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_arc if DESIRED_TARGET_ARCH = "arc"
20 default TARGET_arm if DESIRED_TARGET_ARCH = "arm"
21 default TARGET_avr32 if DESIRED_TARGET_ARCH = "avr32"
22 default TARGET_bfin if DESIRED_TARGET_ARCH = "bfin"
23 default TARGET_cris if DESIRED_TARGET_ARCH = "cris"
24 default TARGET_e1 if DESIRED_TARGET_ARCH = "e1"
25 default TARGET_frv if DESIRED_TARGET_ARCH = "frv"
26 default TARGET_h8300 if DESIRED_TARGET_ARCH = "h8300"
27 default TARGET_hppa if DESIRED_TARGET_ARCH = "hppa"
28 default TARGET_i386 if DESIRED_TARGET_ARCH = "i386"
29 default TARGET_i960 if DESIRED_TARGET_ARCH = "i960"
30 default TARGET_ia64 if DESIRED_TARGET_ARCH = "ia64"
31 default TARGET_m68k if DESIRED_TARGET_ARCH = "m68k"
32 default TARGET_metag if DESIRED_TARGET_ARCH = "metag"
33 default TARGET_microblaze if DESIRED_TARGET_ARCH = "microblaze"
34 default TARGET_mips if DESIRED_TARGET_ARCH = "mips"
35 default TARGET_nios if DESIRED_TARGET_ARCH = "nios"
36 default TARGET_nios2 if DESIRED_TARGET_ARCH = "nios2"
37 default TARGET_powerpc if DESIRED_TARGET_ARCH = "powerpc"
38 default TARGET_sh if DESIRED_TARGET_ARCH = "sh"
39 default TARGET_sh64 if DESIRED_TARGET_ARCH = "sh64"
40 default TARGET_sparc if DESIRED_TARGET_ARCH = "sparc"
41 default TARGET_v850 if DESIRED_TARGET_ARCH = "v850"
42 default TARGET_vax if DESIRED_TARGET_ARCH = "vax"
43 default TARGET_x86_64 if DESIRED_TARGET_ARCH = "x86_64"
44 default TARGET_xtensa if DESIRED_TARGET_ARCH = "xtensa"
46 The architecture of your target.
96 config TARGET_microblaze
108 config TARGET_powerpc
135 menu "Target Architecture Features and Options"
138 source "extra/Configs/Config.alpha"
142 source "extra/Configs/Config.arm"
146 source "extra/Configs/Config.avr32"
150 source "extra/Configs/Config.bfin"
154 source "extra/Configs/Config.cris"
158 source "extra/Configs/Config.e1"
162 source "extra/Configs/Config.frv"
166 source "extra/Configs/Config.h8300"
170 source "extra/Configs/Config.hppa"
174 source "extra/Configs/Config.i386"
178 source "extra/Configs/Config.i960"
182 source "extra/Configs/Config.ia64"
186 source "extra/Configs/Config.m68k"
190 source "extra/Configs/Config.metag"
194 source "extra/Configs/Config.nios"
198 source "extra/Configs/Config.nios2"
202 source "extra/Configs/Config.microblaze"
206 source "extra/Configs/Config.mips"
210 source "extra/Configs/Config.powerpc"
214 source "extra/Configs/Config.sh"
218 source "extra/Configs/Config.sh64"
222 source "extra/Configs/Config.sparc"
226 source "extra/Configs/Config.v850"
230 source "extra/Configs/Config.vax"
234 source "extra/Configs/Config.x86_64"
238 source "extra/Configs/Config.xtensa"
242 source "extra/Configs/Config.c6x"
246 source "extra/Configs/Config.arc"
249 config TARGET_SUBARCH
251 default "e500" if CONFIG_E500
252 default "classic" if CONFIG_CLASSIC
253 default "sh4" if CONFIG_SH4
254 default "" if CONFIG_386
255 default "i486" if CONFIG_486
256 default "i586" if CONFIG_586
257 default "i686" if CONFIG_686
260 source "extra/Configs/Config.in.arch"
264 menu "General Library Settings"
270 bool "Generate only Position Independent Code (PIC)"
272 depends on !HAVE_NO_PIC
274 If you wish to build all of uClibc as PIC objects, then answer Y here.
275 If you are unsure, then you should answer N.
277 config ARCH_HAS_NO_SHARED
280 config ARCH_HAS_NO_LDSO
282 select ARCH_HAS_NO_SHARED
284 config ARCH_HAS_UCONTEXT
288 bool "Enable shared libraries"
289 depends on !ARCH_HAS_NO_SHARED
292 If you wish to build uClibc with support for shared libraries then
293 answer Y here. If you only want to build uClibc as a static library,
296 config FORCE_SHAREABLE_TEXT_SEGMENTS
297 bool "Only load shared libraries which can share their text segment"
298 depends on HAVE_SHARED
301 If you answer Y here, the uClibc native shared library loader will
302 only load shared libraries, which do not need to modify any
303 non-writable segments. These libraries haven't set the DT_TEXTREL
304 tag in the dynamic section (==> objdump).
305 All your libraries must be compiled with -fPIC or -fpic, and all
306 assembler function must be written as position independent code (PIC).
307 Enabling this option will make uClibc's shared library loader a
308 little bit smaller and guarantee that no memory will be wasted by
309 badly coded shared libraries.
311 config LDSO_LDD_SUPPORT
312 bool "Native 'ldd' support"
313 depends on HAVE_SHARED
316 Enable all the code needed to support traditional ldd,
317 which executes the shared library loader to resolve all dependencies
318 and then provide a list of shared libraries that are required for an
319 application to function. Disabling this option will make uClibc's
320 shared library loader a little bit smaller.
321 Most people will answer Y.
323 config LDSO_CACHE_SUPPORT
324 bool "Enable library loader cache (ld.so.conf)"
325 depends on HAVE_SHARED
328 Enable this to make use of /etc/ld.so.conf, the shared library loader
329 cache configuration file to support for non-standard library paths.
330 After updating this file, it is necessary to run 'ldconfig' to update
331 the /etc/ld.so.cache shared library loader cache file.
333 config LDSO_PRELOAD_ENV_SUPPORT
334 bool "Enable library loader LD_PRELOAD environment"
335 depends on HAVE_SHARED
338 Enable this to make use of LD_PRELOAD environment variable.
339 A whitespace-separated list of additional, user-specified, ELF shared
340 libraries to be loaded before all others. This can be used to
341 selectively override functions in other shared libraries. For
342 set-user-ID/set-group-ID ELF binaries, only libraries in the standard
343 search directories that are also set-user-ID will be loaded.
345 config LDSO_PRELOAD_FILE_SUPPORT
346 bool "Enable library loader preload file (ld.so.preload)"
347 depends on HAVE_SHARED
349 Enable this to make use of /etc/ld.so.preload. This file contains a
350 whitespace separated list of shared libraries to be loaded before
353 config LDSO_BASE_FILENAME
354 string "Shared library loader naming prefix"
355 depends on HAVE_SHARED && (LDSO_CACHE_SUPPORT || LDSO_PRELOAD_FILE_SUPPORT)
358 If you wish to support both uClibc and glibc on the same system, it
359 is necessary to set this to something other than "ld.so" to avoid
360 conflicts with glibc, which also uses "ld.so". This prevents both
361 libraries from using the same /etc/ld.so.* files. If you wish to
362 support both uClibc and glibc on the same system then you should set
363 this to "ld-uClibc.so".
365 Most people will leave this set to the default of "ld.so".
367 WARNING: Changing the default prefix could cause problems with
370 config LDSO_STANDALONE_SUPPORT
371 bool "Dynamic linker stand-alone mode support"
372 depends on HAVE_SHARED
374 The dynamic linker can be run either indirectly through running some
375 dynamically linked program or library (in which case no command line
376 options to the dynamic linker can be passed and, in the ELF case, the
377 dynamic linker which is stored in the .interp section of the program
378 is executed) or directly by running:
380 /lib/ld-uClibc.so.* [OPTIONS] [PROGRAM [ARGUMENTS]]
382 Stand-alone execution is a prerequisite for adding prelink
383 capabilities to uClibc dynamic linker, as well useful for testing an
384 updated version of the dynamic linker without breaking the system.
386 config LDSO_PRELINK_SUPPORT
387 bool "Dynamic linker prelink support"
388 depends on HAVE_SHARED
389 select LDSO_STANDALONE_SUPPORT
391 The dynamic linker can be used in stand-alone mode by the prelink tool
392 for prelinking ELF shared libraries and binaries to speed up startup
393 time. It also is able to load and handle prelinked libraries and
396 config UCLIBC_STATIC_LDCONFIG
397 bool "Link ldconfig statically"
398 depends on HAVE_SHARED
401 Enable this option to statically link the ldconfig binary.
403 Making ldconfig static can be beneficial if you have a library
404 problem and need to use ldconfig to recover. Sometimes it is
405 preferable to instead keep the size of the system down, in which
406 case you should disable this option.
409 bool "Enable ELF RUNPATH tag support"
410 depends on HAVE_SHARED
411 default y if LDSO_CACHE_SUPPORT
413 ELF's may have dynamic RPATH/RUNPATH tags. These tags list paths
414 which extend the library search paths. They are really only useful
415 if a package installs libraries in non standard locations and
416 ld.so.conf support is disabled.
418 Usage of RUNPATH tags is not too common, so disabling this feature
419 should be safe for most people.
421 config LDSO_SAFE_RUNPATH
422 bool "Allow only RUNPATH beginning with /"
423 depends on LDSO_RUNPATH
426 Allow only absolute path in RPATH/RUNPATH.
428 config LDSO_SEARCH_INTERP_PATH
429 bool "Add ldso path to lib search path"
430 depends on HAVE_SHARED
433 The ldso is told where it is being executed from and can use that
434 path to find related core libraries. This is useful by default,
435 but can be annoying in a mixed development environment.
437 i.e. if the ldso is run from /foo/boo/ldso.so, it will start its
438 library search with /foo/boo/
440 If unsure, simply say Y here.
442 config LDSO_LD_LIBRARY_PATH
443 bool "Add LD_LIBRARY_PATH to lib search path"
444 depends on HAVE_SHARED
447 On hardened system it could be useful to disable the use of
448 LD_LIBRARY_PATH environment variable (a colon-separated list of
449 directories in which to search for ELF libraries at execution-time).
451 If unsure, simply say Y here.
453 config LDSO_NO_CLEANUP
454 bool "Disable automatic unloading of dynamically loaded shared objects"
455 depends on HAVE_SHARED
457 If you need complete allocation traces when debugging memory leaks
458 using Valgrind in a process that dynamically loads shared objects,
459 then answer Y here. Unlike glibc, uClibc unloads all dynamically
460 loaded shared objects when a process exits, which prevents Valgrind
461 from correctly resolving the symbols from the unloaded shared objects.
462 Unless you know you need this, you should answer N.
464 config UCLIBC_CTOR_DTOR
465 bool "Support global constructors and destructors"
468 If you wish to build uClibc with support for global constructor
469 (ctor) and global destructor (dtor) support, then answer Y here.
470 When ctor/dtor support is enabled, binaries linked with uClibc must
471 also be linked with crtbegin.o and crtend.o which are provided by gcc
472 (the "*startfile:" and "*endfile:" settings in your gcc specs file
473 may need to be adjusted to include these files). This support will
474 also add a small amount of additional size to each binary compiled vs
475 uClibc. If you will be using uClibc with C++, or if you need the gcc
476 __attribute__((constructor)) and __attribute__((destructor)) to work,
477 then you definitely want to answer Y here. If you don't need ctors
478 or dtors and want your binaries to be as small as possible, then
481 config LDSO_GNU_HASH_SUPPORT
482 bool "Enable GNU hash style support"
483 depends on HAVE_SHARED
485 Newest binutils support a new hash style named GNU-hash. The dynamic
486 linker will use the new GNU-hash section (.gnu.hash) for symbol lookup
487 if present into the ELF binaries, otherwise it will use the old SysV
488 hash style (.hash). This ensures that it is completely backward
490 Further, being the hash table implementation self-contained into each
491 executable and shared libraries, objects with mixed hash style can
492 peacefully coexist in the same process.
494 If you want to use this new feature, answer Y
497 prompt "Thread support"
498 #default UCLIBC_HAS_THREADS_NATIVE if (TARGET_alpha || TARGET_arm || TARGET_i386 || TARGET_mips || TARGET_powerpc || TARGET_sh || TARGET_sh64)
499 default HAS_NO_THREADS
501 If you want to compile uClibc with pthread support, then answer Y.
502 This will increase the size of uClibc by adding a bunch of locking
503 to critical data structures, and adding extra code to ensure that
504 functions are properly reentrant.
506 config HAS_NO_THREADS
509 Disable thread support.
511 config LINUXTHREADS_OLD
512 bool "older (stable) version of linuxthreads"
513 # linuxthreads and linuxthreads.old need nanosleep()
514 select UCLIBC_HAS_REALTIME
516 There are two versions of linuxthreads. The older (stable) version
517 has been in uClibc for quite a long time but hasn't seen too many
518 updates other than bugfixes.
521 config LINUXTHREADS_NEW
522 bool "slightly newer version of linuxthreads"
523 depends on ARCH_HAS_DEPRECATED_SYSCALLS
525 The new version has not been tested much, and lacks ports for arches
526 which glibc does not support (like bfin/frv/etc...), but is based on
527 the latest code from glibc, so it may be the only choice for the
528 newer ports (like alpha/amd64/64bit arches and hppa).
530 config UCLIBC_HAS_THREADS_NATIVE
531 bool "Native POSIX Threading (NPTL)"
532 select UCLIBC_HAS_TLS
533 select UCLIBC_HAS_STDIO_FUTEXES
534 select UCLIBC_HAS_REALTIME
535 # i386 has no lowlevellock support (yet) as opposed to i486 onward
536 depends on !CONFIG_386
538 If you want to compile uClibc with NPTL support, then answer Y.
540 IMPORTANT NOTE! NPTL requires a Linux 2.6 kernel, binutils
541 at least version 2.16 and GCC with at least version 4.1.0. NPTL
542 will not work with older versions of any above sources. If you
543 ignore any of these guidelines, you do so at your own risk. Do
544 not ask for help on any of the development mailing lists.
546 !!!! WARNING !!!! BIG FAT WARNING !!!! REALLY BIG FAT WARNING !!!!
548 This is experimental code and at times it may not even build and
549 even if it does it might decide to do random damage. This code is
550 potentially hazardous to your health and sanity. It will remain
551 that way until further notice at which point this notice will
552 disappear. Thank you for your support and for not smoking.
556 config UCLIBC_HAS_THREADS
557 def_bool y if !HAS_NO_THREADS
559 config UCLIBC_HAS_TLS
560 bool "Thread-Local Storage"
561 depends on UCLIBC_HAS_THREADS_NATIVE
563 If you want to enable TLS support then answer Y.
564 This is fast an efficient way to store per-thread local data
565 which is not on stack. It needs __thread support enabled in
568 config PTHREADS_DEBUG_SUPPORT
569 bool "Build pthreads debugging support"
570 depends on UCLIBC_HAS_THREADS
572 Say Y here if you wish to be able to debug applications that use
573 uClibc's pthreads library. By enabling this option, a library
574 named libthread_db will be built. This library will be dlopen()'d
575 by gdb and will allow gdb to debug the threads in your application.
577 IMPORTANT NOTE! Because gdb must dlopen() the libthread_db library,
578 you must compile gdb with uClibc in order for pthread debugging to
581 If you are doing development and want to debug applications using
582 uClibc's pthread library, answer Y. Otherwise, answer N.
585 config UCLIBC_HAS_SYSLOG
586 bool "Syslog support"
588 depends on UCLIBC_HAS_NETWORK_SUPPORT
589 select UCLIBC_HAS_SOCKET
591 Support sending messages to the system logger.
592 This requires socket-support.
594 config UCLIBC_HAS_LFS
595 bool "Large File Support"
598 If you wish to build uClibc with support for accessing large files
599 (i.e. files greater then 2 GiB) then answer Y. Do not enable this
600 if you are using an older Linux kernel (2.0.x) that lacks large file
601 support. Enabling this option will increase the size of uClibc.
604 prompt "Malloc Implementation"
605 default MALLOC if ! ARCH_USE_MMU
606 default MALLOC_STANDARD if ARCH_USE_MMU
611 "malloc" use mmap for all allocations and so works very well on
612 MMU-less systems that do not support the brk() system call. It is
613 pretty smart about reusing already allocated memory, and minimizing
615 This is the default for uClinux MMU-less systems.
620 "malloc-simple" is trivially simple and slow as molasses. It
621 was written from scratch for uClibc, and is the simplest possible
622 (and therefore smallest) malloc implementation.
624 This uses only the mmap() system call to allocate and free memory,
625 and does not use the brk() system call at all, making it a fine
626 choice for MMU-less systems with very limited memory. It's 100%
627 standards compliant, thread safe, very small, and releases freed
628 memory back to the OS immediately rather than keeping it in the
629 process's heap for reallocation. It is also VERY SLOW.
631 config MALLOC_STANDARD
632 bool "malloc-standard"
633 depends on ARCH_USE_MMU
635 "malloc-standard" is derived from the public domain dlmalloc
636 implementation by Doug Lea. It is quite fast, and is pretty smart
637 about reusing already allocated memory, and minimizing memory
638 wastage. This uses brk() for small allocations, while using mmap()
639 for larger allocations. This is the default malloc implementation
642 If unsure, answer "malloc-standard".
646 config MALLOC_GLIBC_COMPAT
647 bool "Malloc returns live pointer for malloc(0)"
649 The behavior of malloc(0) is listed as implementation-defined by
650 SuSv3. Glibc returns a valid pointer to something, while uClibc
651 normally returns NULL. I personally feel glibc's behavior is
652 not particularly safe, and allows buggy applications to hide very
655 When this option is enabled, uClibc will act just like glibc, and
656 return a live pointer when someone calls malloc(0). This pointer
657 provides a malloc'ed area with a size of 1 byte. This feature is
658 mostly useful when dealing with applications using autoconf's broken
659 AC_FUNC_MALLOC macro (which redefines malloc as rpl_malloc if it
660 does not detect glibc style returning-a-valid-pointer-for-malloc(0)
661 behavior). Most people can safely answer N.
663 config UCLIBC_HAS_OBSTACK
664 bool "Obstack Support (gnu extension)"
666 When this option is enabled, uClibc will provide support for obstacks.
667 An obstack is a structure in which memory can be dynamically allocated
668 as a 'stack of objects'. Many programs need this GNU extention and
669 you should say Y if you are using any. Otherwise, say N to save some
672 config UCLIBC_DYNAMIC_ATEXIT
673 bool "Dynamic atexit() Support"
676 When this option is enabled, uClibc will support an infinite number,
677 of atexit() and on_exit() functions, limited only by your available
678 memory. This can be important when uClibc is used with C++, since
679 global destructors are implemented via atexit(), and it is quite
680 possible to exceed the default number when this option is disabled.
681 Enabling this option adds a few bytes, and more significantly makes
682 atexit and on_exit depend on malloc, which can be bad when compiling
685 Unless you use uClibc with C++, you should probably answer N.
688 bool "Old (visible) atexit Support"
690 Enable this option if you want to update from 0.9.28 to git/0.9.29,
691 else you will be missing atexit() until you rebuild all apps.
693 config UCLIBC_SUSV2_LEGACY
694 bool "Enable SuSv2 LEGACY functions"
696 Enable this option if you want to have SuSv2 LEGACY functions
697 Currently applies to:
701 WARNING! ABI incompatibility.
703 config UCLIBC_SUSV3_LEGACY
704 bool "Enable SuSv3 LEGACY functions"
710 Enable this option if you want to have SuSv3 LEGACY functions
711 in the library, else they are replaced by SuSv3 proposed macros.
712 Currently applies to:
714 bcmp, bcopy, bzero, index, rindex, ftime,
715 bsd_signal, (ecvt), (fcvt), gcvt, (getcontext),
716 (getwd), (makecontext),
717 mktemp, (pthread_attr_getstackaddr), (pthread_attr_setstackaddr),
718 scalb, (setcontext), (swapcontext), ualarm, usleep,
721 WARNING! ABI incompatibility.
723 config UCLIBC_HAS_CONTEXT_FUNCS
724 bool "Use obsolescent context control functions"
725 depends on UCLIBC_SUSV3_LEGACY && ARCH_HAS_UCONTEXT
727 Add into library the SuSv3 obsolescent functions used for context
728 control. The setcontext family allows the implementation in C of
729 advanced control flow patterns such as iterators, fibers, and
730 coroutines. They may be viewed as an advanced version of
731 setjmp/longjmp; whereas the latter allows only a single non-local jump
732 up the stack, setcontext allows the creation of multiple cooperative
733 threads of control, each with its own stack.
734 These functions are: setcontext, getcontext, makecontext, swapcontext.
736 config UCLIBC_SUSV3_LEGACY_MACROS
737 bool "Enable SuSv3 LEGACY macros"
739 Enable this option if you want to have SuSv3 LEGACY macros.
740 Currently applies to bcopy/bzero/bcmp/index/rindex et al.
741 WARNING! ABI incompatibility.
743 config UCLIBC_SUSV4_LEGACY
744 bool "Enable SuSv4 LEGACY or obsolescent functions"
746 Enable this option if you want to have SuSv4 LEGACY functions
747 and macros in the library.
748 Currently applies to:
751 _longjmp, _setjmp, _tolower, _toupper, ftw, getitimer,
752 gettimeofday, isascii, pthread_getconcurrency,
753 pthread_setconcurrency, setitimer, setpgrp, sighold,
754 sigignore, sigpause, sigrelse, sigset, siginterrupt,
755 tempnam, toascii, ulimit.
758 asctime, asctime_r, ctime, ctime_r, gets, rand_r,
761 WARNING! ABI incompatibility.
763 config UCLIBC_STRICT_HEADERS
764 bool "Hide structures and constants for unsupported features"
766 Hide structures and constants in headers that should not be used,
767 because the respective feature is disabled.
769 WARNING! enabling this option requires to patch many faulty apps,
770 since they make (wrongly) use of these structures/constants,
771 although the feature was disabled.
773 config UCLIBC_HAS_STUBS
774 bool "Provide stubs for unavailable functionality"
776 With this option uClibc provides non-functional stubs for
777 functions which are impossible to implement on the target
778 architecture. Otherwise, such functions are simply omitted.
780 config UCLIBC_HAS_SHADOW
781 bool "Shadow Password Support"
784 Answer N if you do not need shadow password support.
785 Most people will answer Y.
787 config UCLIBC_HAS_PROGRAM_INVOCATION_NAME
788 bool "Support for program_invocation_name"
790 Support for the GNU-specific program_invocation_name and
791 program_invocation_short_name strings. Some GNU packages
792 (like tar and coreutils) utilize these for extra useful
793 output, but in general are not required.
795 At startup, these external strings are automatically set
796 up based on the value of ARGV[0].
798 If unsure, just answer N.
800 config UCLIBC_HAS___PROGNAME
801 bool "Support for __progname"
804 Some packages (like openssh) like to peek into internal libc
805 symbols to make their output a bit more user friendly.
807 At startup, __progname is automatically set up based on the
810 If unsure, just answer N.
812 config UCLIBC_HAS_PTY
813 bool "Support for pseudo-terminals"
816 This enables support for pseudo-terminals (see man 4 pts
819 If unsure, just answer Y.
822 bool "Assume that /dev/pts is a devpts or devfs file system"
824 depends on UCLIBC_HAS_PTY
826 Enable this if /dev/pts is on a devpts or devfs filesystem. Both
827 these filesystems automatically manage permissions on the /dev/pts
828 devices. You may need to mount your devpts or devfs filesystem on
829 /dev/pts for this to work.
831 Most people should answer Y.
833 config UNIX98PTY_ONLY
834 bool "Support only Unix 98 PTYs"
836 depends on UCLIBC_HAS_PTY
838 If you want to support only Unix 98 PTYs enable this. Some older
839 applications may need this disabled and will thus use legacy BSD
840 style PTY handling which is more complex and also bigger than
841 Unix 98 PTY handling.
843 For most current programs, you can generally answer Y.
846 config UCLIBC_HAS_GETPT
847 bool "Support getpt() (glibc-compat)"
848 depends on UCLIBC_HAS_PTY
850 Some packages may need getpt().
851 All of those are non-standard and can be considered
852 GNU/libc compatibility.
853 Either use posix_openpt() or just open /dev/ptmx yourself.
855 If unsure, just say N.
859 # Have to use __libc_ptyname{1,2}[] and related bloat
860 config UCLIBC_HAS_GETPT
864 config UCLIBC_HAS_LIBUTIL
865 bool "Provide libutil library and functions"
866 depends on UCLIBC_HAS_PTY
868 Provide a libutil library.
869 This non-standard conforming library provides the following
872 forkpty(): combines openpty(), fork(2), and login_tty() to
873 create a new process operating in a pseudo-terminal.
874 login(): write utmp and wtmp entries
875 login_tty(): prepares for a login on the tty fd by creating a
876 new session, making fd the controlling terminal for
877 the calling process, setting fd to be the standard
878 input, output, and error streams of the current
879 process, and closing fd.
880 logout(): write utmp and wtmp entries
881 logwtmp(): constructs a utmp structure and calls updwtmp() to
882 append the structure to the utmp file.
883 openpty(): finds an available pseudo-terminal and returns
884 file descriptors for the master and slave
886 This library adds about 3k-4k to your system.
888 config UCLIBC_HAS_TM_EXTENSIONS
889 bool "Support 'struct tm' timezone extension fields"
892 Enabling this option adds fields to 'struct tm' in time.h for
893 tracking the number of seconds east of UTC, and an abbreviation for
894 the current timezone. These fields are not specified by the SuSv3
895 standard, but they are commonly used in both GNU and BSD application
898 To strictly follow the SuSv3 standard, leave this disabled.
899 Most people will probably want to answer Y.
901 config UCLIBC_HAS_TZ_CACHING
902 bool "Enable caching of the last valid timezone 'TZ' string"
905 Answer Y to enable caching of the last valid 'TZ' string describing
906 the timezone setting. This allows a quick string compare to avoid
907 repeated parsing of unchanged 'TZ' strings when tzset() is called.
909 Most people will answer Y.
911 config UCLIBC_HAS_TZ_FILE
912 bool "Enable '/etc/TZ' file support to set a default timezone (uClibc-specific)"
915 Answer Y to enable the setting of a default timezone for uClibc.
917 Ordinarily, uClibc gets the timezone information exclusively from the
918 'TZ' environment variable. In particular, there is no support for
919 the zoneinfo directory tree or the /etc/timezone file used by glibc.
921 With this option enabled, uClibc will use the value stored in the
922 file '/etc/TZ' (default path) to obtain timezone information if the
923 'TZ' environment variable is missing or has an invalid value. The
924 file consists of a single line (newline required) of text describing
925 the timezone in the format specified for the TZ environment variable.
927 Doing 'echo CST6CDT > /etc/TZ' is enough to create a valid file.
929 http://www.opengroup.org/onlinepubs/007904975/basedefs/xbd_chap08.html
930 for details on valid settings of 'TZ'.
932 Most people will answer Y.
934 config UCLIBC_HAS_TZ_FILE_READ_MANY
935 bool "Repeatedly read the '/etc/TZ' file"
936 depends on UCLIBC_HAS_TZ_FILE
939 Answer Y to enable repeated reading of the '/etc/TZ' file even after
940 a valid value has been read. This incurs the overhead of an
941 open/read/close for each tzset() call (explicit or implied). However,
942 setting this will allow applications to update their timezone
943 information if the contents of the file change.
945 Most people will answer Y.
947 config UCLIBC_TZ_FILE_PATH
948 string "Path to the 'TZ' file for setting the global timezone"
949 depends on UCLIBC_HAS_TZ_FILE
952 This is the path to the 'TZ' file.
954 Most people will use the default of '/etc/TZ'.
956 config UCLIBC_FALLBACK_TO_ETC_LOCALTIME
957 bool "Use /etc/localtime as a fallback"
958 depends on UCLIBC_HAS_TZ_FILE
961 Answer Y to try to use /etc/localtime file.
962 On glibc systems this file (if it is in TZif2 format)
963 contains timezone string at the end.
965 Most people will answer Y.
969 menu "Advanced Library Settings"
971 config UCLIBC_PWD_BUFFER_SIZE
972 int "Buffer size for getpwnam() and friends"
976 This sets the value of the buffer size for getpwnam() and friends.
977 By default, this is 256. (For reference, glibc uses 1024).
978 The value can be found using sysconf() with the _SC_GETPW_R_SIZE_MAX
981 config UCLIBC_GRP_BUFFER_SIZE
982 int "Buffer size for getgrnam() and friends"
986 This sets the value of the buffer size for getgrnam() and friends.
987 By default, this is 256. (For reference, glibc uses 1024).
988 The value can be found using sysconf() with the _SC_GETGR_R_SIZE_MAX
991 comment "Support various families of functions"
993 config UCLIBC_LINUX_MODULE_26
994 bool "Linux kernel module functions (2.6)"
997 delete_module, init_module
998 are used in linux for loadable kernel modules.
1000 Say N if you do not use kernel modules.
1002 config UCLIBC_LINUX_MODULE_24
1003 bool "Linux kernel module functions (<2.6)"
1004 depends on !TARGET_bfin && !TARGET_c6x
1006 create_module, query_module
1007 are used in linux (prior to 2.6) for loadable kernel modules.
1009 Say N if you do not use kernel modules, or you only support
1012 config UCLIBC_LINUX_SPECIFIC
1013 bool "Linux specific functions"
1016 accept4(), bdflush(),
1017 capget(), capset(), eventfd(), fallocate(),
1018 fstatfs(), inotify_*(), ioperm(), iopl(),
1019 madvise(), modify_ldt(), pipe2(), personality(),
1020 prctl()/arch_prctl(), pivot_root(), modify_ldt(),
1021 ppoll(), readahead(), reboot(), remap_file_pages(),
1022 sched_getaffinity(), sched_setaffinity(), sendfile(),
1023 setfsgid(), setfsuid(), setresgid(), setresuid(),
1024 splice(), vmsplice(), tee(), signalfd(), statfs(),
1025 swapoff(), swapon(), sync_file_range(), _sysctl(),
1026 sysinfo(), timerfd_*(), vhangup(), umount(), umount2()
1028 config UCLIBC_HAS_GNU_ERROR
1029 bool "Support GNU extensions for error-reporting"
1032 Support for the GNU-specific error(), error_at_line(),
1033 void (* error_print_progname)(), error_message_count
1034 functions and variables. Some GNU packages
1035 utilize these for extra useful output, but in general
1038 If unsure, just answer N.
1040 config UCLIBC_BSD_SPECIFIC
1041 bool "BSD specific functions"
1044 mincore(), getdomainname(), setdomainname()
1048 config UCLIBC_HAS_BSD_ERR
1049 bool "BSD err functions"
1052 These functions are non-standard BSD extensions.
1053 err(), errx(), warn(), warnx(), verr(), verrx(), vwarn(), vwarnx()
1057 config UCLIBC_HAS_OBSOLETE_BSD_SIGNAL
1058 bool "BSD obsolete signal functions"
1060 These functions are provided as a compatibility interface for
1061 programs that make use of the historical System V signal API.
1062 This API is obsolete:
1063 new applications should use the POSIX signal API (sigaction(2),
1064 sigprocmask(2), etc.).
1067 sigset(), sighold(), sigrelse(), sigignore()
1071 config UCLIBC_HAS_OBSOLETE_SYSV_SIGNAL
1072 bool "SYSV obsolete signal functions"
1074 Use of sysv_signal() should be avoided; use sigaction(2) instead.
1078 config UCLIBC_NTP_LEGACY
1079 bool "ntp_*() aliases"
1081 Provide legacy aliases for ntp functions:
1082 ntp_adjtime(), ntp_gettime()
1084 It is safe to say N here.
1086 config UCLIBC_SV4_DEPRECATED
1087 bool "Enable SVr4 deprecated functions"
1089 These functions are DEPRECATED in System V release 4.
1090 Say N unless you desparately need one of the functions below:
1092 ustat() [use statfs(2) in your code instead]
1094 config UCLIBC_HAS_REALTIME
1095 bool "Realtime-related family of SUSv functions"
1098 These functions are part of the Timers option and need not
1099 be available on all implementations.
1100 Includes AIO, message-queue, scheduler, semaphore functions:
1115 clock_getres(), clock_gettime(), clock_settime()
1117 mlockall(), munlockall()
1129 sched_get_priority_max(), sched_get_priority_min()
1130 sched_getscheduler()
1131 sched_rr_get_interval()
1133 sched_setscheduler()
1140 sem_trywait(), sem_wait()
1143 sigtimedwait(), sigwaitinfo()
1146 timer_getoverrun(), timer_gettime(), timer_settime()
1148 config UCLIBC_HAS_ADVANCED_REALTIME
1149 bool "Advanced realtime-related family of SUSv functions"
1151 depends on UCLIBC_HAS_REALTIME
1153 These functions are part of the Timers option and need not
1154 be available on all implementations.
1156 clock_getcpuclockid()
1165 posix_spawnattr_destroy(), posix_spawnattr_init()
1166 posix_spawnattr_getflags(), posix_spawnattr_setflags()
1167 posix_spawnattr_getpgroup(), posix_spawnattr_setpgroup()
1168 posix_spawnattr_getschedparam(), posix_spawnattr_setschedparam()
1169 posix_spawnattr_getschedpolicy(), posix_spawnattr_setschedpolicy()
1170 posix_spawnattr_getsigdefault(), posix_spawnattr_setsigdefault()
1171 posix_spawnattr_getsigmask(), posix_spawnattr_setsigmask()
1172 posix_spawn_file_actions_addclose()
1173 posix_spawn_file_actions_adddup2()
1174 posix_spawn_file_actions_addopen()
1175 posix_spawn_file_actions_destroy()
1176 posix_spawn_file_actions_init()
1179 posix_typed_mem_get_info()
1180 pthread_mutex_timedlock()
1183 #config UCLIBC_HAS_TERMIOS
1184 # bool "termios functions"
1187 # Get and set terminal attributes, line control, get and set baud
1189 # termios(), tcgetattr(), tcsetattr(), tcsendbreak(), tcdrain(),
1190 # tcflush(), tcflow(), cfmakeraw(), cfgetospeed(), cfgetispeed(),
1191 # cfsetispeed(), cfsetospeed(), cfsetspeed()
1195 config UCLIBC_HAS_EPOLL
1199 epoll_create(), epoll_ctl(), epoll_wait() functions.
1201 config UCLIBC_HAS_XATTR
1202 bool "Extended Attributes"
1205 Extended Attributes support.
1220 Say N unless you need support for extended attributes and the
1221 filesystems do actually support them.
1223 config UCLIBC_HAS_PROFILING
1224 bool "Profiling support"
1227 gcc's -finstrument-functions needs these.
1229 Most people can safely answer N.
1231 config UCLIBC_HAS_CRYPT_IMPL
1232 bool "libcrypt support"
1235 libcrypt contains crypt(), setkey() and encrypt()
1237 config UCLIBC_HAS_SHA256_CRYPT_IMPL
1238 bool "libcrypt SHA256 support"
1239 depends on UCLIBC_HAS_CRYPT_IMPL
1241 This adds support for SHA256 password hashing via the crypt() function.
1242 Say N here if you do not need SHA256 crypt support.
1244 config UCLIBC_HAS_SHA512_CRYPT_IMPL
1245 bool "libcrypt SHA512 support"
1246 depends on UCLIBC_HAS_CRYPT_IMPL
1248 This adds support for SHA512 password hashing via the crypt() function.
1249 Say N here if you do not need SHA512 crypt support.
1251 config UCLIBC_HAS_CRYPT_STUB
1252 bool "libcrypt stubs"
1254 depends on !UCLIBC_HAS_CRYPT_IMPL
1256 Standards mandate that crypt(3) provides a stub if it is unavailable.
1257 If you enable this option then stubs for
1258 crypt(), setkey() and encrypt()
1259 will be provided in a small libcrypt.
1261 config UCLIBC_HAS_CRYPT
1263 depends on UCLIBC_HAS_CRYPT_IMPL || UCLIBC_HAS_CRYPT_STUB
1266 menuconfig UCLIBC_HAS_NETWORK_SUPPORT
1267 bool "Networking Support"
1270 Say N here if you do not need network support.
1272 if UCLIBC_HAS_NETWORK_SUPPORT
1273 config UCLIBC_HAS_SOCKET
1274 bool "Socket support"
1277 If you want to include support for sockets then answer Y.
1279 config UCLIBC_HAS_IPV4
1280 bool "IP version 4 support"
1282 select UCLIBC_HAS_SOCKET
1284 If you want to include support for the Internet Protocol
1285 (IP version 4) then answer Y.
1287 Most people will say Y.
1289 config UCLIBC_HAS_IPV6
1290 bool "IP version 6 support"
1291 select UCLIBC_HAS_SOCKET
1293 If you want to include support for the next version of the Internet
1294 Protocol (IP version 6) then answer Y.
1296 Most people should answer N.
1298 config UCLIBC_HAS_RPC
1299 bool "Remote Procedure Call (RPC) support"
1300 # RPC+socket-ipvX doesn't currently work.
1301 depends on UCLIBC_HAS_IPV4 || UCLIBC_HAS_IPV6
1303 If you want to include RPC support, enable this. RPC is rarely used
1304 for anything except for the NFS filesystem. Unless you plan to use
1305 NFS, you can probably leave this set to N and save some space.
1307 If you need to use NFS then you should answer Y.
1309 config UCLIBC_HAS_FULL_RPC
1310 bool "Full RPC support"
1311 depends on UCLIBC_HAS_RPC
1312 default y if !HAVE_SHARED
1314 Normally we enable just enough RPC support for things like rshd and
1315 nfs mounts to work. If you find you need the rest of the RPC stuff,
1316 then enable this option. Most people can safely answer N.
1318 config UCLIBC_HAS_REENTRANT_RPC
1319 bool "Reentrant RPC support"
1320 depends on UCLIBC_HAS_RPC
1321 default y if !HAVE_SHARED
1323 Most packages utilize the normal (non-reentrant) RPC functions, but
1324 some (like exportfs from nfs-utils) need these reentrant versions.
1326 Most people can safely answer N.
1328 config UCLIBC_USE_NETLINK
1329 bool "Use netlink to query interfaces"
1330 depends on UCLIBC_HAS_SOCKET
1332 In newer versions of Linux (2.4.17+), support was added for querying
1333 network device information via netlink rather than the old style
1334 ioctl's. Most of the time, the older ioctl style is sufficient (and
1335 it is smaller than netlink), but if you find that not all of your
1336 devices are being returned by the if_nameindex() function, you will
1337 have to use the netlink implementation.
1339 Most people can safely answer N.
1341 config UCLIBC_SUPPORT_AI_ADDRCONFIG
1342 bool "Support the AI_ADDRCONFIG flag"
1343 depends on UCLIBC_USE_NETLINK
1345 The implementation of AI_ADDRCONFIG is aligned with the glibc
1346 implementation using netlink to query interfaces to find both
1347 ipv4 and ipv6 support. This is only needed if an application uses
1348 the AI_ADDRCONFIG flag.
1350 Most people can safely answer N.
1352 config UCLIBC_HAS_BSD_RES_CLOSE
1353 bool "Support res_close() (bsd-compat)"
1355 Answer Y if you desperately want to support BSD compatibility in
1358 Most people will say N.
1360 config UCLIBC_HAS_COMPAT_RES_STATE
1361 bool "Use compatible but bloated _res"
1364 Answer Y if you build network utilities and they muck with resolver
1365 internals a lot (_res global structure). uclibc does not use most
1366 of _res.XXX fields, and with this option OFF they won't even exist.
1367 Which will make e.g. dig build fail.
1368 Answering N saves around 400 bytes in bss.
1370 config UCLIBC_HAS_EXTRA_COMPAT_RES_STATE
1371 bool "Use extra compatible but extra bloated _res"
1373 Answer Y if selecting UCLIBC_HAS_COMPAT_RES_STATE is not enough.
1374 As far as I can say, this should never be needed.
1376 config UCLIBC_HAS_RESOLVER_SUPPORT
1377 bool "DNS resolver functions"
1378 select UCLIBC_HAS_COMPAT_RES_STATE
1379 depends on UCLIBC_HAS_IPV4 || UCLIBC_HAS_IPV6
1381 Provide implementations for DNS resolver functions.
1382 In particular, the following functions will be added to the
1385 ns_skiprr, ns_initparse, ns_parserr, ns_msg_getflag,
1386 res_mkquery, res_init, res_ninit, res_close, res_nclose
1387 res_query, res_search, res_querydomain,
1389 ns_name_uncompress, ns_name_ntop, ns_name_pton, ns_name_unpack,
1390 ns_name_pack, ns_name_compress, ns_name_skip, dn_skipname,
1391 ns_get16, ns_get32, ns_put16, ns_put32
1393 config UCLIBC_HAS_LIBRESOLV_STUB
1394 bool "Provide libresolv stub"
1396 Provide a dummy resolv library.
1398 config UCLIBC_HAS_LIBNSL_STUB
1399 bool "Provide libnsl stub"
1401 Provide a dummy nsl library.
1406 menu "String and Stdio Support"
1408 config UCLIBC_HAS_STRING_GENERIC_OPT
1409 bool "Use faster (but larger) generic string functions"
1412 Answer Y to use the (tweaked) glibc generic string functions.
1414 In general, they are faster (but 3-5K larger) than the base
1415 uClibc string functions which are optimized solely for size.
1417 Many people will answer Y.
1419 config UCLIBC_HAS_STRING_ARCH_OPT
1420 bool "Use arch-specific assembly string functions (where available)"
1423 Answer Y to use any archtecture-specific assembly language string
1424 functions available for this target plaform.
1426 Note that assembly implementations are not available for all string
1427 functions, so some generic (written in C) string functions may
1430 These are small and fast, the only reason _not_ to say Y here is
1431 for debugging purposes.
1433 config UCLIBC_HAS_STDIO_FUTEXES
1434 bool "Use futexes for multithreaded I/O locking"
1435 depends on UCLIBC_HAS_THREADS_NATIVE
1437 If you want to compile uClibc to use futexes for low-level
1438 I/O locking, answer Y. Otherwise, answer N.
1440 config UCLIBC_HAS_CTYPE_TABLES
1441 bool "Use Table Versions Of 'ctype.h' Functions."
1444 Answer Y to use table versions of the 'ctype.h' functions.
1445 While the non-table versions are often smaller when building
1446 statically linked apps, they work only in stub locale mode.
1448 Most people will answer Y.
1450 config UCLIBC_HAS_CTYPE_SIGNED
1451 bool "Support Signed Characters In 'ctype.h' Functions."
1452 depends on UCLIBC_HAS_CTYPE_TABLES
1455 Answer Y to enable support for passing signed char values to
1456 the 'ctype.h' functions. ANSI/ISO C99 and SUSv3 specify that
1457 these functions are only defined for unsigned char values and
1458 EOF. However, glibc allows negative signed char values as well
1459 in order to support 'broken old programs'.
1461 Most people will answer Y.
1464 prompt "ctype argument checking"
1465 depends on UCLIBC_HAS_CTYPE_TABLES
1466 default UCLIBC_HAS_CTYPE_UNSAFE
1468 Please select the invalid arg behavior you want for the 'ctype'
1471 The 'ctype' functions are now implemented using table lookups, with
1472 the arg being the index. This can result in incorrect memory accesses
1473 or even segfaults for args outside of the allowed range.
1475 NOTE: This only affects the 'ctype' _functions_. It does not affect
1476 the macro implementations.
1478 config UCLIBC_HAS_CTYPE_UNSAFE
1479 bool "Do not check -- unsafe"
1481 config UCLIBC_HAS_CTYPE_CHECKED
1482 bool "Detect and handle appropriately"
1484 config UCLIBC_HAS_CTYPE_ENFORCED
1485 bool "Issue a diagnostic and abort()"
1490 config UCLIBC_HAS_WCHAR
1491 bool "Wide Character Support"
1493 Answer Y to enable wide character support. This will make uClibc
1494 much larger. It is also currently required for locale support.
1496 Most people will answer N.
1498 config UCLIBC_HAS_LOCALE
1499 bool "Locale Support"
1500 select UCLIBC_HAS_WCHAR
1501 select UCLIBC_HAS_CTYPE_TABLES
1503 uClibc now has full ANSI/ISO C99 locale support (except for
1504 wcsftime() and collating items in regex). Be aware that enabling
1505 this option will make uClibc much larger.
1507 Enabling UCLIBC_HAS_LOCALE with the default set of supported locales
1508 (169 UTF-8 locales, and 144 locales for other codesets) will enlarge
1509 uClibc by around 300k. You can reduce this size by building your own
1510 custom set of locate data (see extra/locale/LOCALES for details).
1512 uClibc's locale support is still under development. For example,
1513 codesets using shift states are not currently supported. Support is
1514 planned in the next iteration of locale support.
1516 Answer Y to enable locale support. Most people will answer N.
1520 prompt "Locale data"
1521 depends on UCLIBC_HAS_LOCALE
1522 default UCLIBC_BUILD_ALL_LOCALE
1524 config UCLIBC_BUILD_ALL_LOCALE
1526 depends on UCLIBC_HAS_LOCALE
1528 This builds all the locales that are available on your
1531 config UCLIBC_BUILD_MINIMAL_LOCALE
1532 bool "Only selected locales"
1533 depends on UCLIBC_HAS_LOCALE
1535 If you do not need all locales that are available on your
1536 host-box, then set this to 'Y'.
1538 config UCLIBC_PREGENERATED_LOCALE_DATA
1539 bool "Use Pre-generated Locale Data"
1540 depends on UCLIBC_HAS_LOCALE && !TARGET_metag
1542 Use pre-built locale data.
1544 Note that these pregenerated locales are sensitive to your
1545 target architecture (endianess, bitcount).
1547 Saying N here is highly recommended.
1551 config UCLIBC_BUILD_MINIMAL_LOCALES
1552 string "locales to use"
1553 depends on UCLIBC_BUILD_MINIMAL_LOCALE
1556 Space separated list of locales to use.
1563 config UCLIBC_DOWNLOAD_PREGENERATED_LOCALE_DATA
1564 bool "Automagically Download the Pre-generated Locale Data (if necessary)"
1565 depends on UCLIBC_PREGENERATED_LOCALE_DATA
1567 If you would like the build process to use 'wget' to automatically
1568 download the pregenerated locale data, enable this option. Otherwise
1569 you will need to obtain the locale data yourself from:
1570 http://www.uclibc.org/downloads/uClibc-locale-*.tgz
1571 and place the uClibc-locale-*.tgz tarball in the extra/locale/
1574 Note that the use of pregenerated locale data is discouraged.
1576 config UCLIBC_HAS_XLOCALE
1577 bool "Extended Locale Support (experimental/incomplete)"
1578 depends on UCLIBC_HAS_LOCALE
1580 Answer Y to enable extended locale support similar to that provided
1581 by glibc. This is primarily intended to support libstd++
1583 However, it also allows thread-specific locale selection via
1586 Most people will answer N.
1588 config UCLIBC_HAS_HEXADECIMAL_FLOATS
1589 bool "Support hexadecimal float notation"
1590 depends on UCLIBC_HAS_CTYPE_TABLES
1591 depends on UCLIBC_HAS_FLOATS
1593 Answer Y to enable support for hexadecimal float notation in the
1594 (wchar and) char string to floating point conversion functions, as
1595 well as support for the %a and %A conversion specifiers in the
1596 *printf() and *scanf() functions.
1598 Most people will answer N.
1600 config UCLIBC_HAS_GLIBC_DIGIT_GROUPING
1601 bool "Support glibc's \"'\" flag for allowing locale-specific digit grouping"
1602 depends on UCLIBC_HAS_LOCALE
1603 depends on UCLIBC_HAS_FLOATS
1605 Answer Y to enable support for glibc's \"'\" flag for allowing
1606 locale-specific digit grouping in base 10 integer conversions and
1607 appropriate floating point conversions in the *printf() and *scanf()
1610 Most people will answer N.
1612 config UCLIBC_HAS_SCANF_LENIENT_DIGIT_GROUPING
1613 bool "Do not require digit grouping when the \"'\" flag is specified"
1614 depends on UCLIBC_HAS_GLIBC_DIGIT_GROUPING
1617 Answer Y to make digit grouping optional when the \"'\" flag is
1619 This is the standard glibc behavior. If the initial string of digits
1620 exceeds the maximum group number, the input will be treated as a
1621 normal non-grouped number.
1623 Most people will answer N.
1625 config UCLIBC_HAS_GLIBC_CUSTOM_PRINTF
1626 bool "Support glibc's register_printf_function() (glibc-compat)"
1627 depends on !USE_OLD_VFPRINTF
1629 Answer Y to support glibc's register_printf_function() to allow an
1630 application to add its own printf conversion specifiers.
1631 parse_printf_format() is also enabled.
1633 NOTE: Limits the number or registered specifiers to 10.
1634 NOTE: Requires new conversion specifiers to be ASCII
1635 characters (0-0x7f). This is to avoid problems with processing
1636 format strings in locales with different multibyte conversions.
1638 Most people will answer N.
1640 config USE_OLD_VFPRINTF
1641 bool "Use the old vfprintf implementation"
1642 depends on !UCLIBC_HAS_WCHAR
1644 Set to true to use the old vfprintf instead of the new. This is
1645 roughly C89 compliant with some extensions, and is much smaller.
1646 However, it does not support wide chars, positional args, or glibc
1647 custom printf specifiers.
1649 Most people will answer N.
1651 config UCLIBC_PRINTF_SCANF_POSITIONAL_ARGS
1652 int "Maximum number of positional args. Either 0 or >= 9."
1653 depends on !USE_OLD_VFPRINTF
1656 Set the maximum number of positional args supported by the
1657 printf/scanf functions. The Single Unix Specification Version 3
1658 requires a minimum value of 9. Setting this to a value lower than
1659 9 will disable positional arg support and cause the NL_ARGMAX macro
1660 in limits.h to be #undef'd.
1662 WARNING! The workspace to support positional args is currently
1663 allocated on the stack. You probably don't want to set
1664 this to too high a value.
1666 Most people will answer 9.
1669 prompt "Stdio buffer size"
1670 default UCLIBC_HAS_STDIO_BUFSIZ_4096
1672 Please select a value for BUFSIZ. This will be used by the
1673 stdio subsystem as the default buffer size for a file, and
1674 affects fopen(), setvbuf(), etc.
1676 NOTE: Setting this to 'none' will disable buffering completely.
1677 However, BUFSIZ will still be defined in stdio.h as 256 because
1678 many applications use this value.
1680 config UCLIBC_HAS_STDIO_BUFSIZ_NONE
1681 bool "none (WARNING - BUFSIZ will be 256 in stdio.h)"
1682 depends on !UCLIBC_HAS_WCHAR
1684 config UCLIBC_HAS_STDIO_BUFSIZ_256
1685 bool "256 (minimum ANSI/ISO C99 value)"
1687 config UCLIBC_HAS_STDIO_BUFSIZ_512
1690 config UCLIBC_HAS_STDIO_BUFSIZ_1024
1693 config UCLIBC_HAS_STDIO_BUFSIZ_2048
1696 config UCLIBC_HAS_STDIO_BUFSIZ_4096
1699 config UCLIBC_HAS_STDIO_BUFSIZ_8192
1702 # If you add more choices, you will need to update uClibc_stdio.h.
1707 prompt "Stdio builtin buffer size (uClibc-specific)"
1708 depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
1709 default UCLIBC_HAS_STDIO_BUILTIN_BUFFER_NONE
1711 When a FILE is created with fopen(), an attempt is made to allocate
1712 a BUFSIZ buffer for it. If the allocation fails, fopen() will still
1713 succeed but the FILE will be unbuffered.
1715 This option adds a small amount of space to each FILE to act as an
1716 emergency buffer in the event of a buffer allocation failure.
1718 Most people will answer None.
1720 config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_NONE
1723 config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_4
1726 config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_8
1729 # If you add more choices, you will need to update uClibc_stdio.h.
1733 config UCLIBC_HAS_STDIO_SHUTDOWN_ON_ABORT
1734 bool "Attempt to shutdown stdio subsystem when abort() is called."
1736 ANSI/ISO C99 requires abort() to be asyn-signal-safe. So there was
1737 a behavioral change made in SUSv3. Previously, abort() was required
1738 to have the affect of fclose() on all open streams. The wording has
1739 been changed to "may" from "shall".
1741 Most people will answer N.
1743 config UCLIBC_HAS_STDIO_GETC_MACRO
1744 bool "Provide a macro version of getc()"
1745 depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
1748 Provide a macro version of getc().
1750 Most people will answer Y.
1752 config UCLIBC_HAS_STDIO_PUTC_MACRO
1753 bool "Provide a macro version of putc()"
1754 depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
1757 Provide a macro version of putc().
1759 Most people will answer Y.
1761 config UCLIBC_HAS_STDIO_AUTO_RW_TRANSITION
1762 bool "Support auto-r/w transition"
1765 Answer Y to enable the stdio subsystem to automaticly transition
1766 between reading and writing. This relaxes the ANSI/ISO C99
1769 When a file is opened with update mode ('+' as the second or third
1770 character in the list of mode argument values), both input and output
1771 may be performed on the associated stream. However, output shall not
1772 be directly followed by input without an intervening call to the
1773 fflush function or to a file positioning function (fseek, fsetpos,
1774 or rewind), and input shall not be directly followed by output without
1775 an intervening call to a file positioning function, unless the input
1776 operation encounters endÂofÂfile.
1778 Most people will answer Y.
1780 config UCLIBC_HAS_FOPEN_LARGEFILE_MODE
1781 bool "Support an fopen() 'F' flag for large file mode (uClibc-specific)"
1782 depends on UCLIBC_HAS_LFS
1784 Answer Y to enable a uClibc-specific extension to allow passing an
1785 additional 'F' flag in the mode string for fopen() to specify that
1786 the file should be open()ed with the O_LARGEFILE flag set.
1788 Most people will answer N.
1790 config UCLIBC_HAS_FOPEN_EXCLUSIVE_MODE
1791 bool "Support an fopen() 'x' flag for exclusive mode (glibc-compat)"
1793 Answer Y to support a glibc extension to allow passing
1794 additional 'x' flag in the mode string for fopen() to specify that
1795 the file should be open()ed with the O_EXCL flag set.
1797 Most people will answer N.
1799 config UCLIBC_HAS_FOPEN_CLOSEEXEC_MODE
1800 bool "Support an fopen() 'e' flag for close-on-exec mode (glibc-compat)"
1802 Answer Y to support a glibc extension to allow passing
1803 additional 'e' flag in the mode string for fopen() to specify that
1804 the file should be open()ed with the O_CLOEXEC flag set.
1806 Most people will answer N.
1808 config UCLIBC_HAS_GLIBC_CUSTOM_STREAMS
1809 bool "Support fmemopen(), open_memstream(), and fopencookie() (glibc-compat)"
1811 Answer Y to support the glibc 'custom stream' extension functions
1812 fmemopen(), open_memstream(), and fopencookie().
1814 NOTE: There are some minor differences regarding seeking behavior.
1816 Most people will answer N.
1818 config UCLIBC_HAS_PRINTF_M_SPEC
1819 bool "Support the '%m' specifier in printf format strings (glibc-compat)"
1821 Answer Y to support a glibc extension to interpret '%m' in printf
1822 format strings as an instruction to output the error message string
1823 (as generated by strerror) corresponding to the current value of
1826 Most people will answer N.
1828 config UCLIBC_HAS_ERRNO_MESSAGES
1829 bool "Include the errno message text in the library"
1832 Answer Y if you want to include the errno message text in the
1833 library. This adds about 3K to the library, but enables strerror()
1834 to generate text other than 'Unknown error <number>'.
1836 Most people will answer Y.
1838 config UCLIBC_HAS_SYS_ERRLIST
1839 bool "Support sys_errlist[] (obsolete-compat)"
1840 depends on UCLIBC_HAS_ERRNO_MESSAGES
1842 Answer Y if you want to support the obsolete sys_errlist[].
1843 This adds about 0.5k to the library, except for the mips
1844 arch where it adds over 4K.
1846 WARNING! In the future, support for sys_errlist[] may be unavailable
1847 in at least some configurations. In fact, it may be removed
1850 Most people will answer N.
1852 Application writers: use the strerror(3) function.
1854 config UCLIBC_HAS_SIGNUM_MESSAGES
1855 bool "Include the signum message text in the library"
1858 Answer Y if you want to include the signum message text in the
1859 library. This adds about 0.5K to the library, but enables strsignal()
1860 to generate text other than 'Unknown signal <number>'.
1862 Most people will answer Y.
1864 config UCLIBC_HAS_SYS_SIGLIST
1865 bool "Support sys_siglist[] (bsd-compat)"
1866 depends on UCLIBC_HAS_SIGNUM_MESSAGES
1868 Answer Y if you want to support sys_siglist[].
1870 WARNING! In the future, support for sys_siglist[] may be unavailable
1871 in at least some configurations. In fact, it may be removed
1874 Most people will answer N.
1876 config UCLIBC_HAS_GETTEXT_AWARENESS
1877 bool "Include gettext awareness"
1878 depends on UCLIBC_HAS_LOCALE && UCLIBC_MJN3_ONLY
1880 NOTE!!! Not yet integrated with strerror and strsignal. NOTE!!!
1882 Answer Y if you want to include weak stub gettext support and
1883 make the *strerror*() and strsignal() functions gettext-aware.
1885 Currently, to get functional gettext functionality you will need
1888 Most people will answer N.
1890 config UCLIBC_HAS_GNU_GETOPT
1891 bool "Support gnu getopt"
1894 Answer Y if you want to include full gnu getopt() instead of a
1895 (much smaller) SUSv3 compatible getopt().
1897 Most people will answer Y.
1899 config UCLIBC_HAS_GETOPT_LONG
1900 bool "Support getopt_long/getopt_long_only"
1901 depends on !UCLIBC_HAS_GNU_GETOPT
1904 Answer Y if you want to include getopt_long[_only() used by many
1907 Most people will answer Y.
1909 config UCLIBC_HAS_GNU_GETSUBOPT
1910 bool "Support glibc getsubopt"
1913 Answer Y if you want to include glibc getsubopt() instead of a
1914 smaller SUSv3 compatible getsubopt().
1916 Most people will answer Y.
1922 config UCLIBC_HAS_REGEX
1923 bool "Regular Expression Support"
1926 POSIX regular expression code is really big -- 53k all by itself.
1927 If you don't use regular expressions, turn this off and save space.
1928 Of course, if you only statically link, leave this on, since it will
1929 only be included in your apps if you use regular expressions.
1931 config UCLIBC_HAS_REGEX_OLD
1932 bool "Use the older (stable) regular expression code"
1933 depends on UCLIBC_HAS_REGEX
1936 There are two versions of regex. The older (stable) version has
1937 been in uClibc for quite a long time but hasn't seen too many
1938 updates. It also has some known issues when dealing with uncommon
1939 corner cases and multibyte/unicode strings. However, it is quite
1940 a bit smaller than the newer version.
1942 If the older version has worked for you and you don't need unicode
1943 support, then stick with the old version (and say Y here).
1944 Otherwise, you should use the new version (and say N here).
1946 config UCLIBC_HAS_FNMATCH
1947 bool "fnmatch Support"
1952 config UCLIBC_HAS_FNMATCH_OLD
1953 bool "Use the older (stable) fnmatch code"
1954 depends on UCLIBC_HAS_FNMATCH
1957 There are two versions of fnmatch. The older (stable) version has
1958 been in uClibc for quite a long time but hasn't seen too many
1959 updates. It also has some known issues when dealing with uncommon
1960 corner cases and multibyte/unicode strings. However, it is quite
1961 a bit smaller than the newer version.
1963 If the older version has worked for you and you don't need unicode
1964 support, then stick with the old version (and say Y here).
1965 Otherwise, you should use the new version (and say N here).
1967 config UCLIBC_HAS_WORDEXP
1968 bool "Support the wordexp() interface"
1969 depends on UCLIBC_HAS_GLOB
1971 The SuSv3 wordexp() interface performs word expansions per the Shell
1972 and Utilities volume of IEEE Std 1003.1-2001, Section 2.6. It is
1973 intended for use by applications that want to implement all of the
1974 standard Bourne shell expansions on input data.
1976 This interface is rarely used, and very large. Unless you have a
1977 pressing need for wordexp(), you should probably answer N.
1979 config UCLIBC_HAS_NFTW
1980 bool "Support the nftw() interface"
1982 The SuSv3 nftw() interface is used to recursively descend
1983 directory paths while repeatedly calling a function.
1985 This interface is rarely used, and adds around 4.5k. Unless you have
1986 a pressing need for nftw(), you should probably answer N.
1988 config UCLIBC_HAS_FTW
1989 bool "Support the ftw() interface (SUSv4-obsolete)"
1990 depends on UCLIBC_SUSV4_LEGACY
1992 The SuSv3 ftw() interface is used to recursively descend
1993 directory paths while repeatedly calling a function.
1995 This interface is rarely used, and adds around 4.5k. Unless you have
1996 a pressing need for ftw(), you should probably answer N.
1998 config UCLIBC_HAS_FTS
1999 bool "Support the fts() interface (bsd-compat)"
2001 The fts functions are provided for traversing UNIX file hierarchies.
2003 This interface is currently used by the elfutils and adds
2005 You should port your application to use the POSIX nftw()
2008 Unless you need to build/use elfutils, you should prolly answer N.
2010 config UCLIBC_HAS_GLOB
2011 bool "Support the glob() interface"
2012 depends on UCLIBC_HAS_FNMATCH
2016 The glob interface is somewhat large (weighing in at about 2,5k). It
2017 is used fairly often, but is an option since people wanting to go for
2018 absolute minimum size may wish to omit it.
2020 Most people will answer Y.
2022 config UCLIBC_HAS_GNU_GLOB
2023 bool "Support gnu glob() interface"
2024 depends on UCLIBC_HAS_GLOB
2026 The gnu glob interface is somewhat larger (weighing in at about 4,2k)
2027 than it's SuSv3 counterpart (and is out of date). It is an old copy
2028 from glibc and does not support all the GNU specific options.
2030 Answer Y if you want to include full gnu glob() instead of the smaller
2031 SUSv3 compatible glob().
2033 Most people will answer N.
2035 config UCLIBC_HAS_UTMPX
2036 bool "utmpx based support for tracking login/logouts to/from the system"
2038 Answer y to enable support for accessing user accounting database.
2039 It can be used to track all login/logout to the system.
2041 If unsure, just answer N.
2048 menu "Library Installation Options"
2050 config RUNTIME_PREFIX
2051 string "uClibc runtime library directory"
2052 default "/usr/$(TARGET_ARCH)-linux-uclibc/"
2054 RUNTIME_PREFIX is the directory into which the uClibc runtime
2055 libraries will be installed. The result will look something
2058 lib/ <contains all runtime libraries>
2059 usr/bin/ldd <the ldd utility program>
2060 sbin/ldconfig <the ldconfig utility program>
2061 This value is used by the 'make install' Makefile target. Since this
2062 directory is compiled into the shared library loader, you will need to
2063 recompile uClibc if you change this value...
2065 For a typical target system this should be set to "/", such that
2066 'make install' will install /lib/libuClibc-<VERSION>.so
2069 string "uClibc development environment directory"
2070 default "/usr/$(TARGET_ARCH)-linux-uclibc/usr/"
2072 DEVEL_PREFIX is the directory into which the uClibc development
2073 environment will be installed. The result will look something
2076 lib/ <contains static libs>
2077 include/ <Where all the header files go>
2078 This value is used by the 'make install' Makefile target when
2079 installing a uClibc development environment.
2081 For a typical target system this should be set to "/usr", such that
2082 'make install' will install /usr/include/<header files>.
2085 string "library path component"
2088 Path component where libraries reside.
2090 For a typical target system this should be set to "lib", such that
2091 'make install' will install libraries to "/lib" and "/usr/lib"
2093 DEVEL_PREFIX/MULTILIB_DIR
2094 RUNTIME_PREFIX/MULTILIB_DIR
2096 Other settings may include "lib32" or "lib64".
2098 config HARDWIRED_ABSPATH
2099 bool "Hardwire absolute paths into linker scripts"
2102 This prepends absolute paths to the libraries mentioned in linker
2103 scripts such as libc.so.
2105 This is a build time optimization. It has no impact on dynamic
2106 linking at runtime, which doesn't use linker scripts.
2108 You must disable this to use uClibc with old non-sysroot toolchains,
2109 such as the prebuilt binary cross compilers at:
2110 http://uclibc.org/downloads/binaries
2112 The amount of time saved by this optimization is actually too small to
2113 measure. The linker just had to search the library path to find the
2114 linker script, so the dentries are cache hot if it has to search the
2115 same path again. But it's what glibc does, so we do it too.
2120 menu "Security options"
2122 config UCLIBC_BUILD_PIE
2123 bool "Build utilities as ET_DYN/PIE executables"
2124 depends on HAVE_SHARED
2125 depends on TARGET_arm || TARGET_frv || TARGET_i386 || TARGET_mips || TARGET_powerpc
2126 select FORCE_SHAREABLE_TEXT_SEGMENTS
2128 If you answer Y here, ldd and iconv are built as ET_DYN/PIE
2131 It requires gcc-3.4 and binutils-2.15 (for arm 2.16) or later.
2132 More about ET_DYN/PIE binaries on <http://pax.grsecurity.net/> .
2134 WARNING: This option also enables FORCE_SHAREABLE_TEXT_SEGMENTS, so
2135 all libraries have to be built with -fPIC or -fpic, and all
2136 assembler functions must be written as position independent
2139 config UCLIBC_HAS_ARC4RANDOM
2140 bool "Include the arc4random() function"
2142 Answer Y to support the OpenBSD-like arc4random() function. This
2143 function picks a random number between 0 and N, and will always return
2144 something even if the random driver is dead. If urandom fails then
2145 gettimeofday(2) will be used as the random seed. This function is
2146 designed to be more dependable than invoking /dev/urandom directly.
2147 OpenSSL and OpenNTPD currently support this function.
2149 Most people will answer N.
2151 config ARC4RANDOM_USES_NODEV
2152 bool "Do not use /dev/urandom with arc4random()"
2153 depends on UCLIBC_HAS_ARC4RANDOM
2155 Answer Y to use gettimeofday(2) and getpid(2) exclusively for
2156 arc4random(). This is not a bad idea for a diskless system, but
2157 it uses a lot of syscalls to stir each array element.
2159 Most people will answer N.
2164 config UCLIBC_HAS_SSP
2165 bool "Support for GCC stack smashing protector"
2166 depends on !HAVE_NO_SSP
2168 Add code to support GCC's -fstack-protector[-all] option to uClibc.
2169 This requires GCC 4.1 or newer. GCC does not have to provide libssp,
2170 the needed functions are added to ldso/libc instead.
2172 GCC's stack protector is a reimplementation of IBM's propolice.
2173 See http://www.trl.ibm.com/projects/security/ssp/ and
2174 http://www.linuxfromscratch.org/hints/downloads/files/ssp.txt
2177 Note that NOEXECSTACK on a kernel with address space randomization
2178 is generally sufficient to prevent most buffer overflow exploits
2179 without increasing code size. This option essentially adds debugging
2182 Most people will answer N.
2184 config UCLIBC_HAS_SSP_COMPAT
2185 bool "Support for gcc-3.x propolice smashing stack protector"
2186 depends on UCLIBC_HAS_SSP
2188 Add gcc-3.x propolice smashing stack protector to the library.
2190 This requires a patched version of GCC, supporting the
2191 -fstack-protector[-all] options, with the __guard and
2192 __stack_smash_handler functions removed from libgcc.
2193 These functions are added to ldso/libc instead.
2195 More information at:
2196 <http://www.research.ibm.com/trl/projects/security/ssp/>
2198 Most people will answer N.
2200 config SSP_QUICK_CANARY
2201 bool "Use simple guard values without accessing /dev/urandom"
2202 depends on UCLIBC_HAS_SSP
2204 Use gettimeofday(2) to define the __guard without accessing
2206 WARNING: This makes smashing stack protector vulnerable to timing
2208 Most people will answer N.
2211 prompt "Propolice protection blocking signal"
2212 depends on UCLIBC_HAS_SSP
2214 default PROPOLICE_BLOCK_SEGV
2216 "abort" use SIGABRT to block offending programs.
2217 This is the default implementation.
2219 "segfault" use SIGSEGV to block offending programs.
2220 Use this for debugging.
2222 If unsure, answer "abort".
2224 config PROPOLICE_BLOCK_ABRT
2227 config PROPOLICE_BLOCK_SEGV
2232 config UCLIBC_BUILD_SSP
2233 bool "Build uClibc with -fstack-protector"
2234 depends on UCLIBC_HAS_SSP
2236 Build all uClibc libraries and executables with -fstack-protector,
2237 adding extra stack overflow checking to most uClibc functions.
2239 config UCLIBC_BUILD_RELRO
2240 bool "Build uClibc with linker option -z RELRO"
2241 depends on HAVE_SHARED
2244 Build all libraries and executables with "ld -z relro".
2246 This tells the linker to mark chunks of an executable or shared
2247 library read-only after applying dynamic relocations. (This comes
2248 up when a global const variable is initialized to the address of a
2249 function or the value of another global variable.)
2251 This is a fairly obscure option the ld man page doesn't even bother
2252 to document properly. It's a security paranoia issue that's more
2253 likely to consume memory (by allocating an extra page) rather than
2256 This is explained in more depth at
2257 http://www.airs.com/blog/archives/189
2259 Nobody is likely to care whether you say Y or N here.
2261 config UCLIBC_BUILD_NOW
2262 bool "Build uClibc with linker option -z NOW"
2263 depends on HAVE_SHARED
2265 Build all libraries and executables with "ld -z now".
2267 This tells the linker to resolve all symbols when the library is
2268 first loaded, rather than when each function is first called. This
2269 increases start-up latency by a few microseconds and may do
2270 unnecessary work (resolving symbols that are never used), but the
2271 realtime people like it for making microbenchmark timings slightly
2272 more predictable and in some cases it can be slightly faster due to
2273 CPU cache behavior (not having to fault the linker back in to do
2274 lazy symbol resolution).
2276 Most people can't tell the difference between selecting Y or N here.
2278 config UCLIBC_BUILD_NOEXECSTACK
2279 bool "Build uClibc with noexecstack marking"
2282 Mark all assembler files as noexecstack, which will mark uClibc
2283 as not requiring an executable stack. (This doesn't prevent other
2284 files you link against from claiming to need an executable stack, it
2285 just won't cause uClibc to request it unnecessarily.)
2287 This is a security thing to make buffer overflows harder to exploit.
2288 By itself, it's kind of useless, as Linus Torvalds explained in 1998:
2289 http://old.lwn.net/1998/0806/a/linus-noexec.html
2291 It only actually provides any security when combined with address
2292 space randomization, explained here: http://lwn.net/Articles/121845/
2294 Address space randomization is on by default in current linux
2295 kernels (although it can be disabled using the option
2298 You should probably say Y.
2302 menu "Development/debugging options"
2304 config CROSS_COMPILER_PREFIX
2305 string "Cross-compiling toolchain prefix"
2308 The prefix used to execute your cross-compiling toolchain. For
2309 example, if you run 'arm-linux-uclibc-gcc' to compile something,
2310 then enter 'arm-linux-uclibc-' here.
2312 config UCLIBC_EXTRA_CFLAGS
2313 string "Extra CFLAGS"
2316 Add any additional CFLAGS to be used to build uClibc.
2319 bool "Enable debugging symbols"
2320 select EXTRA_WARNINGS
2322 Say Y here if you wish to compile uClibc with debugging symbols.
2323 This will allow you to use a debugger to examine uClibc internals
2324 while applications are running. This increases the size of the
2325 library considerably and should only be used when doing development.
2326 If you are doing development and want to debug uClibc, answer Y.
2328 Otherwise, answer N.
2331 bool "Build pthread with debugging output"
2332 depends on UCLIBC_HAS_THREADS && LINUXTHREADS_OLD
2334 Enable debug output in libpthread. This is only useful when doing
2335 development in libpthread itself.
2337 Otherwise, answer N.
2340 bool "Strip libraries and executables"
2344 Say Y here if you do wish to strip all uClibc libraries and
2345 executables. No stripping increases the size of the binaries
2346 considerably, but makes it possible to debug uClibc libraries.
2347 Most people will answer Y.
2350 bool "Build with run-time assertion testing"
2352 Say Y here to include runtime assertion tests.
2353 This enables runtime assertion testing in some code, which can
2354 increase the size of the library and incur runtime overhead.
2355 If you say N, then this testing will be disabled.
2357 config SUPPORT_LD_DEBUG
2358 bool "Build the shared library loader with debugging support"
2359 depends on HAVE_SHARED
2361 Answer Y here to enable all the extra code needed to debug the uClibc
2362 native shared library loader. The level of debugging noise that is
2363 generated depends on the LD_DEBUG environment variable... Just set
2364 LD_DEBUG to something like: 'LD_DEBUG=token1,token2,.. prog' to
2365 debug your application. Diagnostic messages will then be printed to
2368 For now these debugging tokens are available:
2369 detail provide more information for some options
2370 move display copy processing
2371 symbols display symbol table processing
2372 reloc display relocation processing; detail shows the
2374 nofixups never fixes up jump relocations
2375 bindings displays the resolve processing (function calls);
2376 detail shows the relocation patch
2377 all Enable everything!
2379 The additional environment variable:
2380 LD_DEBUG_OUTPUT=file
2381 redirects the diagnostics to an output file created using
2382 the specified name and the process id as a suffix.
2384 An excellent start is simply:
2385 $ LD_DEBUG=binding,move,symbols,reloc,detail ./appname
2386 or to log everything to a file named 'logfile', try this
2387 $ LD_DEBUG=all LD_DEBUG_OUTPUT=logfile ./appname
2389 If you are doing development and want to debug uClibc's shared library
2390 loader, answer Y. Mere mortals answer N.
2392 config SUPPORT_LD_DEBUG_EARLY
2393 bool "Build the shared library loader with early debugging support"
2394 depends on HAVE_SHARED
2396 Answer Y here to if you find the uClibc shared library loader is
2397 crashing or otherwise not working very early on. This is typical
2398 only when starting a new port when you haven't figured out how to
2399 properly get the values for argc, argv, environ, etc. This method
2400 allows a degree of visibility into the very early shared library
2401 loader initialization process. If you are doing development and want
2402 to debug the uClibc shared library loader early initialization,
2403 answer Y. Mere mortals answer N.
2405 config UCLIBC_MALLOC_DEBUGGING
2406 bool "Build malloc with debugging support"
2407 depends on MALLOC || MALLOC_STANDARD
2410 Answer Y here to compile extra debugging support code into malloc.
2411 Malloc debugging output may then be enabled at runtime using the
2412 MALLOC_DEBUG environment variable.
2414 The value of MALLOC_DEBUG should be an integer, which is interpreted
2415 as a bitmask with the following bits:
2416 1 - do extra consistency checking
2417 2 - output messages for malloc/free calls and OS
2419 4 - output messages for the `MMB' layer
2420 8 - output messages for internal malloc heap manipulation
2423 Because this increases the size of malloc appreciably (due to strings
2424 etc), you should say N unless you need to debug a malloc problem.
2426 config UCLIBC_HAS_BACKTRACE
2427 bool "Add support for application self-debugging"
2428 depends on HAVE_SHARED
2430 Answer Y here to compile support for application self-debugging, by adding
2431 a new shared object "libubacktrace.so" that provides the following new
2433 backtrace, backtrace_symbols, backtrace_symbols_fd
2435 The backtrace functionality is currently supported on SH platform, and it
2436 based on dwarf2 informations to properly work, so any application that
2437 want to use backtrace needs to be built with -fexceptions flag.
2439 The symbol names may be unavailable without the use of special linker
2440 options. For systems using the GNU linker, it is necessary to use the
2441 -rdynamic linker option too. Note that names of "static" functions are not
2442 exposed, and won't be available in the backtrace.
2445 string "Compiler Warnings"
2448 Set this to the set of compiler warnings you wish to see while compiling.
2450 config EXTRA_WARNINGS
2451 bool "Enable extra annoying warnings"
2453 If you wish to build with extra warnings enabled, say Y here.
2456 bool "Compile all sources at once into an object"
2458 Set this to compile all sources at once into an object (IMA).
2459 This mode of compilation uses alot of memory but may produce
2462 Note that you need a very recent GCC for this to work, like
2463 gcc >= 4.3 plus eventually some patches.
2465 If unsure, keep the default of N.
2467 config UCLIBC_MJN3_ONLY
2468 bool "Manuel's hidden warnings"
2470 Answer Y here to see all Manuel's personal notes, warnings, and todos.
2472 Most people will answer N.
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