2 # For a description of the syntax of this configuration file,
3 # see extra/config/Kconfig-language.txt
6 mainmenu "uClibc-ng $VERSION C Library Configuration"
8 config DESIRED_TARGET_ARCH
17 prompt "Target Architecture"
18 default TARGET_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_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_nios2 if DESIRED_TARGET_ARCH = "nios2"
35 default TARGET_powerpc if DESIRED_TARGET_ARCH = "powerpc"
36 default TARGET_sh if DESIRED_TARGET_ARCH = "sh"
37 default TARGET_sparc if DESIRED_TARGET_ARCH = "sparc"
38 default TARGET_v850 if DESIRED_TARGET_ARCH = "v850"
39 default TARGET_x86_64 if DESIRED_TARGET_ARCH = "x86_64"
40 default TARGET_xtensa if DESIRED_TARGET_ARCH = "xtensa"
42 The architecture of your target.
59 # someone could sync this tree:
60 # http://linux-c6x.org/git/?p=uClibc.git;a=summary
91 config TARGET_microblaze
100 config TARGET_powerpc
121 menu "Target Architecture Features and Options"
124 source "extra/Configs/Config.alpha"
128 source "extra/Configs/Config.arm"
132 source "extra/Configs/Config.avr32"
136 source "extra/Configs/Config.bfin"
140 source "extra/Configs/Config.cris"
144 source "extra/Configs/Config.frv"
148 source "extra/Configs/Config.h8300"
152 source "extra/Configs/Config.hppa"
156 source "extra/Configs/Config.i386"
160 source "extra/Configs/Config.i960"
164 source "extra/Configs/Config.ia64"
168 source "extra/Configs/Config.m68k"
172 source "extra/Configs/Config.metag"
176 source "extra/Configs/Config.nios2"
180 source "extra/Configs/Config.microblaze"
184 source "extra/Configs/Config.mips"
188 source "extra/Configs/Config.powerpc"
192 source "extra/Configs/Config.sh"
196 source "extra/Configs/Config.sparc"
200 source "extra/Configs/Config.v850"
204 source "extra/Configs/Config.x86_64"
208 source "extra/Configs/Config.xtensa"
212 source "extra/Configs/Config.c6x"
216 source "extra/Configs/Config.arc"
219 config TARGET_SUBARCH
221 default "e500" if CONFIG_E500
222 default "classic" if CONFIG_CLASSIC
223 default "sh4" if CONFIG_SH4
224 default "" if CONFIG_386
225 default "i486" if CONFIG_486
226 default "i586" if CONFIG_586
227 default "i686" if CONFIG_686
228 default "arcv2" if CONFIG_ARC_CPU_HS
231 source "extra/Configs/Config.in.arch"
235 menu "General Library Settings"
241 bool "Generate only Position Independent Code (PIC)"
243 depends on !HAVE_NO_PIC
245 If you wish to build all of uClibc as PIC objects, then answer Y here.
246 If you are unsure, then you should answer N.
248 config ARCH_HAS_NO_SHARED
251 config ARCH_HAS_NO_LDSO
253 select ARCH_HAS_NO_SHARED
255 config ARCH_HAS_UCONTEXT
259 bool "Enable shared libraries"
260 depends on !ARCH_HAS_NO_SHARED
263 If you wish to build uClibc with support for shared libraries then
264 answer Y here. If you only want to build uClibc as a static library,
267 config FORCE_SHAREABLE_TEXT_SEGMENTS
268 bool "Only load shared libraries which can share their text segment"
269 depends on HAVE_SHARED
272 If you answer Y here, the uClibc native shared library loader will
273 only load shared libraries, which do not need to modify any
274 non-writable segments. These libraries haven't set the DT_TEXTREL
275 tag in the dynamic section (==> objdump).
276 All your libraries must be compiled with -fPIC or -fpic, and all
277 assembler function must be written as position independent code (PIC).
278 Enabling this option will make uClibc's shared library loader a
279 little bit smaller and guarantee that no memory will be wasted by
280 badly coded shared libraries.
282 config LDSO_LDD_SUPPORT
283 bool "Native 'ldd' support"
284 depends on HAVE_SHARED
287 Enable all the code needed to support traditional ldd,
288 which executes the shared library loader to resolve all dependencies
289 and then provide a list of shared libraries that are required for an
290 application to function. Disabling this option will make uClibc's
291 shared library loader a little bit smaller.
292 Most people will answer Y.
294 config LDSO_CACHE_SUPPORT
295 bool "Enable library loader cache (ld.so.conf)"
296 depends on HAVE_SHARED
299 Enable this to make use of /etc/ld.so.conf, the shared library loader
300 cache configuration file to support for non-standard library paths.
301 After updating this file, it is necessary to run 'ldconfig' to update
302 the /etc/ld.so.cache shared library loader cache file.
304 config LDSO_PRELOAD_ENV_SUPPORT
305 bool "Enable library loader LD_PRELOAD environment"
306 depends on HAVE_SHARED
309 Enable this to make use of LD_PRELOAD environment variable.
310 A whitespace-separated list of additional, user-specified, ELF shared
311 libraries to be loaded before all others. This can be used to
312 selectively override functions in other shared libraries. For
313 set-user-ID/set-group-ID ELF binaries, only libraries in the standard
314 search directories that are also set-user-ID will be loaded.
316 config LDSO_PRELOAD_FILE_SUPPORT
317 bool "Enable library loader preload file (ld.so.preload)"
318 depends on HAVE_SHARED
320 Enable this to make use of /etc/ld.so.preload. This file contains a
321 whitespace separated list of shared libraries to be loaded before
324 config LDSO_BASE_FILENAME
325 string "Shared library loader naming prefix"
326 depends on HAVE_SHARED && (LDSO_CACHE_SUPPORT || LDSO_PRELOAD_FILE_SUPPORT)
329 If you wish to support both uClibc and glibc on the same system, it
330 is necessary to set this to something other than "ld.so" to avoid
331 conflicts with glibc, which also uses "ld.so". This prevents both
332 libraries from using the same /etc/ld.so.* files. If you wish to
333 support both uClibc and glibc on the same system then you should set
334 this to "ld-uClibc.so".
336 Most people will leave this set to the default of "ld.so".
338 WARNING: Changing the default prefix could cause problems with
341 config LDSO_STANDALONE_SUPPORT
342 bool "Dynamic linker stand-alone mode support"
343 depends on HAVE_SHARED
345 The dynamic linker can be run either indirectly through running some
346 dynamically linked program or library (in which case no command line
347 options to the dynamic linker can be passed and, in the ELF case, the
348 dynamic linker which is stored in the .interp section of the program
349 is executed) or directly by running:
351 /lib/ld-uClibc.so.* [OPTIONS] [PROGRAM [ARGUMENTS]]
353 Stand-alone execution is a prerequisite for adding prelink
354 capabilities to uClibc dynamic linker, as well useful for testing an
355 updated version of the dynamic linker without breaking the system.
357 config LDSO_PRELINK_SUPPORT
358 bool "Dynamic linker prelink support"
359 depends on HAVE_SHARED
360 select LDSO_STANDALONE_SUPPORT
362 The dynamic linker can be used in stand-alone mode by the prelink tool
363 for prelinking ELF shared libraries and binaries to speed up startup
364 time. It also is able to load and handle prelinked libraries and
367 config UCLIBC_STATIC_LDCONFIG
368 bool "Link ldconfig statically"
369 depends on HAVE_SHARED
372 Enable this option to statically link the ldconfig binary.
374 Making ldconfig static can be beneficial if you have a library
375 problem and need to use ldconfig to recover. Sometimes it is
376 preferable to instead keep the size of the system down, in which
377 case you should disable this option.
380 bool "Enable ELF RUNPATH tag support"
381 depends on HAVE_SHARED
382 default y if LDSO_CACHE_SUPPORT
384 ELF's may have dynamic RPATH/RUNPATH tags. These tags list paths
385 which extend the library search paths. They are really only useful
386 if a package installs libraries in non standard locations and
387 ld.so.conf support is disabled.
389 Usage of RUNPATH tags is not too common, so disabling this feature
390 should be safe for most people.
392 config LDSO_RUNPATH_OF_EXECUTABLE
393 bool "Use executables RUNPATH/RPATH when searching for libraries."
394 depends on LDSO_RUNPATH
397 Use the executables RUNPATH/RPATH to find to find libraries even
398 though this behavour is not standard. Setting this option causes
399 the uclibc dynamic linker behavour to match the glibc dynamic linker.
401 config LDSO_SAFE_RUNPATH
402 bool "Allow only RUNPATH beginning with /"
403 depends on LDSO_RUNPATH
406 Allow only absolute path in RPATH/RUNPATH.
408 config LDSO_SEARCH_INTERP_PATH
409 bool "Add ldso path to lib search path"
410 depends on HAVE_SHARED
413 The ldso is told where it is being executed from and can use that
414 path to find related core libraries. This is useful by default,
415 but can be annoying in a mixed development environment.
417 i.e. if the ldso is run from /foo/boo/ldso.so, it will start its
418 library search with /foo/boo/
420 If unsure, simply say Y here.
422 config LDSO_LD_LIBRARY_PATH
423 bool "Add LD_LIBRARY_PATH to lib search path"
424 depends on HAVE_SHARED
427 On hardened system it could be useful to disable the use of
428 LD_LIBRARY_PATH environment variable (a colon-separated list of
429 directories in which to search for ELF libraries at execution-time).
431 If unsure, simply say Y here.
433 config LDSO_NO_CLEANUP
434 bool "Disable automatic unloading of dynamically loaded shared objects"
435 depends on HAVE_SHARED
437 If you need complete allocation traces when debugging memory leaks
438 using Valgrind in a process that dynamically loads shared objects,
439 then answer Y here. Unlike glibc, uClibc unloads all dynamically
440 loaded shared objects when a process exits, which prevents Valgrind
441 from correctly resolving the symbols from the unloaded shared objects.
442 Unless you know you need this, you should answer N.
444 config UCLIBC_CTOR_DTOR
448 If you wish to build uClibc with support for global constructor
449 (ctor) and global destructor (dtor) support, then answer Y here.
450 When ctor/dtor support is enabled, binaries linked with uClibc must
451 also be linked with crtbegin.o and crtend.o which are provided by gcc
452 (the "*startfile:" and "*endfile:" settings in your gcc specs file
453 may need to be adjusted to include these files). This support will
454 also add a small amount of additional size to each binary compiled vs
455 uClibc. If you will be using uClibc with C++, or if you need the gcc
456 __attribute__((constructor)) and __attribute__((destructor)) to work,
457 then you definitely want to answer Y here. If you don't need ctors
458 or dtors and want your binaries to be as small as possible, then
461 config LDSO_GNU_HASH_SUPPORT
462 bool "Enable GNU hash style support"
463 depends on HAVE_SHARED
465 Newest binutils support a new hash style named GNU-hash. The dynamic
466 linker will use the new GNU-hash section (.gnu.hash) for symbol lookup
467 if present into the ELF binaries, otherwise it will use the old SysV
468 hash style (.hash). This ensures that it is completely backward
470 Further, being the hash table implementation self-contained into each
471 executable and shared libraries, objects with mixed hash style can
472 peacefully coexist in the same process.
474 If you want to use this new feature, answer Y
477 prompt "Thread support"
478 default HAS_NO_THREADS
480 If you want to compile uClibc with pthread support, then answer Y.
481 This will increase the size of uClibc by adding a bunch of locking
482 to critical data structures, and adding extra code to ensure that
483 functions are properly reentrant.
485 config HAS_NO_THREADS
488 Disable thread support.
490 config UCLIBC_HAS_LINUXTHREADS
491 bool "Enable support for linuxthreads"
492 # linuxthreads need nanosleep()
493 select UCLIBC_HAS_REALTIME
494 depends on !TARGET_arc && \
504 See here for information about linuxthreads:
505 http://en.wikipedia.org/wiki/LinuxThreads
507 config UCLIBC_HAS_THREADS_NATIVE
508 bool "Native POSIX Threading (NPTL)"
509 select UCLIBC_HAS_TLS
510 select UCLIBC_HAS_STDIO_FUTEXES
511 select UCLIBC_HAS_REALTIME
512 # i386 has no lowlevellock support (yet) as opposed to i486 onward
513 depends on !CONFIG_386 && \
522 !TARGET_microblaze && \
525 If you want to compile uClibc with NPTL support, then answer Y.
529 config UCLIBC_HAS_THREADS
530 def_bool y if !HAS_NO_THREADS
532 config UCLIBC_HAS_TLS
533 bool "Thread-Local Storage"
534 depends on UCLIBC_HAS_THREADS_NATIVE
536 If you want to enable TLS support then answer Y.
537 This is fast an efficient way to store per-thread local data
538 which is not on stack. It needs __thread support enabled in
541 config PTHREADS_DEBUG_SUPPORT
542 bool "Build pthreads debugging support"
543 depends on UCLIBC_HAS_THREADS
545 Say Y here if you wish to be able to debug applications that use
546 uClibc's pthreads library. By enabling this option, a library
547 named libthread_db will be built. This library will be dlopen()'d
548 by gdb and will allow gdb to debug the threads in your application.
550 IMPORTANT NOTE! Because gdb must dlopen() the libthread_db library,
551 you must compile gdb with uClibc in order for pthread debugging to
554 If you are doing development and want to debug applications using
555 uClibc's pthread library, answer Y. Otherwise, answer N.
557 config UCLIBC_HAS_SYSLOG
558 bool "Syslog support"
560 depends on UCLIBC_HAS_NETWORK_SUPPORT
561 select UCLIBC_HAS_SOCKET
563 Support sending messages to the system logger.
564 This requires socket-support.
566 config UCLIBC_HAS_LFS
567 bool "Large File Support"
570 If you wish to build uClibc with support for accessing large files
571 (i.e. files greater then 2 GiB) then answer Y. Do not enable this
572 if you are using an older Linux kernel (2.0.x) that lacks large file
573 support. Enabling this option will increase the size of uClibc.
576 prompt "Malloc Implementation"
577 default MALLOC if ! ARCH_USE_MMU
578 default MALLOC_STANDARD if ARCH_USE_MMU
583 "malloc" use mmap for all allocations and so works very well on
584 MMU-less systems that do not support the brk() system call. It is
585 pretty smart about reusing already allocated memory, and minimizing
587 This is the default for uClinux MMU-less systems.
592 "malloc-simple" is trivially simple and slow as molasses. It
593 was written from scratch for uClibc, and is the simplest possible
594 (and therefore smallest) malloc implementation.
596 This uses only the mmap() system call to allocate and free memory,
597 and does not use the brk() system call at all, making it a fine
598 choice for MMU-less systems with very limited memory. It's 100%
599 standards compliant, thread safe, very small, and releases freed
600 memory back to the OS immediately rather than keeping it in the
601 process's heap for reallocation. It is also VERY SLOW.
603 config MALLOC_STANDARD
604 bool "malloc-standard"
605 depends on ARCH_USE_MMU
607 "malloc-standard" is derived from the public domain dlmalloc
608 implementation by Doug Lea. It is quite fast, and is pretty smart
609 about reusing already allocated memory, and minimizing memory
610 wastage. This uses brk() for small allocations, while using mmap()
611 for larger allocations. This is the default malloc implementation
614 If unsure, answer "malloc-standard".
618 config MALLOC_GLIBC_COMPAT
619 bool "Malloc returns live pointer for malloc(0)"
621 The behavior of malloc(0) is listed as implementation-defined by
622 SuSv3. Glibc returns a valid pointer to something, while uClibc
623 normally returns NULL. I personally feel glibc's behavior is
624 not particularly safe, and allows buggy applications to hide very
627 When this option is enabled, uClibc will act just like glibc, and
628 return a live pointer when someone calls malloc(0). This pointer
629 provides a malloc'ed area with a size of 1 byte. This feature is
630 mostly useful when dealing with applications using autoconf's broken
631 AC_FUNC_MALLOC macro (which redefines malloc as rpl_malloc if it
632 does not detect glibc style returning-a-valid-pointer-for-malloc(0)
633 behavior). Most people can safely answer N.
635 config UCLIBC_HAS_OBSTACK
636 bool "Obstack Support (gnu extension)"
638 When this option is enabled, uClibc will provide support for obstacks.
639 An obstack is a structure in which memory can be dynamically allocated
640 as a 'stack of objects'. Many programs need this GNU extention and
641 you should say Y if you are using any. Otherwise, say N to save some
644 config UCLIBC_DYNAMIC_ATEXIT
645 bool "Dynamic atexit() Support"
648 When this option is enabled, uClibc will support an infinite number,
649 of atexit() and on_exit() functions, limited only by your available
650 memory. This can be important when uClibc is used with C++, since
651 global destructors are implemented via atexit(), and it is quite
652 possible to exceed the default number when this option is disabled.
653 Enabling this option adds a few bytes, and more significantly makes
654 atexit and on_exit depend on malloc, which can be bad when compiling
657 Unless you use uClibc with C++, you should probably answer N.
660 bool "Old (visible) atexit Support"
662 Enable this option if you want to update from 0.9.28 to git/0.9.29,
663 else you will be missing atexit() until you rebuild all apps.
665 config UCLIBC_HAS_UTMPX
666 bool "utmpx based support for tracking login/logouts to/from the system"
668 Answer y to enable support for accessing user accounting database.
669 It can be used to track all login/logout to the system.
671 config UCLIBC_HAS_UTMP
672 bool "utmp support (XPG2 compat, SVr4 compat)"
673 depends on UCLIBC_HAS_UTMPX
675 Answer y to enable legacy SVID support for accessing
676 user accounting database:
677 getutent(), getutid(), getutline(), pututline(),
678 setutent(), endutent(), utmpname() in utmp.h
679 It can be used to track all login/logout to the system.
681 If unsure, answer N and use corresponding POSIX functions
684 config UCLIBC_SUSV2_LEGACY
685 bool "Enable SuSv2 LEGACY functions"
687 Enable this option if you want to have SuSv2 LEGACY functions
688 Currently applies to:
692 WARNING! ABI incompatibility.
694 config UCLIBC_SUSV3_LEGACY
695 bool "Enable SuSv3 LEGACY functions"
701 Enable this option if you want to have SuSv3 LEGACY functions
702 in the library, else they are replaced by SuSv3 proposed macros.
703 Currently applies to:
705 bcmp, bcopy, bzero, index, rindex, ftime,
706 bsd_signal, (ecvt), (fcvt), gcvt, (getcontext),
707 (getwd), (makecontext),
708 mktemp, (pthread_attr_getstackaddr), (pthread_attr_setstackaddr),
709 scalb, (setcontext), (swapcontext), ualarm, usleep,
712 WARNING! ABI incompatibility.
714 config UCLIBC_HAS_CONTEXT_FUNCS
715 bool "Use obsolescent context control functions"
716 depends on UCLIBC_SUSV3_LEGACY && ARCH_HAS_UCONTEXT
718 Add into library the SuSv3 obsolescent functions used for context
719 control. The setcontext family allows the implementation in C of
720 advanced control flow patterns such as iterators, fibers, and
721 coroutines. They may be viewed as an advanced version of
722 setjmp/longjmp; whereas the latter allows only a single non-local jump
723 up the stack, setcontext allows the creation of multiple cooperative
724 threads of control, each with its own stack.
725 These functions are: setcontext, getcontext, makecontext, swapcontext.
727 config UCLIBC_SUSV3_LEGACY_MACROS
728 bool "Enable SuSv3 LEGACY macros"
730 Enable this option if you want to have SuSv3 LEGACY macros.
731 Currently applies to bcopy/bzero/bcmp/index/rindex et al.
732 WARNING! ABI incompatibility.
734 config UCLIBC_SUSV4_LEGACY
735 bool "Enable SuSv4 LEGACY or obsolescent functions"
737 Enable this option if you want to have SuSv4 LEGACY functions
738 and macros in the library.
739 Currently applies to:
742 _longjmp, _setjmp, _tolower, _toupper, ftw, getitimer,
743 gettimeofday, isascii, pthread_getconcurrency,
744 pthread_setconcurrency, setitimer, setpgrp, sighold,
745 sigignore, sigpause, sigrelse, sigset, siginterrupt,
746 tempnam, toascii, ulimit.
749 asctime, asctime_r, ctime, ctime_r, gets, rand_r,
752 WARNING! ABI incompatibility.
754 config UCLIBC_STRICT_HEADERS
755 bool "Hide structures and constants for unsupported features"
757 Hide structures and constants in headers that should not be used,
758 because the respective feature is disabled.
760 WARNING! enabling this option requires to patch many faulty apps,
761 since they make (wrongly) use of these structures/constants,
762 although the feature was disabled.
764 config UCLIBC_HAS_STUBS
765 bool "Provide stubs for unavailable functionality"
767 With this option uClibc provides non-functional stubs for
768 functions which are impossible to implement on the target
769 architecture. Otherwise, such functions are simply omitted.
771 config UCLIBC_HAS_SHADOW
772 bool "Shadow Password Support"
775 Answer N if you do not need shadow password support.
776 Most people will answer Y.
778 config UCLIBC_HAS_PROGRAM_INVOCATION_NAME
779 bool "Support for program_invocation_name"
781 Support for the GNU-specific program_invocation_name and
782 program_invocation_short_name strings. Some GNU packages
783 (like tar and coreutils) utilize these for extra useful
784 output, but in general are not required.
786 At startup, these external strings are automatically set
787 up based on the value of ARGV[0].
789 If unsure, just answer N.
791 config UCLIBC_HAS___PROGNAME
792 bool "Support for __progname"
795 Some packages (like openssh) like to peek into internal libc
796 symbols to make their output a bit more user friendly.
798 At startup, __progname is automatically set up based on the
801 If unsure, just answer N.
803 config UCLIBC_HAS_PTY
804 bool "Support for pseudo-terminals"
807 This enables support for pseudo-terminals (see man 4 pts
810 If unsure, just answer Y.
813 bool "Assume that /dev/pts is a devpts or devfs file system"
815 depends on UCLIBC_HAS_PTY
817 Enable this if /dev/pts is on a devpts or devfs filesystem. Both
818 these filesystems automatically manage permissions on the /dev/pts
819 devices. You may need to mount your devpts or devfs filesystem on
820 /dev/pts for this to work.
822 Most people should answer Y.
824 config UNIX98PTY_ONLY
825 bool "Support only Unix 98 PTYs"
827 depends on UCLIBC_HAS_PTY
829 If you want to support only Unix 98 PTYs enable this. Some older
830 applications may need this disabled and will thus use legacy BSD
831 style PTY handling which is more complex and also bigger than
832 Unix 98 PTY handling.
834 For most current programs, you can generally answer Y.
837 config UCLIBC_HAS_GETPT
838 bool "Support getpt() (glibc-compat)"
839 depends on UCLIBC_HAS_PTY
841 Some packages may need getpt().
842 All of those are non-standard and can be considered
843 GNU/libc compatibility.
844 Either use posix_openpt() or just open /dev/ptmx yourself.
846 If unsure, just say N.
850 # Have to use __libc_ptyname{1,2}[] and related bloat
851 config UCLIBC_HAS_GETPT
855 config UCLIBC_HAS_LIBUTIL
856 bool "Provide libutil library and functions"
857 depends on UCLIBC_HAS_PTY
859 Provide a libutil library.
860 This non-standard conforming library provides the following
863 forkpty(): combines openpty(), fork(2), and login_tty() to
864 create a new process operating in a pseudo-terminal.
865 login(): write utmp and wtmp entries
866 login_tty(): prepares for a login on the tty fd by creating a
867 new session, making fd the controlling terminal for
868 the calling process, setting fd to be the standard
869 input, output, and error streams of the current
870 process, and closing fd.
871 logout(): write utmp and wtmp entries
872 logwtmp(): constructs a utmp structure and calls updwtmp() to
873 append the structure to the utmp file.
874 openpty(): finds an available pseudo-terminal and returns
875 file descriptors for the master and slave
877 This library adds about 3k-4k to your system.
879 config UCLIBC_HAS_TM_EXTENSIONS
880 bool "Support 'struct tm' timezone extension fields"
883 Enabling this option adds fields to 'struct tm' in time.h for
884 tracking the number of seconds east of UTC, and an abbreviation for
885 the current timezone. These fields are not specified by the SuSv3
886 standard, but they are commonly used in both GNU and BSD application
889 To strictly follow the SuSv3 standard, leave this disabled.
890 Most people will probably want to answer Y.
892 config UCLIBC_HAS_TZ_CACHING
893 bool "Enable caching of the last valid timezone 'TZ' string"
896 Answer Y to enable caching of the last valid 'TZ' string describing
897 the timezone setting. This allows a quick string compare to avoid
898 repeated parsing of unchanged 'TZ' strings when tzset() is called.
900 Most people will answer Y.
902 config UCLIBC_HAS_TZ_FILE
903 bool "Enable '/etc/TZ' file support to set a default timezone (uClibc-specific)"
906 Answer Y to enable the setting of a default timezone for uClibc.
908 Ordinarily, uClibc gets the timezone information exclusively from the
909 'TZ' environment variable. In particular, there is no support for
910 the zoneinfo directory tree or the /etc/timezone file used by glibc.
912 With this option enabled, uClibc will use the value stored in the
913 file '/etc/TZ' (default path) to obtain timezone information if the
914 'TZ' environment variable is missing or has an invalid value. The
915 file consists of a single line (newline required) of text describing
916 the timezone in the format specified for the TZ environment variable.
918 Doing 'echo CST6CDT > /etc/TZ' is enough to create a valid file.
920 http://www.opengroup.org/onlinepubs/007904975/basedefs/xbd_chap08.html
921 for details on valid settings of 'TZ'.
923 Most people will answer Y.
925 config UCLIBC_HAS_TZ_FILE_READ_MANY
926 bool "Repeatedly read the '/etc/TZ' file"
927 depends on UCLIBC_HAS_TZ_FILE
930 Answer Y to enable repeated reading of the '/etc/TZ' file even after
931 a valid value has been read. This incurs the overhead of an
932 open/read/close for each tzset() call (explicit or implied). However,
933 setting this will allow applications to update their timezone
934 information if the contents of the file change.
936 Most people will answer Y.
938 config UCLIBC_TZ_FILE_PATH
939 string "Path to the 'TZ' file for setting the global timezone"
940 depends on UCLIBC_HAS_TZ_FILE
943 This is the path to the 'TZ' file.
945 Most people will use the default of '/etc/TZ'.
947 config UCLIBC_FALLBACK_TO_ETC_LOCALTIME
948 bool "Use /etc/localtime as a fallback"
949 depends on UCLIBC_HAS_TZ_FILE
952 Answer Y to try to use /etc/localtime file.
953 On glibc systems this file (if it is in TZif2 format)
954 contains timezone string at the end.
956 Most people will answer Y.
960 menu "Advanced Library Settings"
962 config UCLIBC_PWD_BUFFER_SIZE
963 int "Buffer size for getpwnam() and friends"
967 This sets the value of the buffer size for getpwnam() and friends.
968 By default, this is 256. (For reference, glibc uses 1024).
969 The value can be found using sysconf() with the _SC_GETPW_R_SIZE_MAX
972 config UCLIBC_GRP_BUFFER_SIZE
973 int "Buffer size for getgrnam() and friends"
977 This sets the value of the buffer size for getgrnam() and friends.
978 By default, this is 256. (For reference, glibc uses 1024).
979 The value can be found using sysconf() with the _SC_GETGR_R_SIZE_MAX
982 comment "Support various families of functions"
984 config UCLIBC_LINUX_MODULE_26
985 bool "Linux kernel module functions (2.6)"
988 delete_module, init_module
989 are used in linux for loadable kernel modules.
991 Say N if you do not use kernel modules.
993 config UCLIBC_LINUX_MODULE_24
994 bool "Linux kernel module functions (<2.6)"
995 depends on !TARGET_bfin && !TARGET_c6x
997 create_module, query_module
998 are used in linux (prior to 2.6) for loadable kernel modules.
1000 Say N if you do not use kernel modules, or you only support
1003 config UCLIBC_LINUX_SPECIFIC
1004 bool "Linux specific functions"
1007 accept4(), bdflush(),
1008 capget(), capset(), eventfd(), fallocate(),
1009 fstatfs(), getrandom(), inotify_*(), ioperm(), iopl(),
1010 madvise(), modify_ldt(), pipe2(), personality(),
1011 prctl()/arch_prctl(), pivot_root(), modify_ldt(),
1012 ppoll(), readahead(), reboot(), remap_file_pages(),
1013 sched_getaffinity(), sched_setaffinity(), sendfile(),
1014 setfsgid(), setfsuid(), setresgid(), setresuid(),
1015 splice(), vmsplice(), tee(), signalfd(), statfs(),
1016 swapoff(), swapon(), sync_file_range(), _sysctl(),
1017 sysinfo(), timerfd_*(), vhangup(), umount(), umount2()
1019 config UCLIBC_HAS_GNU_ERROR
1020 bool "Support GNU extensions for error-reporting"
1023 Support for the GNU-specific error(), error_at_line(),
1024 void (* error_print_progname)(), error_message_count
1025 functions and variables. Some GNU packages
1026 utilize these for extra useful output, but in general
1029 If unsure, just answer N.
1031 config UCLIBC_BSD_SPECIFIC
1032 bool "BSD specific functions"
1035 mincore(), getdomainname(), setdomainname()
1039 config UCLIBC_HAS_BSD_ERR
1040 bool "BSD err functions"
1043 These functions are non-standard BSD extensions.
1044 err(), errx(), warn(), warnx(), verr(), verrx(), vwarn(), vwarnx()
1048 config UCLIBC_HAS_OBSOLETE_BSD_SIGNAL
1049 bool "BSD obsolete signal functions"
1051 These functions are provided as a compatibility interface for
1052 programs that make use of the historical System V signal API.
1053 This API is obsolete:
1054 new applications should use the POSIX signal API (sigaction(2),
1055 sigprocmask(2), etc.).
1058 sigset(), sighold(), sigrelse(), sigignore()
1062 config UCLIBC_HAS_OBSOLETE_SYSV_SIGNAL
1063 bool "SYSV obsolete signal functions"
1065 Use of sysv_signal() should be avoided; use sigaction(2) instead.
1069 config UCLIBC_NTP_LEGACY
1070 bool "ntp_*() aliases"
1072 Provide legacy aliases for ntp functions:
1073 ntp_adjtime(), ntp_gettime()
1075 It is safe to say N here.
1077 config UCLIBC_SV4_DEPRECATED
1078 bool "Enable SVr4 deprecated functions"
1080 These functions are DEPRECATED in System V release 4.
1081 Say N unless you desparately need one of the functions below:
1083 ustat() [use statfs(2) in your code instead]
1085 config UCLIBC_HAS_REALTIME
1086 bool "Realtime-related family of SUSv functions"
1089 These functions are part of the Timers option and need not
1090 be available on all implementations.
1091 Includes AIO, message-queue, scheduler, semaphore functions:
1106 clock_getres(), clock_gettime(), clock_settime()
1108 mlockall(), munlockall()
1120 sched_get_priority_max(), sched_get_priority_min()
1121 sched_getscheduler()
1122 sched_rr_get_interval()
1124 sched_setscheduler()
1131 sem_trywait(), sem_wait()
1134 sigtimedwait(), sigwaitinfo()
1137 timer_getoverrun(), timer_gettime(), timer_settime()
1139 config UCLIBC_HAS_ADVANCED_REALTIME
1140 bool "Advanced realtime-related family of SUSv functions"
1142 depends on UCLIBC_HAS_REALTIME
1144 These functions are part of the Timers option and need not
1145 be available on all implementations.
1147 clock_getcpuclockid()
1156 posix_spawnattr_destroy(), posix_spawnattr_init()
1157 posix_spawnattr_getflags(), posix_spawnattr_setflags()
1158 posix_spawnattr_getpgroup(), posix_spawnattr_setpgroup()
1159 posix_spawnattr_getschedparam(), posix_spawnattr_setschedparam()
1160 posix_spawnattr_getschedpolicy(), posix_spawnattr_setschedpolicy()
1161 posix_spawnattr_getsigdefault(), posix_spawnattr_setsigdefault()
1162 posix_spawnattr_getsigmask(), posix_spawnattr_setsigmask()
1163 posix_spawn_file_actions_addclose()
1164 posix_spawn_file_actions_adddup2()
1165 posix_spawn_file_actions_addopen()
1166 posix_spawn_file_actions_destroy()
1167 posix_spawn_file_actions_init()
1170 posix_typed_mem_get_info()
1171 pthread_mutex_timedlock()
1174 #config UCLIBC_HAS_TERMIOS
1175 # bool "termios functions"
1178 # Get and set terminal attributes, line control, get and set baud
1180 # termios(), tcgetattr(), tcsetattr(), tcsendbreak(), tcdrain(),
1181 # tcflush(), tcflow(), cfmakeraw(), cfgetospeed(), cfgetispeed(),
1182 # cfsetispeed(), cfsetospeed(), cfsetspeed()
1186 config UCLIBC_HAS_EPOLL
1190 epoll_create(), epoll_ctl(), epoll_wait() functions.
1192 config UCLIBC_HAS_XATTR
1193 bool "Extended Attributes"
1196 Extended Attributes support.
1211 Say N unless you need support for extended attributes and the
1212 filesystems do actually support them.
1214 config UCLIBC_HAS_PROFILING
1215 bool "Profiling support"
1218 gcc's -finstrument-functions needs these.
1220 Most people can safely answer N.
1222 config UCLIBC_HAS_CRYPT_IMPL
1223 bool "libcrypt support"
1226 libcrypt contains crypt(), setkey() and encrypt()
1228 config UCLIBC_HAS_SHA256_CRYPT_IMPL
1229 bool "libcrypt SHA256 support"
1230 depends on UCLIBC_HAS_CRYPT_IMPL
1232 This adds support for SHA256 password hashing via the crypt() function.
1233 Say N here if you do not need SHA256 crypt support.
1235 config UCLIBC_HAS_SHA512_CRYPT_IMPL
1236 bool "libcrypt SHA512 support"
1237 depends on UCLIBC_HAS_CRYPT_IMPL
1239 This adds support for SHA512 password hashing via the crypt() function.
1240 Say N here if you do not need SHA512 crypt support.
1242 config UCLIBC_HAS_CRYPT_STUB
1243 bool "libcrypt stubs"
1245 depends on !UCLIBC_HAS_CRYPT_IMPL
1247 Standards mandate that crypt(3) provides a stub if it is unavailable.
1248 If you enable this option then stubs for
1249 crypt(), setkey() and encrypt()
1250 will be provided in a small libcrypt.
1252 config UCLIBC_HAS_CRYPT
1254 depends on UCLIBC_HAS_CRYPT_IMPL || UCLIBC_HAS_CRYPT_STUB
1257 menuconfig UCLIBC_HAS_NETWORK_SUPPORT
1258 bool "Networking Support"
1261 Say N here if you do not need network support.
1263 if UCLIBC_HAS_NETWORK_SUPPORT
1264 config UCLIBC_HAS_SOCKET
1265 bool "Socket support"
1268 If you want to include support for sockets then answer Y.
1270 config UCLIBC_HAS_IPV4
1271 bool "IP version 4 support"
1273 select UCLIBC_HAS_SOCKET
1275 If you want to include support for the Internet Protocol
1276 (IP version 4) then answer Y.
1278 Most people will say Y.
1280 config UCLIBC_HAS_IPV6
1281 bool "IP version 6 support"
1282 select UCLIBC_HAS_SOCKET
1284 If you want to include support for the next version of the Internet
1285 Protocol (IP version 6) then answer Y.
1287 Most people should answer N.
1289 config UCLIBC_HAS_RPC
1290 bool "Remote Procedure Call (RPC) support"
1291 # RPC+socket-ipvX doesn't currently work.
1292 depends on UCLIBC_HAS_IPV4 || UCLIBC_HAS_IPV6
1294 If you want to include RPC support, enable this. RPC is rarely used
1295 for anything except for the NFS filesystem. Unless you plan to use
1296 NFS, you can probably leave this set to N and save some space.
1298 If you need to use NFS then you should answer Y.
1300 config UCLIBC_HAS_FULL_RPC
1301 bool "Full RPC support"
1302 depends on UCLIBC_HAS_RPC
1303 default y if !HAVE_SHARED
1305 Normally we enable just enough RPC support for things like rshd and
1306 nfs mounts to work. If you find you need the rest of the RPC stuff,
1307 then enable this option. Most people can safely answer N.
1309 config UCLIBC_HAS_REENTRANT_RPC
1310 bool "Reentrant RPC support"
1311 depends on UCLIBC_HAS_RPC
1312 default y if !HAVE_SHARED
1314 Most packages utilize the normal (non-reentrant) RPC functions, but
1315 some (like exportfs from nfs-utils) need these reentrant versions.
1317 Most people can safely answer N.
1319 config UCLIBC_USE_NETLINK
1320 bool "Use netlink to query interfaces"
1321 depends on UCLIBC_HAS_SOCKET
1323 In newer versions of Linux (2.4.17+), support was added for querying
1324 network device information via netlink rather than the old style
1325 ioctl's. Most of the time, the older ioctl style is sufficient (and
1326 it is smaller than netlink), but if you find that not all of your
1327 devices are being returned by the if_nameindex() function, you will
1328 have to use the netlink implementation.
1330 Most people can safely answer N.
1332 config UCLIBC_SUPPORT_AI_ADDRCONFIG
1333 bool "Support the AI_ADDRCONFIG flag"
1334 depends on UCLIBC_USE_NETLINK
1336 The implementation of AI_ADDRCONFIG is aligned with the glibc
1337 implementation using netlink to query interfaces to find both
1338 ipv4 and ipv6 support. This is only needed if an application uses
1339 the AI_ADDRCONFIG flag.
1341 Most people can safely answer N.
1343 config UCLIBC_HAS_BSD_RES_CLOSE
1344 bool "Support res_close() (bsd-compat)"
1346 Answer Y if you desperately want to support BSD compatibility in
1349 Most people will say N.
1351 config UCLIBC_HAS_COMPAT_RES_STATE
1352 bool "Use compatible but bloated _res"
1355 Answer Y if you build network utilities and they muck with resolver
1356 internals a lot (_res global structure). uclibc does not use most
1357 of _res.XXX fields, and with this option OFF they won't even exist.
1358 Which will make e.g. dig build fail.
1359 Answering N saves around 400 bytes in bss.
1361 config UCLIBC_HAS_EXTRA_COMPAT_RES_STATE
1362 bool "Use extra compatible but extra bloated _res"
1364 Answer Y if selecting UCLIBC_HAS_COMPAT_RES_STATE is not enough.
1365 As far as I can say, this should never be needed.
1367 config UCLIBC_HAS_RESOLVER_SUPPORT
1368 bool "DNS resolver functions"
1369 select UCLIBC_HAS_COMPAT_RES_STATE
1370 depends on UCLIBC_HAS_IPV4 || UCLIBC_HAS_IPV6
1372 Provide implementations for DNS resolver functions.
1373 In particular, the following functions will be added to the
1376 ns_skiprr, ns_initparse, ns_parserr, ns_msg_getflag,
1377 res_mkquery, res_init, res_ninit, res_close, res_nclose
1378 res_query, res_search, res_querydomain,
1380 ns_name_uncompress, ns_name_ntop, ns_name_pton, ns_name_unpack,
1381 ns_name_pack, ns_name_compress, ns_name_skip, dn_skipname,
1382 ns_get16, ns_get32, ns_put16, ns_put32
1384 config UCLIBC_HAS_LIBRESOLV_STUB
1385 bool "Provide libresolv stub"
1387 Provide a dummy resolv library.
1389 config UCLIBC_HAS_LIBNSL_STUB
1390 bool "Provide libnsl stub"
1392 Provide a dummy nsl library.
1397 menu "String and Stdio Support"
1399 config UCLIBC_HAS_STRING_GENERIC_OPT
1400 bool "Use faster (but larger) generic string functions"
1403 Answer Y to use the (tweaked) glibc generic string functions.
1405 In general, they are faster (but 3-5K larger) than the base
1406 uClibc string functions which are optimized solely for size.
1408 Many people will answer Y.
1410 config UCLIBC_HAS_STRING_ARCH_OPT
1411 bool "Use arch-specific assembly string functions (where available)"
1414 Answer Y to use any archtecture-specific assembly language string
1415 functions available for this target plaform.
1417 Note that assembly implementations are not available for all string
1418 functions, so some generic (written in C) string functions may
1421 These are small and fast, the only reason _not_ to say Y here is
1422 for debugging purposes.
1424 config UCLIBC_HAS_STDIO_FUTEXES
1425 bool "Use futexes for multithreaded I/O locking"
1426 depends on UCLIBC_HAS_THREADS_NATIVE
1428 If you want to compile uClibc to use futexes for low-level
1429 I/O locking, answer Y. Otherwise, answer N.
1431 config UCLIBC_HAS_CTYPE_TABLES
1432 bool "Use Table Versions Of 'ctype.h' Functions."
1435 Answer Y to use table versions of the 'ctype.h' functions.
1436 While the non-table versions are often smaller when building
1437 statically linked apps, they work only in stub locale mode.
1439 Most people will answer Y.
1441 config UCLIBC_HAS_CTYPE_SIGNED
1442 bool "Support Signed Characters In 'ctype.h' Functions."
1443 depends on UCLIBC_HAS_CTYPE_TABLES
1446 Answer Y to enable support for passing signed char values to
1447 the 'ctype.h' functions. ANSI/ISO C99 and SUSv3 specify that
1448 these functions are only defined for unsigned char values and
1449 EOF. However, glibc allows negative signed char values as well
1450 in order to support 'broken old programs'.
1452 Most people will answer Y.
1455 prompt "ctype argument checking"
1456 depends on UCLIBC_HAS_CTYPE_TABLES
1457 default UCLIBC_HAS_CTYPE_UNSAFE
1459 Please select the invalid arg behavior you want for the 'ctype'
1462 The 'ctype' functions are now implemented using table lookups, with
1463 the arg being the index. This can result in incorrect memory accesses
1464 or even segfaults for args outside of the allowed range.
1466 NOTE: This only affects the 'ctype' _functions_. It does not affect
1467 the macro implementations.
1469 config UCLIBC_HAS_CTYPE_UNSAFE
1470 bool "Do not check -- unsafe"
1472 config UCLIBC_HAS_CTYPE_CHECKED
1473 bool "Detect and handle appropriately"
1475 config UCLIBC_HAS_CTYPE_ENFORCED
1476 bool "Issue a diagnostic and abort()"
1481 config UCLIBC_HAS_WCHAR
1482 bool "Wide Character Support"
1484 Answer Y to enable wide character support. This will make uClibc
1485 much larger. It is also currently required for locale support.
1487 Most people will answer N.
1489 config UCLIBC_HAS_LOCALE
1490 bool "Locale Support"
1491 select UCLIBC_HAS_WCHAR
1492 select UCLIBC_HAS_CTYPE_TABLES
1494 uClibc now has full ANSI/ISO C99 locale support (except for
1495 wcsftime() and collating items in regex). Be aware that enabling
1496 this option will make uClibc much larger.
1498 Enabling UCLIBC_HAS_LOCALE with the default set of supported locales
1499 (169 UTF-8 locales, and 144 locales for other codesets) will enlarge
1500 uClibc by around 300k. You can reduce this size by building your own
1501 custom set of locate data (see extra/locale/LOCALES for details).
1503 uClibc's locale support is still under development. For example,
1504 codesets using shift states are not currently supported. Support is
1505 planned in the next iteration of locale support.
1507 Answer Y to enable locale support. Most people will answer N.
1511 prompt "Locale data"
1512 depends on UCLIBC_HAS_LOCALE
1513 default UCLIBC_BUILD_ALL_LOCALE
1515 config UCLIBC_BUILD_ALL_LOCALE
1517 depends on UCLIBC_HAS_LOCALE
1519 This builds all the locales that are available on your
1522 config UCLIBC_BUILD_MINIMAL_LOCALE
1523 bool "Only selected locales"
1524 depends on UCLIBC_HAS_LOCALE
1526 If you do not need all locales that are available on your
1527 host-box, then set this to 'Y'.
1529 config UCLIBC_PREGENERATED_LOCALE_DATA
1530 bool "Use Pre-generated Locale Data"
1531 depends on UCLIBC_HAS_LOCALE && !TARGET_metag
1533 Use pre-built locale data.
1535 Note that these pregenerated locales are sensitive to your
1536 target architecture (endianess, bitcount).
1538 Saying N here is highly recommended.
1542 config UCLIBC_BUILD_MINIMAL_LOCALES
1543 string "locales to use"
1544 depends on UCLIBC_BUILD_MINIMAL_LOCALE
1547 Space separated list of locales to use.
1554 config UCLIBC_DOWNLOAD_PREGENERATED_LOCALE_DATA
1555 bool "Automagically Download the Pre-generated Locale Data (if necessary)"
1556 depends on UCLIBC_PREGENERATED_LOCALE_DATA
1558 If you would like the build process to use 'wget' to automatically
1559 download the pregenerated locale data, enable this option. Otherwise
1560 you will need to obtain the locale data yourself from:
1561 http://www.uclibc.org/downloads/uClibc-locale-*.tgz
1562 and place the uClibc-locale-*.tgz tarball in the extra/locale/
1565 Note that the use of pregenerated locale data is discouraged.
1567 config UCLIBC_HAS_XLOCALE
1568 bool "Extended Locale Support (experimental/incomplete)"
1569 depends on UCLIBC_HAS_LOCALE
1571 Answer Y to enable extended locale support similar to that provided
1572 by glibc. This is primarily intended to support libstd++
1574 However, it also allows thread-specific locale selection via
1577 Most people will answer N.
1579 config UCLIBC_HAS_HEXADECIMAL_FLOATS
1580 bool "Support hexadecimal float notation"
1581 depends on UCLIBC_HAS_CTYPE_TABLES
1582 depends on UCLIBC_HAS_FLOATS
1584 Answer Y to enable support for hexadecimal float notation in the
1585 (wchar and) char string to floating point conversion functions, as
1586 well as support for the %a and %A conversion specifiers in the
1587 *printf() and *scanf() functions.
1589 Most people will answer N.
1591 config UCLIBC_HAS_GLIBC_DIGIT_GROUPING
1592 bool "Support glibc's \"'\" flag for allowing locale-specific digit grouping"
1593 depends on UCLIBC_HAS_LOCALE
1594 depends on UCLIBC_HAS_FLOATS
1596 Answer Y to enable support for glibc's \"'\" flag for allowing
1597 locale-specific digit grouping in base 10 integer conversions and
1598 appropriate floating point conversions in the *printf() and *scanf()
1601 Most people will answer N.
1603 config UCLIBC_HAS_SCANF_LENIENT_DIGIT_GROUPING
1604 bool "Do not require digit grouping when the \"'\" flag is specified"
1605 depends on UCLIBC_HAS_GLIBC_DIGIT_GROUPING
1608 Answer Y to make digit grouping optional when the \"'\" flag is
1610 This is the standard glibc behavior. If the initial string of digits
1611 exceeds the maximum group number, the input will be treated as a
1612 normal non-grouped number.
1614 Most people will answer N.
1616 config UCLIBC_HAS_GLIBC_CUSTOM_PRINTF
1617 bool "Support glibc's register_printf_function() (glibc-compat)"
1618 depends on !USE_OLD_VFPRINTF
1620 Answer Y to support glibc's register_printf_function() to allow an
1621 application to add its own printf conversion specifiers.
1622 parse_printf_format() is also enabled.
1624 NOTE: Limits the number or registered specifiers to 10.
1625 NOTE: Requires new conversion specifiers to be ASCII
1626 characters (0-0x7f). This is to avoid problems with processing
1627 format strings in locales with different multibyte conversions.
1629 Most people will answer N.
1631 config USE_OLD_VFPRINTF
1632 bool "Use the old vfprintf implementation"
1633 depends on !UCLIBC_HAS_WCHAR
1635 Set to true to use the old vfprintf instead of the new. This is
1636 roughly C89 compliant with some extensions, and is much smaller.
1637 However, it does not support wide chars, positional args, or glibc
1638 custom printf specifiers.
1640 Most people will answer N.
1642 config UCLIBC_PRINTF_SCANF_POSITIONAL_ARGS
1643 int "Maximum number of positional args. Either 0 or >= 9."
1644 depends on !USE_OLD_VFPRINTF
1647 Set the maximum number of positional args supported by the
1648 printf/scanf functions. The Single Unix Specification Version 3
1649 requires a minimum value of 9. Setting this to a value lower than
1650 9 will disable positional arg support and cause the NL_ARGMAX macro
1651 in limits.h to be #undef'd.
1653 WARNING! The workspace to support positional args is currently
1654 allocated on the stack. You probably don't want to set
1655 this to too high a value.
1657 Most people will answer 9.
1660 prompt "Stdio buffer size"
1661 default UCLIBC_HAS_STDIO_BUFSIZ_4096
1663 Please select a value for BUFSIZ. This will be used by the
1664 stdio subsystem as the default buffer size for a file, and
1665 affects fopen(), setvbuf(), etc.
1667 NOTE: Setting this to 'none' will disable buffering completely.
1668 However, BUFSIZ will still be defined in stdio.h as 256 because
1669 many applications use this value.
1671 config UCLIBC_HAS_STDIO_BUFSIZ_NONE
1672 bool "none (WARNING - BUFSIZ will be 256 in stdio.h)"
1673 depends on !UCLIBC_HAS_WCHAR
1675 config UCLIBC_HAS_STDIO_BUFSIZ_256
1676 bool "256 (minimum ANSI/ISO C99 value)"
1678 config UCLIBC_HAS_STDIO_BUFSIZ_512
1681 config UCLIBC_HAS_STDIO_BUFSIZ_1024
1684 config UCLIBC_HAS_STDIO_BUFSIZ_2048
1687 config UCLIBC_HAS_STDIO_BUFSIZ_4096
1690 config UCLIBC_HAS_STDIO_BUFSIZ_8192
1693 # If you add more choices, you will need to update uClibc_stdio.h.
1698 prompt "Stdio builtin buffer size (uClibc-specific)"
1699 depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
1700 default UCLIBC_HAS_STDIO_BUILTIN_BUFFER_NONE
1702 When a FILE is created with fopen(), an attempt is made to allocate
1703 a BUFSIZ buffer for it. If the allocation fails, fopen() will still
1704 succeed but the FILE will be unbuffered.
1706 This option adds a small amount of space to each FILE to act as an
1707 emergency buffer in the event of a buffer allocation failure.
1709 Most people will answer None.
1711 config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_NONE
1714 config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_4
1717 config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_8
1720 # If you add more choices, you will need to update uClibc_stdio.h.
1724 config UCLIBC_HAS_STDIO_SHUTDOWN_ON_ABORT
1725 bool "Attempt to shutdown stdio subsystem when abort() is called."
1727 ANSI/ISO C99 requires abort() to be asyn-signal-safe. So there was
1728 a behavioral change made in SUSv3. Previously, abort() was required
1729 to have the affect of fclose() on all open streams. The wording has
1730 been changed to "may" from "shall".
1732 Most people will answer N.
1734 config UCLIBC_HAS_STDIO_GETC_MACRO
1735 bool "Provide a macro version of getc()"
1736 depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
1739 Provide a macro version of getc().
1741 Most people will answer Y.
1743 config UCLIBC_HAS_STDIO_PUTC_MACRO
1744 bool "Provide a macro version of putc()"
1745 depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
1748 Provide a macro version of putc().
1750 Most people will answer Y.
1752 config UCLIBC_HAS_STDIO_AUTO_RW_TRANSITION
1753 bool "Support auto-r/w transition"
1756 Answer Y to enable the stdio subsystem to automaticly transition
1757 between reading and writing. This relaxes the ANSI/ISO C99
1760 When a file is opened with update mode ('+' as the second or third
1761 character in the list of mode argument values), both input and output
1762 may be performed on the associated stream. However, output shall not
1763 be directly followed by input without an intervening call to the
1764 fflush function or to a file positioning function (fseek, fsetpos,
1765 or rewind), and input shall not be directly followed by output without
1766 an intervening call to a file positioning function, unless the input
1767 operation encounters endÂofÂfile.
1769 Most people will answer Y.
1771 config UCLIBC_HAS_FOPEN_LARGEFILE_MODE
1772 bool "Support an fopen() 'F' flag for large file mode (uClibc-specific)"
1773 depends on UCLIBC_HAS_LFS
1775 Answer Y to enable a uClibc-specific extension to allow passing an
1776 additional 'F' flag in the mode string for fopen() to specify that
1777 the file should be open()ed with the O_LARGEFILE flag set.
1779 Most people will answer N.
1781 config UCLIBC_HAS_FOPEN_EXCLUSIVE_MODE
1782 bool "Support an fopen() 'x' flag for exclusive mode (glibc-compat)"
1784 Answer Y to support a glibc extension to allow passing
1785 additional 'x' flag in the mode string for fopen() to specify that
1786 the file should be open()ed with the O_EXCL flag set.
1788 Most people will answer N.
1790 config UCLIBC_HAS_FOPEN_CLOSEEXEC_MODE
1791 bool "Support an fopen() 'e' flag for close-on-exec mode (glibc-compat)"
1793 Answer Y to support a glibc extension to allow passing
1794 additional 'e' flag in the mode string for fopen() to specify that
1795 the file should be open()ed with the O_CLOEXEC flag set.
1797 Most people will answer N.
1799 config UCLIBC_HAS_GLIBC_CUSTOM_STREAMS
1800 bool "Support fmemopen(), open_memstream(), and fopencookie() (glibc-compat)"
1802 Answer Y to support the glibc 'custom stream' extension functions
1803 fmemopen(), open_memstream(), and fopencookie().
1805 NOTE: There are some minor differences regarding seeking behavior.
1807 Most people will answer N.
1809 config UCLIBC_HAS_PRINTF_M_SPEC
1810 bool "Support the '%m' specifier in printf format strings (glibc-compat)"
1812 Answer Y to support a glibc extension to interpret '%m' in printf
1813 format strings as an instruction to output the error message string
1814 (as generated by strerror) corresponding to the current value of
1817 Most people will answer N.
1819 config UCLIBC_HAS_ERRNO_MESSAGES
1820 bool "Include the errno message text in the library"
1823 Answer Y if you want to include the errno message text in the
1824 library. This adds about 3K to the library, but enables strerror()
1825 to generate text other than 'Unknown error <number>'.
1827 Most people will answer Y.
1829 config UCLIBC_HAS_SYS_ERRLIST
1830 bool "Support sys_errlist[] (obsolete-compat)"
1831 depends on UCLIBC_HAS_ERRNO_MESSAGES
1833 Answer Y if you want to support the obsolete sys_errlist[].
1834 This adds about 0.5k to the library, except for the mips
1835 arch where it adds over 4K.
1837 WARNING! In the future, support for sys_errlist[] may be unavailable
1838 in at least some configurations. In fact, it may be removed
1841 Most people will answer N.
1843 Application writers: use the strerror(3) function.
1845 config UCLIBC_HAS_SIGNUM_MESSAGES
1846 bool "Include the signum message text in the library"
1849 Answer Y if you want to include the signum message text in the
1850 library. This adds about 0.5K to the library, but enables strsignal()
1851 to generate text other than 'Unknown signal <number>'.
1853 Most people will answer Y.
1855 config UCLIBC_HAS_SYS_SIGLIST
1856 bool "Support sys_siglist[] (bsd-compat)"
1857 depends on UCLIBC_HAS_SIGNUM_MESSAGES
1859 Answer Y if you want to support sys_siglist[].
1861 WARNING! In the future, support for sys_siglist[] may be unavailable
1862 in at least some configurations. In fact, it may be removed
1865 Most people will answer N.
1867 config UCLIBC_HAS_GETTEXT_AWARENESS
1868 bool "Include gettext awareness"
1869 depends on UCLIBC_HAS_LOCALE && UCLIBC_MJN3_ONLY
1871 NOTE!!! Not yet integrated with strerror and strsignal. NOTE!!!
1873 Answer Y if you want to include weak stub gettext support and
1874 make the *strerror*() and strsignal() functions gettext-aware.
1876 Currently, to get functional gettext functionality you will need
1879 Most people will answer N.
1881 config UCLIBC_HAS_GNU_GETOPT
1882 bool "Support gnu getopt"
1885 Answer Y if you want to include full gnu getopt() instead of a
1886 (much smaller) SUSv3 compatible getopt().
1887 Note that getopt_long, getopt_long_only as well as getsubopt
1888 are implemented on top of this choice.
1890 Most people will answer Y.
1892 config UCLIBC_HAS_GETOPT_LONG
1893 bool "Support getopt_long/getopt_long_only (glibc-compat)"
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 getsubopt"
1905 Answer Y if you want to include getsubopt().
1907 Most people will answer Y.
1913 config UCLIBC_HAS_REGEX
1914 bool "Regular Expression Support"
1917 POSIX regular expression code is really big -- 53k all by itself.
1918 If you don't use regular expressions, turn this off and save space.
1919 Of course, if you only statically link, leave this on, since it will
1920 only be included in your apps if you use regular expressions.
1922 config UCLIBC_HAS_FNMATCH
1923 bool "fnmatch Support"
1928 config UCLIBC_HAS_WORDEXP
1929 bool "Support the wordexp() interface"
1930 depends on UCLIBC_HAS_GLOB
1932 The SuSv3 wordexp() interface performs word expansions per the Shell
1933 and Utilities volume of IEEE Std 1003.1-2001, Section 2.6. It is
1934 intended for use by applications that want to implement all of the
1935 standard Bourne shell expansions on input data.
1937 This interface is rarely used, and very large. Unless you have a
1938 pressing need for wordexp(), you should probably answer N.
1940 config UCLIBC_HAS_NFTW
1941 bool "Support the nftw() interface"
1943 The SuSv3 nftw() interface is used to recursively descend
1944 directory paths while repeatedly calling a function.
1946 This interface is rarely used, and adds around 4.5k. Unless you have
1947 a pressing need for nftw(), you should probably answer N.
1949 config UCLIBC_HAS_FTW
1950 bool "Support the ftw() interface (SUSv4-obsolete)"
1951 depends on UCLIBC_SUSV4_LEGACY
1953 The SuSv3 ftw() interface is used to recursively descend
1954 directory paths while repeatedly calling a function.
1956 This interface is rarely used, and adds around 4.5k. Unless you have
1957 a pressing need for ftw(), you should probably answer N.
1959 config UCLIBC_HAS_FTS
1960 bool "Support the fts() interface (bsd-compat)"
1962 The fts functions are provided for traversing UNIX file hierarchies.
1964 This interface is currently used by the elfutils and adds
1966 You should port your application to use the POSIX nftw()
1969 Unless you need to build/use elfutils, you should prolly answer N.
1971 config UCLIBC_HAS_GLOB
1972 bool "Support the glob() interface"
1973 depends on UCLIBC_HAS_FNMATCH
1977 The glob interface is somewhat large (weighing in at about 2,5k). It
1978 is used fairly often, but is an option since people wanting to go for
1979 absolute minimum size may wish to omit it.
1981 Most people will answer Y.
1983 config UCLIBC_HAS_GNU_GLOB
1984 bool "Support gnu glob() interface"
1985 depends on UCLIBC_HAS_GLOB
1987 The gnu glob interface is somewhat larger (weighing in at about 4,2k)
1988 than it's SuSv3 counterpart (and is out of date). It is an old copy
1989 from glibc and does not support all the GNU specific options.
1991 Answer Y if you want to include full gnu glob() instead of the smaller
1992 SUSv3 compatible glob().
1994 Most people will answer N.
2001 menu "Library Installation Options"
2003 config RUNTIME_PREFIX
2004 string "uClibc runtime library directory"
2005 default "/usr/$(TARGET_ARCH)-linux-uclibc/"
2007 RUNTIME_PREFIX is the directory into which the uClibc runtime
2008 libraries will be installed. The result will look something
2011 lib/ <contains all runtime libraries>
2012 usr/bin/ldd <the ldd utility program>
2013 sbin/ldconfig <the ldconfig utility program>
2014 This value is used by the 'make install' Makefile target. Since this
2015 directory is compiled into the shared library loader, you will need to
2016 recompile uClibc if you change this value...
2018 For a typical target system this should be set to "/", such that
2019 'make install' will install /lib/libuClibc-<VERSION>.so
2022 string "uClibc development environment directory"
2023 default "/usr/$(TARGET_ARCH)-linux-uclibc/usr/"
2025 DEVEL_PREFIX is the directory into which the uClibc development
2026 environment will be installed. The result will look something
2029 lib/ <contains static libs>
2030 include/ <Where all the header files go>
2031 This value is used by the 'make install' Makefile target when
2032 installing a uClibc development environment.
2034 For a typical target system this should be set to "/usr", such that
2035 'make install' will install /usr/include/<header files>.
2038 string "library path component"
2041 Path component where libraries reside.
2043 For a typical target system this should be set to "lib", such that
2044 'make install' will install libraries to "/lib" and "/usr/lib"
2046 DEVEL_PREFIX/MULTILIB_DIR
2047 RUNTIME_PREFIX/MULTILIB_DIR
2049 Other settings may include "lib32" or "lib64".
2051 config HARDWIRED_ABSPATH
2052 bool "Hardwire absolute paths into linker scripts"
2055 This prepends absolute paths to the libraries mentioned in linker
2056 scripts such as libc.so.
2058 This is a build time optimization. It has no impact on dynamic
2059 linking at runtime, which doesn't use linker scripts.
2061 You must disable this to use uClibc with old non-sysroot toolchains,
2062 such as the prebuilt binary cross compilers at:
2063 http://uclibc.org/downloads/binaries
2065 The amount of time saved by this optimization is actually too small to
2066 measure. The linker just had to search the library path to find the
2067 linker script, so the dentries are cache hot if it has to search the
2068 same path again. But it's what glibc does, so we do it too.
2073 menu "Security options"
2075 config UCLIBC_BUILD_PIE
2076 bool "Build utilities as ET_DYN/PIE executables"
2077 depends on HAVE_SHARED
2078 depends on TARGET_arm || TARGET_frv || TARGET_i386 || TARGET_mips || TARGET_powerpc
2079 select FORCE_SHAREABLE_TEXT_SEGMENTS
2081 If you answer Y here, ldd and iconv are built as ET_DYN/PIE
2084 It requires gcc-3.4 and binutils-2.15 (for arm 2.16) or later.
2085 More about ET_DYN/PIE binaries on <http://pax.grsecurity.net/> .
2087 WARNING: This option also enables FORCE_SHAREABLE_TEXT_SEGMENTS, so
2088 all libraries have to be built with -fPIC or -fpic, and all
2089 assembler functions must be written as position independent
2092 config UCLIBC_HAS_ARC4RANDOM
2093 bool "Include the arc4random() function"
2095 Answer Y to support the OpenBSD-like arc4random() function. This
2096 function picks a random number between 0 and N, and will always return
2097 something even if the random driver is dead. If urandom fails then
2098 gettimeofday(2) will be used as the random seed. This function is
2099 designed to be more dependable than invoking /dev/urandom directly.
2100 OpenSSL and OpenNTPD currently support this function.
2102 Most people will answer N.
2104 config ARC4RANDOM_USES_NODEV
2105 bool "Do not use /dev/urandom with arc4random()"
2106 depends on UCLIBC_HAS_ARC4RANDOM
2108 Answer Y to use gettimeofday(2) and getpid(2) exclusively for
2109 arc4random(). This is not a bad idea for a diskless system, but
2110 it uses a lot of syscalls to stir each array element.
2112 Most people will answer N.
2117 config UCLIBC_HAS_SSP
2118 bool "Support for GCC stack smashing protector"
2119 depends on !HAVE_NO_SSP
2121 Add code to support GCC's -fstack-protector[-all] option to uClibc.
2122 This requires GCC 4.1 or newer. GCC does not have to provide libssp,
2123 the needed functions are added to ldso/libc instead.
2125 GCC's stack protector is a reimplementation of IBM's propolice.
2126 See http://www.trl.ibm.com/projects/security/ssp/ and
2127 http://www.linuxfromscratch.org/hints/downloads/files/ssp.txt
2130 Note that NOEXECSTACK on a kernel with address space randomization
2131 is generally sufficient to prevent most buffer overflow exploits
2132 without increasing code size. This option essentially adds debugging
2135 Most people will answer N.
2137 config UCLIBC_HAS_SSP_COMPAT
2138 bool "Support for gcc-3.x propolice smashing stack protector"
2139 depends on UCLIBC_HAS_SSP
2141 Add gcc-3.x propolice smashing stack protector to the library.
2143 This requires a patched version of GCC, supporting the
2144 -fstack-protector[-all] options, with the __guard and
2145 __stack_smash_handler functions removed from libgcc.
2146 These functions are added to ldso/libc instead.
2148 More information at:
2149 <http://www.research.ibm.com/trl/projects/security/ssp/>
2151 Most people will answer N.
2153 config SSP_QUICK_CANARY
2154 bool "Use simple guard values without accessing /dev/urandom"
2155 depends on UCLIBC_HAS_SSP
2157 Use gettimeofday(2) to define the __guard without accessing
2159 WARNING: This makes smashing stack protector vulnerable to timing
2161 Most people will answer N.
2164 prompt "Propolice protection blocking signal"
2165 depends on UCLIBC_HAS_SSP
2167 default PROPOLICE_BLOCK_SEGV
2169 "abort" use SIGABRT to block offending programs.
2170 This is the default implementation.
2172 "segfault" use SIGSEGV to block offending programs.
2173 Use this for debugging.
2175 If unsure, answer "abort".
2177 config PROPOLICE_BLOCK_ABRT
2180 config PROPOLICE_BLOCK_SEGV
2185 config UCLIBC_BUILD_SSP
2186 bool "Build uClibc with -fstack-protector"
2187 depends on UCLIBC_HAS_SSP
2189 Build all uClibc libraries and executables with -fstack-protector,
2190 adding extra stack overflow checking to most uClibc functions.
2192 config UCLIBC_BUILD_RELRO
2193 bool "Build uClibc with linker option -z RELRO"
2194 depends on HAVE_SHARED
2197 Build all libraries and executables with "ld -z relro".
2199 This tells the linker to mark chunks of an executable or shared
2200 library read-only after applying dynamic relocations. (This comes
2201 up when a global const variable is initialized to the address of a
2202 function or the value of another global variable.)
2204 This is a fairly obscure option the ld man page doesn't even bother
2205 to document properly. It's a security paranoia issue that's more
2206 likely to consume memory (by allocating an extra page) rather than
2209 This is explained in more depth at
2210 http://www.airs.com/blog/archives/189
2212 Nobody is likely to care whether you say Y or N here.
2214 config UCLIBC_BUILD_NOW
2215 bool "Build uClibc with linker option -z NOW"
2216 depends on HAVE_SHARED
2218 Build all libraries and executables with "ld -z now".
2220 This tells the linker to resolve all symbols when the library is
2221 first loaded, rather than when each function is first called. This
2222 increases start-up latency by a few microseconds and may do
2223 unnecessary work (resolving symbols that are never used), but the
2224 realtime people like it for making microbenchmark timings slightly
2225 more predictable and in some cases it can be slightly faster due to
2226 CPU cache behavior (not having to fault the linker back in to do
2227 lazy symbol resolution).
2229 Most people can't tell the difference between selecting Y or N here.
2231 config UCLIBC_BUILD_NOEXECSTACK
2232 bool "Build uClibc with noexecstack marking"
2235 Mark all assembler files as noexecstack, which will mark uClibc
2236 as not requiring an executable stack. (This doesn't prevent other
2237 files you link against from claiming to need an executable stack, it
2238 just won't cause uClibc to request it unnecessarily.)
2240 This is a security thing to make buffer overflows harder to exploit.
2241 By itself, it's kind of useless, as Linus Torvalds explained in 1998:
2242 http://old.lwn.net/1998/0806/a/linus-noexec.html
2244 It only actually provides any security when combined with address
2245 space randomization, explained here: http://lwn.net/Articles/121845/
2247 Address space randomization is on by default in current linux
2248 kernels (although it can be disabled using the option
2251 You should probably say Y.
2255 menu "Development/debugging options"
2257 config CROSS_COMPILER_PREFIX
2258 string "Cross-compiling toolchain prefix"
2261 The prefix used to execute your cross-compiling toolchain. For
2262 example, if you run 'arm-linux-uclibc-gcc' to compile something,
2263 then enter 'arm-linux-uclibc-' here.
2265 config UCLIBC_EXTRA_CFLAGS
2266 string "Extra CFLAGS"
2269 Add any additional CFLAGS to be used to build uClibc.
2272 bool "Enable debugging symbols"
2273 select EXTRA_WARNINGS
2275 Say Y here if you wish to compile uClibc with debugging symbols.
2276 This will allow you to use a debugger to examine uClibc internals
2277 while applications are running. This increases the size of the
2278 library considerably and should only be used when doing development.
2279 If you are doing development and want to debug uClibc, answer Y.
2281 Otherwise, answer N.
2284 bool "Build pthread with debugging output"
2285 depends on UCLIBC_HAS_THREADS && UCLIBC_HAS_LINUXTHREADS
2287 Enable debug output in libpthread. This is only useful when doing
2288 development in libpthread itself.
2290 Otherwise, answer N.
2293 bool "Strip libraries and executables"
2297 Say Y here if you do wish to strip all uClibc libraries and
2298 executables. No stripping increases the size of the binaries
2299 considerably, but makes it possible to debug uClibc libraries.
2300 Most people will answer Y.
2303 bool "Build with run-time assertion testing"
2305 Say Y here to include runtime assertion tests.
2306 This enables runtime assertion testing in some code, which can
2307 increase the size of the library and incur runtime overhead.
2308 If you say N, then this testing will be disabled.
2310 config SUPPORT_LD_DEBUG
2311 bool "Build the shared library loader with debugging support"
2312 depends on HAVE_SHARED
2314 Answer Y here to enable all the extra code needed to debug the uClibc
2315 native shared library loader. The level of debugging noise that is
2316 generated depends on the LD_DEBUG environment variable... Just set
2317 LD_DEBUG to something like: 'LD_DEBUG=token1,token2,.. prog' to
2318 debug your application. Diagnostic messages will then be printed to
2321 For now these debugging tokens are available:
2322 detail provide more information for some options
2323 move display copy processing
2324 symbols display symbol table processing
2325 reloc display relocation processing; detail shows the
2327 nofixups never fixes up jump relocations
2328 bindings displays the resolve processing (function calls);
2329 detail shows the relocation patch
2330 all Enable everything!
2332 The additional environment variable:
2333 LD_DEBUG_OUTPUT=file
2334 redirects the diagnostics to an output file created using
2335 the specified name and the process id as a suffix.
2337 An excellent start is simply:
2338 $ LD_DEBUG=binding,move,symbols,reloc,detail ./appname
2339 or to log everything to a file named 'logfile', try this
2340 $ LD_DEBUG=all LD_DEBUG_OUTPUT=logfile ./appname
2342 If you are doing development and want to debug uClibc's shared library
2343 loader, answer Y. Mere mortals answer N.
2345 config SUPPORT_LD_DEBUG_EARLY
2346 bool "Build the shared library loader with early debugging support"
2347 depends on HAVE_SHARED
2349 Answer Y here to if you find the uClibc shared library loader is
2350 crashing or otherwise not working very early on. This is typical
2351 only when starting a new port when you haven't figured out how to
2352 properly get the values for argc, argv, environ, etc. This method
2353 allows a degree of visibility into the very early shared library
2354 loader initialization process. If you are doing development and want
2355 to debug the uClibc shared library loader early initialization,
2356 answer Y. Mere mortals answer N.
2358 config UCLIBC_MALLOC_DEBUGGING
2359 bool "Build malloc with debugging support"
2360 depends on MALLOC || MALLOC_STANDARD
2363 Answer Y here to compile extra debugging support code into malloc.
2364 Malloc debugging output may then be enabled at runtime using the
2365 MALLOC_DEBUG environment variable.
2367 The value of MALLOC_DEBUG should be an integer, which is interpreted
2368 as a bitmask with the following bits:
2369 1 - do extra consistency checking
2370 2 - output messages for malloc/free calls and OS
2372 4 - output messages for the `MMB' layer
2373 8 - output messages for internal malloc heap manipulation
2376 Because this increases the size of malloc appreciably (due to strings
2377 etc), you should say N unless you need to debug a malloc problem.
2379 config UCLIBC_HAS_BACKTRACE
2380 bool "Add support for application self-debugging"
2381 depends on HAVE_SHARED
2383 Answer Y here to compile support for application self-debugging, by adding
2384 a new shared object "libubacktrace.so" that provides the following new
2386 backtrace, backtrace_symbols, backtrace_symbols_fd
2388 The backtrace functionality is currently supported on SH platform, and it
2389 based on dwarf2 informations to properly work, so any application that
2390 want to use backtrace needs to be built with -fexceptions flag.
2392 The symbol names may be unavailable without the use of special linker
2393 options. For systems using the GNU linker, it is necessary to use the
2394 -rdynamic linker option too. Note that names of "static" functions are not
2395 exposed, and won't be available in the backtrace.
2398 string "Compiler Warnings"
2401 Set this to the set of compiler warnings you wish to see while compiling.
2403 config EXTRA_WARNINGS
2404 bool "Enable extra annoying warnings"
2406 If you wish to build with extra warnings enabled, say Y here.
2409 bool "Compile all sources at once into an object"
2411 Set this to compile all sources at once into an object (IMA).
2412 This mode of compilation uses alot of memory but may produce
2415 Note that you need a very recent GCC for this to work, like
2416 gcc >= 4.3 plus eventually some patches.
2418 If unsure, keep the default of N.
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