is enough to create a valid file.
921 http://www.opengroup.org/onlinepubs/007904975/basedefs/xbd_chap08.html
922 for details on valid settings of 'TZ'.
924 Most people will answer Y.
926 config UCLIBC_HAS_TZ_FILE_READ_MANY
927 bool "Repeatedly read the '/etc/TZ' file"
928 depends on UCLIBC_HAS_TZ_FILE
931 Answer Y to enable repeated reading of the '/etc/TZ' file even after
932 a valid value has been read. This incurs the overhead of an
933 open/read/close for each tzset() call (explicit or implied). However,
934 setting this will allow applications to update their timezone
935 information if the contents of the file change.
937 Most people will answer Y.
939 config UCLIBC_TZ_FILE_PATH
940 string "Path to the 'TZ' file for setting the global timezone"
941 depends on UCLIBC_HAS_TZ_FILE
944 This is the path to the 'TZ' file.
946 Most people will use the default of '/etc/TZ'.
948 config UCLIBC_FALLBACK_TO_ETC_LOCALTIME
949 bool "Use /etc/localtime as a fallback"
950 depends on UCLIBC_HAS_TZ_FILE
953 Answer Y to try to use /etc/localtime file.
954 On glibc systems this file (if it is in TZif2 format)
955 contains timezone string at the end.
957 Most people will answer Y.
961 menu "Advanced Library Settings"
963 config UCLIBC_PWD_BUFFER_SIZE
964 int "Buffer size for getpwnam() and friends"
968 This sets the value of the buffer size for getpwnam() and friends.
969 By default, this is 256. (For reference, glibc uses 1024).
970 The value can be found using sysconf() with the _SC_GETPW_R_SIZE_MAX
973 config UCLIBC_GRP_BUFFER_SIZE
974 int "Buffer size for getgrnam() and friends"
978 This sets the value of the buffer size for getgrnam() and friends.
979 By default, this is 256. (For reference, glibc uses 1024).
980 The value can be found using sysconf() with the _SC_GETGR_R_SIZE_MAX
983 comment "Support various families of functions"
985 config UCLIBC_LINUX_MODULE_26
986 bool "Linux kernel module functions (2.6)"
989 delete_module, init_module
990 are used in linux for loadable kernel modules.
992 Say N if you do not use kernel modules.
994 config UCLIBC_LINUX_MODULE_24
995 bool "Linux kernel module functions (<2.6)"
996 depends on !TARGET_bfin && !TARGET_c6x
998 create_module, query_module
999 are used in linux (prior to 2.6) for loadable kernel modules.
1001 Say N if you do not use kernel modules, or you only support
1004 config UCLIBC_LINUX_SPECIFIC
1005 bool "Linux specific functions"
1008 accept4(), bdflush(),
1009 capget(), capset(), eventfd(), fstatfs(),
1010 inotify_*(), ioperm(), iopl(),
1011 madvise(), modify_ldt(), pipe2(), personality(),
1012 prctl()/arch_prctl(), pivot_root(), modify_ldt(),
1013 ppoll(), readahead(), reboot(), remap_file_pages(),
1014 sched_getaffinity(), sched_setaffinity(), sendfile(),
1015 setfsgid(), setfsuid(), setresgid(), setresuid(),
1016 splice(), vmsplice(), tee(), signalfd(), swapoff(), swapon(),
1017 sync_file_range(), _sysctl(), sysinfo(), timerfd_*(), vhangup(),
1020 config UCLIBC_HAS_GNU_ERROR
1021 bool "Support GNU extensions for error-reporting"
1024 Support for the GNU-specific error(), error_at_line(),
1025 void (* error_print_progname)(), error_message_count
1026 functions and variables. Some GNU packages
1027 utilize these for extra useful output, but in general
1030 If unsure, just answer N.
1032 config UCLIBC_BSD_SPECIFIC
1033 bool "BSD specific functions"
1036 mincore(), getdomainname(), setdomainname()
1040 config UCLIBC_HAS_BSD_ERR
1041 bool "BSD err functions"
1044 These functions are non-standard BSD extensions.
1045 err(), errx(), warn(), warnx(), verr(), verrx(), vwarn(), vwarnx()
1049 config UCLIBC_HAS_OBSOLETE_BSD_SIGNAL
1050 bool "BSD obsolete signal functions"
1052 These functions are provided as a compatibility interface for
1053 programs that make use of the historical System V signal API.
1054 This API is obsolete:
1055 new applications should use the POSIX signal API (sigaction(2),
1056 sigprocmask(2), etc.).
1059 sigset(), sighold(), sigrelse(), sigignore()
1063 config UCLIBC_HAS_OBSOLETE_SYSV_SIGNAL
1064 bool "SYSV obsolete signal functions"
1066 Use of sysv_signal() should be avoided; use sigaction(2) instead.
1070 config UCLIBC_NTP_LEGACY
1071 bool "ntp_*() aliases"
1073 Provide legacy aliases for ntp functions:
1074 ntp_adjtime(), ntp_gettime()
1076 It is safe to say N here.
1078 config UCLIBC_SV4_DEPRECATED
1079 bool "Enable SVr4 deprecated functions"
1081 These functions are DEPRECATED in System V release 4.
1082 Say N unless you desparately need one of the functions below:
1084 ustat() [use statfs(2) in your code instead]
1086 config UCLIBC_HAS_REALTIME
1087 bool "Realtime-related family of SUSv functions"
1090 These functions are part of the Timers option and need not
1091 be available on all implementations.
1092 Includes AIO, message-queue, scheduler, semaphore functions:
1107 clock_getres(), clock_gettime(), clock_settime()
1109 mlockall(), munlockall()
1121 sched_get_priority_max(), sched_get_priority_min()
1122 sched_getscheduler()
1123 sched_rr_get_interval()
1125 sched_setscheduler()
1132 sem_trywait(), sem_wait()
1135 sigtimedwait(), sigwaitinfo()
1138 timer_getoverrun(), timer_gettime(), timer_settime()
1140 config UCLIBC_HAS_ADVANCED_REALTIME
1141 bool "Advanced realtime-related family of SUSv functions"
1143 depends on UCLIBC_HAS_REALTIME
1145 These functions are part of the Timers option and need not
1146 be available on all implementations.
1148 clock_getcpuclockid()
1157 posix_spawnattr_destroy(), posix_spawnattr_init()
1158 posix_spawnattr_getflags(), posix_spawnattr_setflags()
1159 posix_spawnattr_getpgroup(), posix_spawnattr_setpgroup()
1160 posix_spawnattr_getschedparam(), posix_spawnattr_setschedparam()
1161 posix_spawnattr_getschedpolicy(), posix_spawnattr_setschedpolicy()
1162 posix_spawnattr_getsigdefault(), posix_spawnattr_setsigdefault()
1163 posix_spawnattr_getsigmask(), posix_spawnattr_setsigmask()
1164 posix_spawn_file_actions_addclose()
1165 posix_spawn_file_actions_adddup2()
1166 posix_spawn_file_actions_addopen()
1167 posix_spawn_file_actions_destroy()
1168 posix_spawn_file_actions_init()
1171 posix_typed_mem_get_info()
1172 pthread_mutex_timedlock()
1175 #config UCLIBC_HAS_TERMIOS
1176 # bool "termios functions"
1179 # Get and set terminal attributes, line control, get and set baud
1181 # termios(), tcgetattr(), tcsetattr(), tcsendbreak(), tcdrain(),
1182 # tcflush(), tcflow(), cfmakeraw(), cfgetospeed(), cfgetispeed(),
1183 # cfsetispeed(), cfsetospeed(), cfsetspeed()
1187 config UCLIBC_HAS_EPOLL
1191 epoll_create(), epoll_ctl(), epoll_wait() functions.
1193 config UCLIBC_HAS_XATTR
1194 bool "Extended Attributes"
1197 Extended Attributes support.
1212 Say N unless you need support for extended attributes and the
1213 filesystems do actually support them.
1215 config UCLIBC_HAS_PROFILING
1216 bool "Profiling support"
1219 gcc's -finstrument-functions needs these.
1221 Most people can safely answer N.
1223 config UCLIBC_HAS_CRYPT_IMPL
1224 bool "libcrypt support"
1227 libcrypt contains crypt(), setkey() and encrypt()
1229 config UCLIBC_HAS_SHA256_CRYPT_IMPL
1230 bool "libcrypt SHA256 support"
1231 depends on UCLIBC_HAS_CRYPT_IMPL
1233 This adds support for SHA256 password hashing via the crypt() function.
1234 Say N here if you do not need SHA256 crypt support.
1236 config UCLIBC_HAS_SHA512_CRYPT_IMPL
1237 bool "libcrypt SHA512 support"
1238 depends on UCLIBC_HAS_CRYPT_IMPL
1240 This adds support for SHA512 password hashing via the crypt() function.
1241 Say N here if you do not need SHA512 crypt support.
1243 config UCLIBC_HAS_CRYPT_STUB
1244 bool "libcrypt stubs"
1246 depends on !UCLIBC_HAS_CRYPT_IMPL
1248 Standards mandate that crypt(3) provides a stub if it is unavailable.
1249 If you enable this option then stubs for
1250 crypt(), setkey() and encrypt()
1251 will be provided in a small libcrypt.
1253 config UCLIBC_HAS_CRYPT
1255 depends on UCLIBC_HAS_CRYPT_IMPL || UCLIBC_HAS_CRYPT_STUB
1258 menuconfig UCLIBC_HAS_NETWORK_SUPPORT
1259 bool "Networking Support"
1262 Say N here if you do not need network support.
1264 if UCLIBC_HAS_NETWORK_SUPPORT
1265 config UCLIBC_HAS_SOCKET
1266 bool "Socket support"
1269 If you want to include support for sockets then answer Y.
1271 config UCLIBC_HAS_IPV4
1272 bool "IP version 4 support"
1274 select UCLIBC_HAS_SOCKET
1276 If you want to include support for the Internet Protocol
1277 (IP version 4) then answer Y.
1279 Most people will say Y.
1281 config UCLIBC_HAS_IPV6
1282 bool "IP version 6 support"
1283 select UCLIBC_HAS_SOCKET
1285 If you want to include support for the next version of the Internet
1286 Protocol (IP version 6) then answer Y.
1288 Most people should answer N.
1290 config UCLIBC_HAS_RPC
1291 bool "Remote Procedure Call (RPC) support"
1292 # RPC+socket-ipvX doesn't currently work.
1293 depends on UCLIBC_HAS_IPV4 || UCLIBC_HAS_IPV6
1295 If you want to include RPC support, enable this. RPC is rarely used
1296 for anything except for the NFS filesystem. Unless you plan to use
1297 NFS, you can probably leave this set to N and save some space.
1299 If you need to use NFS then you should answer Y.
1301 config UCLIBC_HAS_FULL_RPC
1302 bool "Full RPC support"
1303 depends on UCLIBC_HAS_RPC
1304 default y if !HAVE_SHARED
1306 Normally we enable just enough RPC support for things like rshd and
1307 nfs mounts to work. If you find you need the rest of the RPC stuff,
1308 then enable this option. Most people can safely answer N.
1310 config UCLIBC_HAS_REENTRANT_RPC
1311 bool "Reentrant RPC support"
1312 depends on UCLIBC_HAS_RPC
1313 default y if !HAVE_SHARED
1315 Most packages utilize the normal (non-reentrant) RPC functions, but
1316 some (like exportfs from nfs-utils) need these reentrant versions.
1318 Most people can safely answer N.
1320 config UCLIBC_USE_NETLINK
1321 bool "Use netlink to query interfaces"
1322 depends on UCLIBC_HAS_SOCKET
1324 In newer versions of Linux (2.4.17+), support was added for querying
1325 network device information via netlink rather than the old style
1326 ioctl's. Most of the time, the older ioctl style is sufficient (and
1327 it is smaller than netlink), but if you find that not all of your
1328 devices are being returned by the if_nameindex() function, you will
1329 have to use the netlink implementation.
1331 Most people can safely answer N.
1333 config UCLIBC_SUPPORT_AI_ADDRCONFIG
1334 bool "Support the AI_ADDRCONFIG flag"
1335 depends on UCLIBC_USE_NETLINK
1337 The implementation of AI_ADDRCONFIG is aligned with the glibc
1338 implementation using netlink to query interfaces to find both
1339 ipv4 and ipv6 support. This is only needed if an application uses
1340 the AI_ADDRCONFIG flag.
1342 Most people can safely answer N.
1344 config UCLIBC_HAS_BSD_RES_CLOSE
1345 bool "Support res_close() (bsd-compat)"
1347 Answer Y if you desperately want to support BSD compatibility in
1350 Most people will say N.
1352 config UCLIBC_HAS_COMPAT_RES_STATE
1353 bool "Use compatible but bloated _res"
1356 Answer Y if you build network utilities and they muck with resolver
1357 internals a lot (_res global structure). uclibc does not use most
1358 of _res.XXX fields, and with this option OFF they won't even exist.
1359 Which will make e.g. dig build fail.
1360 Answering N saves around 400 bytes in bss.
1362 config UCLIBC_HAS_EXTRA_COMPAT_RES_STATE
1363 bool "Use extra compatible but extra bloated _res"
1365 Answer Y if selecting UCLIBC_HAS_COMPAT_RES_STATE is not enough.
1366 As far as I can say, this should never be needed.
1368 config UCLIBC_HAS_RESOLVER_SUPPORT
1369 bool "DNS resolver functions"
1370 select UCLIBC_HAS_COMPAT_RES_STATE
1371 depends on UCLIBC_HAS_IPV4 || UCLIBC_HAS_IPV6
1373 Provide implementations for DNS resolver functions.
1374 In particular, the following functions will be added to the
1377 ns_skiprr, ns_initparse, ns_parserr, ns_msg_getflag,
1378 res_mkquery, res_init, res_ninit, res_close, res_nclose
1379 res_query, res_search, res_querydomain,
1381 ns_name_uncompress, ns_name_ntop, ns_name_pton, ns_name_unpack,
1382 ns_name_pack, ns_name_compress, ns_name_skip, dn_skipname,
1383 ns_get16, ns_get32, ns_put16, ns_put32
1385 config UCLIBC_HAS_LIBRESOLV_STUB
1386 bool "Provide libresolv stub"
1388 Provide a dummy resolv library.
1390 config UCLIBC_HAS_LIBNSL_STUB
1391 bool "Provide libnsl stub"
1393 Provide a dummy nsl library.
1398 menu "String and Stdio Support"
1400 config UCLIBC_HAS_STRING_GENERIC_OPT
1401 bool "Use faster (but larger) generic string functions"
1404 Answer Y to use the (tweaked) glibc generic string functions.
1406 In general, they are faster (but 3-5K larger) than the base
1407 uClibc string functions which are optimized solely for size.
1409 Many people will answer Y.
1411 config UCLIBC_HAS_STRING_ARCH_OPT
1412 bool "Use arch-specific assembly string functions (where available)"
1415 Answer Y to use any archtecture-specific assembly language string
1416 functions available for this target plaform.
1418 Note that assembly implementations are not available for all string
1419 functions, so some generic (written in C) string functions may
1422 These are small and fast, the only reason _not_ to say Y here is
1423 for debugging purposes.
1425 config UCLIBC_HAS_CTYPE_TABLES
1426 bool "Use Table Versions Of 'ctype.h' Functions."
1429 Answer Y to use table versions of the 'ctype.h' functions.
1430 While the non-table versions are often smaller when building
1431 statically linked apps, they work only in stub locale mode.
1433 Most people will answer Y.
1435 config UCLIBC_HAS_CTYPE_SIGNED
1436 bool "Support Signed Characters In 'ctype.h' Functions."
1437 depends on UCLIBC_HAS_CTYPE_TABLES
1440 Answer Y to enable support for passing signed char values to
1441 the 'ctype.h' functions. ANSI/ISO C99 and SUSv3 specify that
1442 these functions are only defined for unsigned char values and
1443 EOF. However, glibc allows negative signed char values as well
1444 in order to support 'broken old programs'.
1446 Most people will answer Y.
1449 prompt "ctype argument checking"
1450 depends on UCLIBC_HAS_CTYPE_TABLES
1451 default UCLIBC_HAS_CTYPE_UNSAFE
1453 Please select the invalid arg behavior you want for the 'ctype'
1456 The 'ctype' functions are now implemented using table lookups, with
1457 the arg being the index. This can result in incorrect memory accesses
1458 or even segfaults for args outside of the allowed range.
1460 NOTE: This only affects the 'ctype' _functions_. It does not affect
1461 the macro implementations.
1463 config UCLIBC_HAS_CTYPE_UNSAFE
1464 bool "Do not check -- unsafe"
1466 config UCLIBC_HAS_CTYPE_CHECKED
1467 bool "Detect and handle appropriately"
1469 config UCLIBC_HAS_CTYPE_ENFORCED
1470 bool "Issue a diagnostic and abort()"
1475 config UCLIBC_HAS_WCHAR
1476 bool "Wide Character Support"
1478 Answer Y to enable wide character support. This will make uClibc
1479 much larger. It is also currently required for locale support.
1481 Most people will answer N.
1483 config UCLIBC_HAS_LOCALE
1484 bool "Locale Support"
1485 select UCLIBC_HAS_WCHAR
1486 select UCLIBC_HAS_CTYPE_TABLES
1488 uClibc now has full ANSI/ISO C99 locale support (except for
1489 wcsftime() and collating items in regex). Be aware that enabling
1490 this option will make uClibc much larger.
1492 Enabling UCLIBC_HAS_LOCALE with the default set of supported locales
1493 (169 UTF-8 locales, and 144 locales for other codesets) will enlarge
1494 uClibc by around 300k. You can reduce this size by building your own
1495 custom set of locate data (see extra/locale/LOCALES for details).
1497 uClibc's locale support is still under development. For example,
1498 codesets using shift states are not currently supported. Support is
1499 planned in the next iteration of locale support.
1501 Answer Y to enable locale support. Most people will answer N.
1505 prompt "Locale data"
1506 depends on UCLIBC_HAS_LOCALE
1507 default UCLIBC_BUILD_ALL_LOCALE
1509 config UCLIBC_BUILD_ALL_LOCALE
1511 depends on UCLIBC_HAS_LOCALE
1513 This builds all the locales that are available on your
1516 config UCLIBC_BUILD_MINIMAL_LOCALE
1517 bool "Only selected locales"
1518 depends on UCLIBC_HAS_LOCALE
1520 If you do not need all locales that are available on your
1521 host-box, then set this to 'Y'.
1523 config UCLIBC_PREGENERATED_LOCALE_DATA
1524 bool "Use Pre-generated Locale Data"
1525 depends on UCLIBC_HAS_LOCALE && !TARGET_metag
1527 Use pre-built locale data.
1529 Note that these pregenerated locales are sensitive to your
1530 target architecture (endianess, bitcount).
1532 Saying N here is highly recommended.
1536 config UCLIBC_BUILD_MINIMAL_LOCALES
1537 string "locales to use"
1538 depends on UCLIBC_BUILD_MINIMAL_LOCALE
1541 Space separated list of locales to use.
1548 config UCLIBC_DOWNLOAD_PREGENERATED_LOCALE_DATA
1549 bool "Automagically Download the Pre-generated Locale Data (if necessary)"
1550 depends on UCLIBC_PREGENERATED_LOCALE_DATA
1552 If you would like the build process to use 'wget' to automatically
1553 download the pregenerated locale data, enable this option. Otherwise
1554 you will need to obtain the locale data yourself from:
1555 http://www.uclibc.org/downloads/uClibc-locale-*.tgz
1556 and place the uClibc-locale-*.tgz tarball in the extra/locale/
1559 Note that the use of pregenerated locale data is discouraged.
1561 config UCLIBC_HAS_XLOCALE
1562 bool "Extended Locale Support (experimental/incomplete)"
1563 depends on UCLIBC_HAS_LOCALE
1565 Answer Y to enable extended locale support similar to that provided
1566 by glibc. This is primarily intended to support libstd++
1568 However, it also allows thread-specific locale selection via
1571 Most people will answer N.
1573 config UCLIBC_HAS_HEXADECIMAL_FLOATS
1574 bool "Support hexadecimal float notation"
1575 depends on UCLIBC_HAS_CTYPE_TABLES
1576 depends on UCLIBC_HAS_FLOATS
1578 Answer Y to enable support for hexadecimal float notation in the
1579 (wchar and) char string to floating point conversion functions, as
1580 well as support for the %a and %A conversion specifiers in the
1581 *printf() and *scanf() functions.
1583 Most people will answer N.
1585 config UCLIBC_HAS_GLIBC_DIGIT_GROUPING
1586 bool "Support glibc's \"'\" flag for allowing locale-specific digit grouping"
1587 depends on UCLIBC_HAS_LOCALE
1588 depends on UCLIBC_HAS_FLOATS
1590 Answer Y to enable support for glibc's \"'\" flag for allowing
1591 locale-specific digit grouping in base 10 integer conversions and
1592 appropriate floating point conversions in the *printf() and *scanf()
1595 Most people will answer N.
1597 config UCLIBC_HAS_SCANF_LENIENT_DIGIT_GROUPING
1598 bool "Do not require digit grouping when the \"'\" flag is specified"
1599 depends on UCLIBC_HAS_GLIBC_DIGIT_GROUPING
1602 Answer Y to make digit grouping optional when the \"'\" flag is
1604 This is the standard glibc behavior. If the initial string of digits
1605 exceeds the maximum group number, the input will be treated as a
1606 normal non-grouped number.
1608 Most people will answer N.
1610 config UCLIBC_HAS_GLIBC_CUSTOM_PRINTF
1611 bool "Support glibc's register_printf_function() (glibc-compat)"
1612 depends on !USE_OLD_VFPRINTF
1614 Answer Y to support glibc's register_printf_function() to allow an
1615 application to add its own printf conversion specifiers.
1616 parse_printf_format() is also enabled.
1618 NOTE: Limits the number or registered specifiers to 10.
1619 NOTE: Requires new conversion specifiers to be ASCII
1620 characters (0-0x7f). This is to avoid problems with processing
1621 format strings in locales with different multibyte conversions.
1623 Most people will answer N.
1625 config USE_OLD_VFPRINTF
1626 bool "Use the old vfprintf implementation"
1627 depends on !UCLIBC_HAS_WCHAR
1629 Set to true to use the old vfprintf instead of the new. This is
1630 roughly C89 compliant with some extensions, and is much smaller.
1631 However, it does not support wide chars, positional args, or glibc
1632 custom printf specifiers.
1634 Most people will answer N.
1636 config UCLIBC_PRINTF_SCANF_POSITIONAL_ARGS
1637 int "Maximum number of positional args. Either 0 or >= 9."
1638 depends on !USE_OLD_VFPRINTF
1641 Set the maximum number of positional args supported by the
1642 printf/scanf functions. The Single Unix Specification Version 3
1643 requires a minimum value of 9. Setting this to a value lower than
1644 9 will disable positional arg support and cause the NL_ARGMAX macro
1645 in limits.h to be #undef'd.
1647 WARNING! The workspace to support positional args is currently
1648 allocated on the stack. You probably don't want to set
1649 this to too high a value.
1651 Most people will answer 9.
1654 prompt "Stdio buffer size"
1655 default UCLIBC_HAS_STDIO_BUFSIZ_4096
1657 Please select a value for BUFSIZ. This will be used by the
1658 stdio subsystem as the default buffer size for a file, and
1659 affects fopen(), setvbuf(), etc.
1661 NOTE: Setting this to 'none' will disable buffering completely.
1662 However, BUFSIZ will still be defined in stdio.h as 256 because
1663 many applications use this value.
1665 config UCLIBC_HAS_STDIO_BUFSIZ_NONE
1666 bool "none (WARNING - BUFSIZ will be 256 in stdio.h)"
1667 depends on !UCLIBC_HAS_WCHAR
1669 config UCLIBC_HAS_STDIO_BUFSIZ_256
1670 bool "256 (minimum ANSI/ISO C99 value)"
1672 config UCLIBC_HAS_STDIO_BUFSIZ_512
1675 config UCLIBC_HAS_STDIO_BUFSIZ_1024
1678 config UCLIBC_HAS_STDIO_BUFSIZ_2048
1681 config UCLIBC_HAS_STDIO_BUFSIZ_4096
1684 config UCLIBC_HAS_STDIO_BUFSIZ_8192
1687 # If you add more choices, you will need to update uClibc_stdio.h.
1692 prompt "Stdio builtin buffer size (uClibc-specific)"
1693 depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
1694 default UCLIBC_HAS_STDIO_BUILTIN_BUFFER_NONE
1696 When a FILE is created with fopen(), an attempt is made to allocate
1697 a BUFSIZ buffer for it. If the allocation fails, fopen() will still
1698 succeed but the FILE will be unbuffered.
1700 This option adds a small amount of space to each FILE to act as an
1701 emergency buffer in the event of a buffer allocation failure.
1703 Most people will answer None.
1705 config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_NONE
1708 config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_4
1711 config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_8
1714 # If you add more choices, you will need to update uClibc_stdio.h.
1718 config UCLIBC_HAS_STDIO_SHUTDOWN_ON_ABORT
1719 bool "Attempt to shutdown stdio subsystem when abort() is called."
1721 ANSI/ISO C99 requires abort() to be asyn-signal-safe. So there was
1722 a behavioral change made in SUSv3. Previously, abort() was required
1723 to have the affect of fclose() on all open streams. The wording has
1724 been changed to "may" from "shall".
1726 Most people will answer N.
1728 config UCLIBC_HAS_STDIO_GETC_MACRO
1729 bool "Provide a macro version of getc()"
1730 depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
1733 Provide a macro version of getc().
1735 Most people will answer Y.
1737 config UCLIBC_HAS_STDIO_PUTC_MACRO
1738 bool "Provide a macro version of putc()"
1739 depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
1742 Provide a macro version of putc().
1744 Most people will answer Y.
1746 config UCLIBC_HAS_STDIO_AUTO_RW_TRANSITION
1747 bool "Support auto-r/w transition"
1750 Answer Y to enable the stdio subsystem to automaticly transition
1751 between reading and writing. This relaxes the ANSI/ISO C99
1754 When a file is opened with update mode ('+' as the second or third
1755 character in the list of mode argument values), both input and output
1756 may be performed on the associated stream. However, output shall not
1757 be directly followed by input without an intervening call to the
1758 fflush function or to a file positioning function (fseek, fsetpos,
1759 or rewind), and input shall not be directly followed by output without
1760 an intervening call to a file positioning function, unless the input
1761 operation encounters endÂofÂfile.
1763 Most people will answer Y.
1765 config UCLIBC_HAS_FOPEN_LARGEFILE_MODE
1766 bool "Support an fopen() 'F' flag for large file mode (uClibc-specific)"
1767 depends on UCLIBC_HAS_LFS
1769 Answer Y to enable a uClibc-specific extension to allow passing an
1770 additional 'F' flag in the mode string for fopen() to specify that
1771 the file should be open()ed with the O_LARGEFILE flag set.
1773 Most people will answer N.
1775 config UCLIBC_HAS_FOPEN_EXCLUSIVE_MODE
1776 bool "Support an fopen() 'x' flag for exclusive mode (glibc-compat)"
1778 Answer Y to support a glibc extension to allow passing
1779 additional 'x' flag in the mode string for fopen() to specify that
1780 the file should be open()ed with the O_EXCL flag set.
1782 Most people will answer N.
1784 config UCLIBC_HAS_FOPEN_CLOSEEXEC_MODE
1785 bool "Support an fopen() 'e' flag for close-on-exec mode (glibc-compat)"
1787 Answer Y to support a glibc extension to allow passing
1788 additional 'e' flag in the mode string for fopen() to specify that
1789 the file should be open()ed with the O_CLOEXEC flag set.
1791 Most people will answer N.
1793 config UCLIBC_HAS_GLIBC_CUSTOM_STREAMS
1794 bool "Support fmemopen(), open_memstream(), and fopencookie() (glibc-compat)"
1796 Answer Y to support the glibc 'custom stream' extension functions
1797 fmemopen(), open_memstream(), and fopencookie().
1799 NOTE: There are some minor differences regarding seeking behavior.
1801 Most people will answer N.
1803 config UCLIBC_HAS_PRINTF_M_SPEC
1804 bool "Support the '%m' specifier in printf format strings (glibc-compat)"
1806 Answer Y to support a glibc extension to interpret '%m' in printf
1807 format strings as an instruction to output the error message string
1808 (as generated by strerror) corresponding to the current value of
1811 Most people will answer N.
1813 config UCLIBC_HAS_ERRNO_MESSAGES
1814 bool "Include the errno message text in the library"
1817 Answer Y if you want to include the errno message text in the
1818 library. This adds about 3K to the library, but enables strerror()
1819 to generate text other than 'Unknown error <number>'.
1821 Most people will answer Y.
1823 config UCLIBC_HAS_SYS_ERRLIST
1824 bool "Support sys_errlist[] (obsolete-compat)"
1825 depends on UCLIBC_HAS_ERRNO_MESSAGES
1827 Answer Y if you want to support the obsolete sys_errlist[].
1828 This adds about 0.5k to the library, except for the mips
1829 arch where it adds over 4K.
1831 WARNING! In the future, support for sys_errlist[] may be unavailable
1832 in at least some configurations. In fact, it may be removed
1835 Most people will answer N.
1837 Application writers: use the strerror(3) function.
1839 config UCLIBC_HAS_SIGNUM_MESSAGES
1840 bool "Include the signum message text in the library"
1843 Answer Y if you want to include the signum message text in the
1844 library. This adds about 0.5K to the library, but enables strsignal()
1845 to generate text other than 'Unknown signal <number>'.
1847 Most people will answer Y.
1849 config UCLIBC_HAS_SYS_SIGLIST
1850 bool "Support sys_siglist[] (bsd-compat)"
1851 depends on UCLIBC_HAS_SIGNUM_MESSAGES
1853 Answer Y if you want to support sys_siglist[].
1855 WARNING! In the future, support for sys_siglist[] may be unavailable
1856 in at least some configurations. In fact, it may be removed
1859 Most people will answer N.
1861 config UCLIBC_HAS_GETTEXT_AWARENESS
1862 bool "Include gettext awareness"
1863 depends on UCLIBC_HAS_LOCALE && UCLIBC_MJN3_ONLY
1865 NOTE!!! Not yet integrated with strerror and strsignal. NOTE!!!
1867 Answer Y if you want to include weak stub gettext support and
1868 make the *strerror*() and strsignal() functions gettext-aware.
1870 Currently, to get functional gettext functionality you will need
1873 Most people will answer N.
1875 config UCLIBC_HAS_GNU_GETOPT
1876 bool "Support gnu getopt"
1879 Answer Y if you want to include full gnu getopt() instead of a
1880 (much smaller) SUSv3 compatible getopt().
1882 Most people will answer Y.
1884 config UCLIBC_HAS_STDIO_FUTEXES
1885 bool "Use futexes for multithreaded I/O locking"
1886 depends on UCLIBC_HAS_THREADS_NATIVE
1888 If you want to compile uClibc to use futexes for low-level
1889 I/O locking, answer Y. Otherwise, answer N.
1891 config UCLIBC_HAS_GETOPT_LONG
1892 bool "Support getopt_long/getopt_long_only"
1893 depends on !UCLIBC_HAS_GNU_GETOPT
1896 Answer Y if you want to include getopt_long[_only() used by many
1899 Most people will answer Y.
1901 config UCLIBC_HAS_GNU_GETSUBOPT
1902 bool "Support glibc getsubopt"
1905 Answer Y if you want to include glibc getsubopt() instead of a
1906 smaller SUSv3 compatible getsubopt().
1908 Most people will answer Y.
1914 config UCLIBC_HAS_REGEX
1915 bool "Regular Expression Support"
1918 POSIX regular expression code is really big -- 53k all by itself.
1919 If you don't use regular expressions, turn this off and save space.
1920 Of course, if you only statically link, leave this on, since it will
1921 only be included in your apps if you use regular expressions.
1923 config UCLIBC_HAS_REGEX_OLD
1924 bool "Use the older (stable) regular expression code"
1925 depends on UCLIBC_HAS_REGEX
1928 There are two versions of regex. The older (stable) version has
1929 been in uClibc for quite a long time but hasn't seen too many
1930 updates. It also has some known issues when dealing with uncommon
1931 corner cases and multibyte/unicode strings. However, it is quite
1932 a bit smaller than the newer version.
1934 If the older version has worked for you and you don't need unicode
1935 support, then stick with the old version (and say Y here).
1936 Otherwise, you should use the new version (and say N here).
1938 config UCLIBC_HAS_FNMATCH
1939 bool "fnmatch Support"
1944 config UCLIBC_HAS_FNMATCH_OLD
1945 bool "Use the older (stable) fnmatch code"
1946 depends on UCLIBC_HAS_FNMATCH
1949 There are two versions of fnmatch. The older (stable) version has
1950 been in uClibc for quite a long time but hasn't seen too many
1951 updates. It also has some known issues when dealing with uncommon
1952 corner cases and multibyte/unicode strings. However, it is quite
1953 a bit smaller than the newer version.
1955 If the older version has worked for you and you don't need unicode
1956 support, then stick with the old version (and say Y here).
1957 Otherwise, you should use the new version (and say N here).
1959 config UCLIBC_HAS_WORDEXP
1960 bool "Support the wordexp() interface"
1961 depends on UCLIBC_HAS_GLOB
1963 The SuSv3 wordexp() interface performs word expansions per the Shell
1964 and Utilities volume of IEEE Std 1003.1-2001, Section 2.6. It is
1965 intended for use by applications that want to implement all of the
1966 standard Bourne shell expansions on input data.
1968 This interface is rarely used, and very large. Unless you have a
1969 pressing need for wordexp(), you should probably answer N.
1971 config UCLIBC_HAS_NFTW
1972 bool "Support the nftw() interface"
1974 The SuSv3 nftw() interface is used to recursively descend
1975 directory paths while repeatedly calling a function.
1977 This interface is rarely used, and adds around 4.5k. Unless you have
1978 a pressing need for nftw(), you should probably answer N.
1980 config UCLIBC_HAS_FTW
1981 bool "Support the ftw() interface (SUSv4-obsolete)"
1982 depends on UCLIBC_SUSV4_LEGACY
1984 The SuSv3 ftw() interface is used to recursively descend
1985 directory paths while repeatedly calling a function.
1987 This interface is rarely used, and adds around 4.5k. Unless you have
1988 a pressing need for ftw(), you should probably answer N.
1990 config UCLIBC_HAS_FTS
1991 bool "Support the fts() interface (bsd-compat)"
1993 The fts functions are provided for traversing UNIX file hierarchies.
1995 This interface is currently used by the elfutils and adds
1997 You should port your application to use the POSIX nftw()
2000 Unless you need to build/use elfutils, you should prolly answer N.
2002 config UCLIBC_HAS_GLOB
2003 bool "Support the glob() interface"
2004 depends on UCLIBC_HAS_FNMATCH
2008 The glob interface is somewhat large (weighing in at about 2,5k). It
2009 is used fairly often, but is an option since people wanting to go for
2010 absolute minimum size may wish to omit it.
2012 Most people will answer Y.
2014 config UCLIBC_HAS_GNU_GLOB
2015 bool "Support gnu glob() interface"
2016 depends on UCLIBC_HAS_GLOB
2018 The gnu glob interface is somewhat larger (weighing in at about 4,2k)
2019 than it's SuSv3 counterpart (and is out of date). It is an old copy
2020 from glibc and does not support all the GNU specific options.
2022 Answer Y if you want to include full gnu glob() instead of the smaller
2023 SUSv3 compatible glob().
2025 Most people will answer N.
2027 config UCLIBC_HAS_UTMPX
2028 bool "utmpx based support for tracking login/logouts to/from the system"
2030 Answer y to enable support for accessing user accounting database.
2031 It can be used to track all login/logout to the system.
2033 If unsure, just answer N.
2040 menu "Library Installation Options"
2042 config RUNTIME_PREFIX
2043 string "uClibc runtime library directory"
2044 default "/usr/$(TARGET_ARCH)-linux-uclibc/"
2046 RUNTIME_PREFIX is the directory into which the uClibc runtime
2047 libraries will be installed. The result will look something
2050 lib/ <contains all runtime libraries>
2051 usr/bin/ldd <the ldd utility program>
2052 sbin/ldconfig <the ldconfig utility program>
2053 This value is used by the 'make install' Makefile target. Since this
2054 directory is compiled into the shared library loader, you will need to
2055 recompile uClibc if you change this value...
2057 For a typical target system this should be set to "/", such that
2058 'make install' will install /lib/libuClibc-<VERSION>.so
2061 string "uClibc development environment directory"
2062 default "/usr/$(TARGET_ARCH)-linux-uclibc/usr/"
2064 DEVEL_PREFIX is the directory into which the uClibc development
2065 environment will be installed. The result will look something
2068 lib/ <contains static libs>
2069 include/ <Where all the header files go>
2070 This value is used by the 'make install' Makefile target when
2071 installing a uClibc development environment.
2073 For a typical target system this should be set to "/usr", such that
2074 'make install' will install /usr/include/<header files>.
2077 string "library path component"
2080 Path component where libraries reside.
2082 For a typical target system this should be set to "lib", such that
2083 'make install' will install libraries to "/lib" and "/usr/lib"
2085 DEVEL_PREFIX/MULTILIB_DIR
2086 RUNTIME_PREFIX/MULTILIB_DIR
2088 Other settings may include "lib32" or "lib64".
2090 config HARDWIRED_ABSPATH
2091 bool "Hardwire absolute paths into linker scripts"
2094 This prepends absolute paths to the libraries mentioned in linker
2095 scripts such as libc.so.
2097 This is a build time optimization. It has no impact on dynamic
2098 linking at runtime, which doesn't use linker scripts.
2100 You must disable this to use uClibc with old non-sysroot toolchains,
2101 such as the prebuilt binary cross compilers at:
2102 http://uclibc.org/downloads/binaries
2104 The amount of time saved by this optimization is actually too small to
2105 measure. The linker just had to search the library path to find the
2106 linker script, so the dentries are cache hot if it has to search the
2107 same path again. But it's what glibc does, so we do it too.
2112 menu "Security options"
2114 config UCLIBC_BUILD_PIE
2115 bool "Build utilities as ET_DYN/PIE executables"
2116 depends on HAVE_SHARED
2117 depends on TARGET_arm || TARGET_frv || TARGET_i386 || TARGET_mips || TARGET_powerpc
2118 select FORCE_SHAREABLE_TEXT_SEGMENTS
2120 If you answer Y here, ldd and iconv are built as ET_DYN/PIE
2123 It requires gcc-3.4 and binutils-2.15 (for arm 2.16) or later.
2124 More about ET_DYN/PIE binaries on <http://pax.grsecurity.net/> .
2126 WARNING: This option also enables FORCE_SHAREABLE_TEXT_SEGMENTS, so
2127 all libraries have to be built with -fPIC or -fpic, and all
2128 assembler functions must be written as position independent
2131 config UCLIBC_HAS_ARC4RANDOM
2132 bool "Include the arc4random() function"
2134 Answer Y to support the OpenBSD-like arc4random() function. This
2135 function picks a random number between 0 and N, and will always return
2136 something even if the random driver is dead. If urandom fails then
2137 gettimeofday(2) will be used as the random seed. This function is
2138 designed to be more dependable than invoking /dev/urandom directly.
2139 OpenSSL and OpenNTPD currently support this function.
2141 Most people will answer N.
2143 config ARC4RANDOM_USES_NODEV
2144 bool "Do not use /dev/urandom with arc4random()"
2145 depends on UCLIBC_HAS_ARC4RANDOM
2147 Answer Y to use gettimeofday(2) and getpid(2) exclusively for
2148 arc4random(). This is not a bad idea for a diskless system, but
2149 it uses a lot of syscalls to stir each array element.
2151 Most people will answer N.
2156 config UCLIBC_HAS_SSP
2157 bool "Support for GCC stack smashing protector"
2158 depends on !HAVE_NO_SSP
2160 Add code to support GCC's -fstack-protector[-all] option to uClibc.
2161 This requires GCC 4.1 or newer. GCC does not have to provide libssp,
2162 the needed functions are added to ldso/libc instead.
2164 GCC's stack protector is a reimplementation of IBM's propolice.
2165 See http://www.trl.ibm.com/projects/security/ssp/ and
2166 http://www.linuxfromscratch.org/hints/downloads/files/ssp.txt
2169 Note that NOEXECSTACK on a kernel with address space randomization
2170 is generally sufficient to prevent most buffer overflow exploits
2171 without increasing code size. This option essentially adds debugging
2174 Most people will answer N.
2176 config UCLIBC_HAS_SSP_COMPAT
2177 bool "Support for gcc-3.x propolice smashing stack protector"
2178 depends on UCLIBC_HAS_SSP
2180 Add gcc-3.x propolice smashing stack protector to the library.
2182 This requires a patched version of GCC, supporting the
2183 -fstack-protector[-all] options, with the __guard and
2184 __stack_smash_handler functions removed from libgcc.
2185 These functions are added to ldso/libc instead.
2187 More information at:
2188 <http://www.research.ibm.com/trl/projects/security/ssp/>
2190 Most people will answer N.
2192 config SSP_QUICK_CANARY
2193 bool "Use simple guard values without accessing /dev/urandom"
2194 depends on UCLIBC_HAS_SSP
2196 Use gettimeofday(2) to define the __guard without accessing
2198 WARNING: This makes smashing stack protector vulnerable to timing
2200 Most people will answer N.
2203 prompt "Propolice protection blocking signal"
2204 depends on UCLIBC_HAS_SSP
2206 default PROPOLICE_BLOCK_SEGV
2208 "abort" use SIGABRT to block offending programs.
2209 This is the default implementation.
2211 "segfault" use SIGSEGV to block offending programs.
2212 Use this for debugging.
2214 If unsure, answer "abort".
2216 config PROPOLICE_BLOCK_ABRT
2219 config PROPOLICE_BLOCK_SEGV
2224 config UCLIBC_BUILD_SSP
2225 bool "Build uClibc with -fstack-protector"
2226 depends on UCLIBC_HAS_SSP
2228 Build all uClibc libraries and executables with -fstack-protector,
2229 adding extra stack overflow checking to most uClibc functions.
2231 config UCLIBC_BUILD_RELRO
2232 bool "Build uClibc with linker option -z RELRO"
2233 depends on HAVE_SHARED
2236 Build all libraries and executables with "ld -z relro".
2238 This tells the linker to mark chunks of an executable or shared
2239 library read-only after applying dynamic relocations. (This comes
2240 up when a global const variable is initialized to the address of a
2241 function or the value of another global variable.)
2243 This is a fairly obscure option the ld man page doesn't even bother
2244 to document properly. It's a security paranoia issue that's more
2245 likely to consume memory (by allocating an extra page) rather than
2248 This is explained in more depth at
2249 http://www.airs.com/blog/archives/189
2251 Nobody is likely to care whether you say Y or N here.
2253 config UCLIBC_BUILD_NOW
2254 bool "Build uClibc with linker option -z NOW"
2255 depends on HAVE_SHARED
2257 Build all libraries and executables with "ld -z now".
2259 This tells the linker to resolve all symbols when the library is
2260 first loaded, rather than when each function is first called. This
2261 increases start-up latency by a few microseconds and may do
2262 unnecessary work (resolving symbols that are never used), but the
2263 realtime people like it for making microbenchmark timings slightly
2264 more predictable and in some cases it can be slightly faster due to
2265 CPU cache behavior (not having to fault the linker back in to do
2266 lazy symbol resolution).
2268 Most people can't tell the difference between selecting Y or N here.
2270 config UCLIBC_BUILD_NOEXECSTACK
2271 bool "Build uClibc with noexecstack marking"
2274 Mark all assembler files as noexecstack, which will mark uClibc
2275 as not requiring an executable stack. (This doesn't prevent other
2276 files you link against from claiming to need an executable stack, it
2277 just won't cause uClibc to request it unnecessarily.)
2279 This is a security thing to make buffer overflows harder to exploit.
2280 By itself, it's kind of useless, as Linus Torvalds explained in 1998:
2281 http://old.lwn.net/1998/0806/a/linus-noexec.html
2283 It only actually provides any security when combined with address
2284 space randomization, explained here: http://lwn.net/Articles/121845/
2286 Address space randomization is on by default in current linux
2287 kernels (although it can be disabled using the option
2290 You should probably say Y.
2294 menu "Development/debugging options"
2296 config CROSS_COMPILER_PREFIX
2297 string "Cross-compiling toolchain prefix"
2300 The prefix used to execute your cross-compiling toolchain. For
2301 example, if you run 'arm-linux-uclibc-gcc' to compile something,
2302 then enter 'arm-linux-uclibc-' here.
2304 config UCLIBC_EXTRA_CFLAGS
2305 string "Extra CFLAGS"
2308 Add any additional CFLAGS to be used to build uClibc.
2311 bool "Enable debugging symbols"
2312 select EXTRA_WARNINGS
2314 Say Y here if you wish to compile uClibc with debugging symbols.
2315 This will allow you to use a debugger to examine uClibc internals
2316 while applications are running. This increases the size of the
2317 library considerably and should only be used when doing development.
2318 If you are doing development and want to debug uClibc, answer Y.
2320 Otherwise, answer N.
2323 bool "Build pthread with debugging output"
2324 depends on UCLIBC_HAS_THREADS && LINUXTHREADS_OLD
2326 Enable debug output in libpthread. This is only useful when doing
2327 development in libpthread itself.
2329 Otherwise, answer N.
2332 bool "Strip libraries and executables"
2336 Say Y here if you do wish to strip all uClibc libraries and
2337 executables. No stripping increases the size of the binaries
2338 considerably, but makes it possible to debug uClibc libraries.
2339 Most people will answer Y.
2342 bool "Build with run-time assertion testing"
2344 Say Y here to include runtime assertion tests.
2345 This enables runtime assertion testing in some code, which can
2346 increase the size of the library and incur runtime overhead.
2347 If you say N, then this testing will be disabled.
2349 config SUPPORT_LD_DEBUG
2350 bool "Build the shared library loader with debugging support"
2351 depends on HAVE_SHARED
2353 Answer Y here to enable all the extra code needed to debug the uClibc
2354 native shared library loader. The level of debugging noise that is
2355 generated depends on the LD_DEBUG environment variable... Just set
2356 LD_DEBUG to something like: 'LD_DEBUG=token1,token2,.. prog' to
2357 debug your application. Diagnostic messages will then be printed to
2360 For now these debugging tokens are available:
2361 detail provide more information for some options
2362 move display copy processing
2363 symbols display symbol table processing
2364 reloc display relocation processing; detail shows the
2366 nofixups never fixes up jump relocations
2367 bindings displays the resolve processing (function calls);
2368 detail shows the relocation patch
2369 all Enable everything!
2371 The additional environment variable:
2372 LD_DEBUG_OUTPUT=file
2373 redirects the diagnostics to an output file created using
2374 the specified name and the process id as a suffix.
2376 An excellent start is simply:
2377 $ LD_DEBUG=binding,move,symbols,reloc,detail ./appname
2378 or to log everything to a file named 'logfile', try this
2379 $ LD_DEBUG=all LD_DEBUG_OUTPUT=logfile ./appname
2381 If you are doing development and want to debug uClibc's shared library
2382 loader, answer Y. Mere mortals answer N.
2384 config SUPPORT_LD_DEBUG_EARLY
2385 bool "Build the shared library loader with early debugging support"
2386 depends on HAVE_SHARED
2388 Answer Y here to if you find the uClibc shared library loader is
2389 crashing or otherwise not working very early on. This is typical
2390 only when starting a new port when you haven't figured out how to
2391 properly get the values for argc, argv, environ, etc. This method
2392 allows a degree of visibility into the very early shared library
2393 loader initialization process. If you are doing development and want
2394 to debug the uClibc shared library loader early initialization,
2395 answer Y. Mere mortals answer N.
2397 config UCLIBC_MALLOC_DEBUGGING
2398 bool "Build malloc with debugging support"
2399 depends on MALLOC || MALLOC_STANDARD
2402 Answer Y here to compile extra debugging support code into malloc.
2403 Malloc debugging output may then be enabled at runtime using the
2404 MALLOC_DEBUG environment variable.
2406 The value of MALLOC_DEBUG should be an integer, which is interpreted
2407 as a bitmask with the following bits:
2408 1 - do extra consistency checking
2409 2 - output messages for malloc/free calls and OS
2411 4 - output messages for the `MMB' layer
2412 8 - output messages for internal malloc heap manipulation
2415 Because this increases the size of malloc appreciably (due to strings
2416 etc), you should say N unless you need to debug a malloc problem.
2418 config UCLIBC_HAS_BACKTRACE
2419 bool "Add support for application self-debugging"
2420 depends on HAVE_SHARED
2422 Answer Y here to compile support for application self-debugging, by adding
2423 a new shared object "libubacktrace.so" that provides the following new
2425 backtrace, backtrace_symbols, backtrace_symbols_fd
2427 The backtrace functionality is currently supported on SH platform, and it
2428 based on dwarf2 informations to properly work, so any application that
2429 want to use backtrace needs to be built with -fexceptions flag.
2431 The symbol names may be unavailable without the use of special linker
2432 options. For systems using the GNU linker, it is necessary to use the
2433 -rdynamic linker option too. Note that names of "static" functions are not
2434 exposed, and won't be available in the backtrace.
2437 string "Compiler Warnings"
2440 Set this to the set of compiler warnings you wish to see while compiling.
2442 config EXTRA_WARNINGS
2443 bool "Enable extra annoying warnings"
2445 If you wish to build with extra warnings enabled, say Y here.
2448 bool "Compile all sources at once into an object"
2450 Set this to compile all sources at once into an object (IMA).
2451 This mode of compilation uses alot of memory but may produce
2454 Note that you need a very recent GCC for this to work, like
2455 gcc >= 4.3 plus eventually some patches.
2457 If unsure, keep the default of N.
2459 config UCLIBC_MJN3_ONLY
2460 bool "Manuel's hidden warnings"
2462 Answer Y here to see all Manuel's personal notes, warnings, and todos.
2464 Most people will answer N.
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