123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704705706707708709710711712713714715716717718719720721722723724725726727728729730731732733734735736737738739740741742743744745746747748749750751752753754755756757758759760761762763764765766767768769770771772773774775776777778779780781782783784785786787788789790791792793794795796797798799800801802803804805806807808809810811812813814815816817818819820821822823824825826827828829830831832833834835836837838839840841842843844845846847848849850851852853854855856857858859860861862863864865866867868869870871872873874875876877878879880881882883884885886887888889890891892893894895896897898899900901902903904905906907908909910911912913914915916917918919920921922923924925926927928929930931932933934935936937938939940941942943944945946947948949950951952953954955956957958959960961962963964965966967968969970971972973974975976977978979980981982983984985986987988989990991992993994995996997998999100010011002100310041005100610071008100910101011101210131014101510161017101810191020102110221023102410251026102710281029103010311032103310341035103610371038103910401041104210431044104510461047104810491050105110521053105410551056105710581059106010611062106310641065106610671068106910701071107210731074107510761077107810791080108110821083108410851086108710881089109010911092109310941095109610971098109911001101110211031104110511061107110811091110111111121113111411151116111711181119112011211122112311241125112611271128112911301131113211331134113511361137113811391140114111421143114411451146114711481149115011511152115311541155115611571158115911601161116211631164116511661167116811691170117111721173117411751176117711781179118011811182118311841185118611871188118911901191119211931194119511961197119811991200120112021203120412051206120712081209121012111212121312141215121612171218121912201221122212231224122512261227122812291230123112321233123412351236123712381239124012411242124312441245124612471248124912501251125212531254125512561257125812591260126112621263126412651266126712681269127012711272127312741275127612771278127912801281128212831284128512861287128812891290129112921293129412951296129712981299130013011302130313041305130613071308130913101311131213131314131513161317131813191320132113221323132413251326132713281329133013311332133313341335133613371338133913401341134213431344134513461347134813491350135113521353135413551356135713581359136013611362136313641365136613671368136913701371137213731374137513761377137813791380138113821383138413851386138713881389139013911392139313941395139613971398139914001401140214031404140514061407140814091410141114121413141414151416141714181419142014211422142314241425142614271428142914301431143214331434143514361437143814391440144114421443144414451446144714481449145014511452145314541455145614571458145914601461146214631464146514661467146814691470147114721473147414751476147714781479148014811482148314841485148614871488148914901491149214931494149514961497149814991500150115021503150415051506150715081509151015111512151315141515151615171518151915201521152215231524152515261527152815291530153115321533153415351536153715381539154015411542154315441545154615471548154915501551155215531554155515561557155815591560156115621563156415651566156715681569157015711572157315741575157615771578157915801581158215831584158515861587158815891590159115921593159415951596159715981599160016011602160316041605160616071608160916101611161216131614161516161617161816191620162116221623162416251626162716281629163016311632163316341635163616371638163916401641164216431644164516461647164816491650165116521653165416551656165716581659166016611662166316641665166616671668166916701671167216731674167516761677167816791680168116821683168416851686168716881689169016911692169316941695169616971698169917001701170217031704170517061707170817091710171117121713171417151716171717181719172017211722172317241725172617271728172917301731173217331734173517361737173817391740174117421743174417451746174717481749175017511752175317541755175617571758175917601761176217631764176517661767176817691770177117721773177417751776177717781779178017811782178317841785178617871788178917901791179217931794179517961797179817991800180118021803180418051806180718081809181018111812181318141815181618171818181918201821182218231824182518261827182818291830183118321833183418351836183718381839184018411842184318441845184618471848184918501851185218531854185518561857185818591860186118621863186418651866186718681869187018711872187318741875187618771878187918801881188218831884188518861887188818891890189118921893189418951896189718981899190019011902190319041905190619071908190919101911191219131914191519161917191819191920192119221923192419251926192719281929193019311932193319341935193619371938193919401941194219431944194519461947194819491950195119521953195419551956195719581959196019611962196319641965196619671968196919701971197219731974197519761977197819791980198119821983198419851986198719881989199019911992199319941995199619971998199920002001200220032004200520062007200820092010201120122013201420152016201720182019202020212022202320242025202620272028202920302031203220332034203520362037203820392040204120422043204420452046204720482049205020512052205320542055205620572058205920602061206220632064206520662067206820692070207120722073207420752076207720782079208020812082208320842085208620872088208920902091209220932094209520962097209820992100210121022103210421052106210721082109211021112112211321142115211621172118211921202121212221232124212521262127212821292130213121322133213421352136213721382139214021412142214321442145214621472148214921502151215221532154215521562157215821592160216121622163216421652166216721682169217021712172217321742175217621772178217921802181218221832184218521862187218821892190219121922193219421952196219721982199220022012202220322042205220622072208220922102211221222132214221522162217221822192220222122222223222422252226222722282229223022312232223322342235223622372238223922402241224222432244224522462247224822492250225122522253225422552256225722582259226022612262226322642265226622672268226922702271227222732274227522762277227822792280228122822283228422852286228722882289229022912292229322942295229622972298229923002301230223032304230523062307230823092310231123122313231423152316231723182319232023212322232323242325232623272328232923302331233223332334233523362337233823392340234123422343234423452346234723482349235023512352 |
- #
- # For a description of the syntax of this configuration file,
- # see extra/config/Kconfig-language.txt
- #
- mainmenu "uClibc-ng $VERSION C Library Configuration"
- config DESIRED_TARGET_ARCH
- string
- option env="ARCH"
- config VERSION
- string
- option env="VERSION"
- choice
- prompt "Target Architecture"
- default TARGET_alpha if DESIRED_TARGET_ARCH = "alpha"
- default TARGET_arc if DESIRED_TARGET_ARCH = "arc"
- default TARGET_arm if DESIRED_TARGET_ARCH = "arm"
- default TARGET_avr32 if DESIRED_TARGET_ARCH = "avr32"
- default TARGET_bfin if DESIRED_TARGET_ARCH = "bfin"
- default TARGET_cris if DESIRED_TARGET_ARCH = "cris"
- default TARGET_frv if DESIRED_TARGET_ARCH = "frv"
- default TARGET_h8300 if DESIRED_TARGET_ARCH = "h8300"
- default TARGET_hppa if DESIRED_TARGET_ARCH = "hppa"
- default TARGET_i386 if DESIRED_TARGET_ARCH = "i386"
- default TARGET_ia64 if DESIRED_TARGET_ARCH = "ia64"
- default TARGET_lm32 if DESIRED_TARGET_ARCH = "lm32"
- default TARGET_m68k if DESIRED_TARGET_ARCH = "m68k"
- default TARGET_metag if DESIRED_TARGET_ARCH = "metag"
- default TARGET_microblaze if DESIRED_TARGET_ARCH = "microblaze"
- default TARGET_mips if DESIRED_TARGET_ARCH = "mips"
- default TARGET_nds32 if DESIRED_TARGET_ARCH = "nds32"
- default TARGET_nios2 if DESIRED_TARGET_ARCH = "nios2"
- default TARGET_or1k if DESIRED_TARGET_ARCH = "or1k"
- default TARGET_powerpc if DESIRED_TARGET_ARCH = "powerpc"
- default TARGET_sh if DESIRED_TARGET_ARCH = "sh"
- default TARGET_sparc if DESIRED_TARGET_ARCH = "sparc"
- default TARGET_x86_64 if DESIRED_TARGET_ARCH = "x86_64"
- default TARGET_xtensa if DESIRED_TARGET_ARCH = "xtensa"
- help
- The architecture of your target.
- config TARGET_alpha
- bool "alpha"
- config TARGET_arc
- bool "arc"
- config TARGET_arm
- bool "arm"
- config TARGET_avr32
- bool "avr32"
- config TARGET_bfin
- bool "bfin"
- # someone could sync this tree:
- # http://linux-c6x.org/git/?p=uClibc.git;a=summary
- config TARGET_c6x
- bool "c6x"
- config TARGET_cris
- bool "cris"
- config TARGET_frv
- bool "frv"
- config TARGET_h8300
- bool "h8300"
- config TARGET_hppa
- bool "hppa"
- config TARGET_i386
- bool "i386"
- config TARGET_ia64
- bool "ia64"
- config TARGET_lm32
- bool "lm32"
- config TARGET_m68k
- bool "m68k"
- config TARGET_metag
- bool "metag"
- config TARGET_microblaze
- bool "microblaze"
- config TARGET_mips
- bool "mips"
- config TARGET_nds32
- bool "nds32"
- config TARGET_nios2
- bool "nios2"
- config TARGET_or1k
- bool "or1k"
- config TARGET_powerpc
- bool "powerpc"
- config TARGET_sh
- bool "superh"
- config TARGET_sparc
- bool "sparc"
- config TARGET_x86_64
- bool "x86_64"
- config TARGET_xtensa
- bool "xtensa"
- endchoice
- menu "Target Architecture Features and Options"
- if TARGET_alpha
- source "extra/Configs/Config.alpha"
- endif
- if TARGET_arm
- source "extra/Configs/Config.arm"
- endif
- if TARGET_avr32
- source "extra/Configs/Config.avr32"
- endif
- if TARGET_bfin
- source "extra/Configs/Config.bfin"
- endif
- if TARGET_cris
- source "extra/Configs/Config.cris"
- endif
- if TARGET_frv
- source "extra/Configs/Config.frv"
- endif
- if TARGET_h8300
- source "extra/Configs/Config.h8300"
- endif
- if TARGET_hppa
- source "extra/Configs/Config.hppa"
- endif
- if TARGET_i386
- source "extra/Configs/Config.i386"
- endif
- if TARGET_ia64
- source "extra/Configs/Config.ia64"
- endif
- if TARGET_lm32
- source "extra/Configs/Config.lm32"
- endif
- if TARGET_m68k
- source "extra/Configs/Config.m68k"
- endif
- if TARGET_metag
- source "extra/Configs/Config.metag"
- endif
- if TARGET_nds32
- source "extra/Configs/Config.nds32"
- endif
- if TARGET_nios2
- source "extra/Configs/Config.nios2"
- endif
- if TARGET_microblaze
- source "extra/Configs/Config.microblaze"
- endif
- if TARGET_mips
- source "extra/Configs/Config.mips"
- endif
- if TARGET_or1k
- source "extra/Configs/Config.or1k"
- endif
- if TARGET_powerpc
- source "extra/Configs/Config.powerpc"
- endif
- if TARGET_sh
- source "extra/Configs/Config.sh"
- endif
- if TARGET_sparc
- source "extra/Configs/Config.sparc"
- endif
- if TARGET_x86_64
- source "extra/Configs/Config.x86_64"
- endif
- if TARGET_xtensa
- source "extra/Configs/Config.xtensa"
- endif
- if TARGET_c6x
- source "extra/Configs/Config.c6x"
- endif
- if TARGET_arc
- source "extra/Configs/Config.arc"
- endif
- config TARGET_SUBARCH
- string
- default "e500" if CONFIG_E500
- default "classic" if CONFIG_CLASSIC
- default "sh4" if CONFIG_SH4
- default "sh4" if CONFIG_SH4A
- default "" if CONFIG_386
- default "i486" if CONFIG_486
- default "i586" if CONFIG_586
- default "i686" if CONFIG_686
- default "arcv2" if CONFIG_ARC_CPU_HS
- default ""
- source "extra/Configs/Config.in.arch"
- endmenu
- menu "General Library Settings"
- config HAVE_NO_PIC
- bool
- config DOPIC
- bool "Generate only Position Independent Code (PIC)"
- default y
- depends on !HAVE_NO_PIC
- help
- If you wish to build all of uClibc as PIC objects, then answer Y here.
- If you are unsure, then you should answer N.
- config ARCH_HAS_NO_SHARED
- bool
- config ARCH_HAS_NO_LDSO
- bool
- select ARCH_HAS_NO_SHARED
- config ARCH_HAS_UCONTEXT
- bool
- config HAVE_SHARED
- bool "Enable shared libraries"
- depends on !ARCH_HAS_NO_SHARED
- default y
- help
- If you wish to build uClibc with support for shared libraries then
- answer Y here. If you only want to build uClibc as a static library,
- then answer N.
- config FORCE_SHAREABLE_TEXT_SEGMENTS
- bool "Only load shared libraries which can share their text segment"
- depends on HAVE_SHARED
- select DOPIC
- help
- If you answer Y here, the uClibc native shared library loader will
- only load shared libraries, which do not need to modify any
- non-writable segments. These libraries haven't set the DT_TEXTREL
- tag in the dynamic section (==> objdump).
- All your libraries must be compiled with -fPIC or -fpic, and all
- assembler function must be written as position independent code (PIC).
- Enabling this option will make uClibc's shared library loader a
- little bit smaller and guarantee that no memory will be wasted by
- badly coded shared libraries.
- config LDSO_LDD_SUPPORT
- bool "Native 'ldd' support"
- depends on HAVE_SHARED
- default y
- help
- Enable all the code needed to support traditional ldd,
- which executes the shared library loader to resolve all dependencies
- and then provide a list of shared libraries that are required for an
- application to function. Disabling this option will make uClibc's
- shared library loader a little bit smaller.
- Most people will answer Y.
- config LDSO_CACHE_SUPPORT
- bool "Enable library loader cache (ld.so.conf)"
- depends on HAVE_SHARED
- default y
- help
- Enable this to make use of /etc/ld.so.conf, the shared library loader
- cache configuration file to support for non-standard library paths.
- After updating this file, it is necessary to run 'ldconfig' to update
- the /etc/ld.so.cache shared library loader cache file.
- config LDSO_PRELOAD_ENV_SUPPORT
- bool "Enable library loader LD_PRELOAD environment"
- depends on HAVE_SHARED
- default y
- help
- Enable this to make use of LD_PRELOAD environment variable.
- A whitespace-separated list of additional, user-specified, ELF shared
- libraries to be loaded before all others. This can be used to
- selectively override functions in other shared libraries. For
- set-user-ID/set-group-ID ELF binaries, only libraries in the standard
- search directories that are also set-user-ID will be loaded.
- config LDSO_PRELOAD_FILE_SUPPORT
- bool "Enable library loader preload file (ld.so.preload)"
- depends on HAVE_SHARED
- help
- Enable this to make use of /etc/ld.so.preload. This file contains a
- whitespace separated list of shared libraries to be loaded before
- the program.
- config LDSO_BASE_FILENAME
- string "Shared library loader naming prefix"
- depends on HAVE_SHARED && (LDSO_CACHE_SUPPORT || LDSO_PRELOAD_FILE_SUPPORT)
- default "ld.so"
- help
- If you wish to support both uClibc and glibc on the same system, it
- is necessary to set this to something other than "ld.so" to avoid
- conflicts with glibc, which also uses "ld.so". This prevents both
- libraries from using the same /etc/ld.so.* files. If you wish to
- support both uClibc and glibc on the same system then you should set
- this to "ld-uClibc.so".
- Most people will leave this set to the default of "ld.so".
- WARNING: Changing the default prefix could cause problems with
- binutils' ld !
- config LDSO_STANDALONE_SUPPORT
- bool "Dynamic linker stand-alone mode support"
- depends on HAVE_SHARED
- help
- The dynamic linker can be run either indirectly through running some
- dynamically linked program or library (in which case no command line
- options to the dynamic linker can be passed and, in the ELF case, the
- dynamic linker which is stored in the .interp section of the program
- is executed) or directly by running:
- /lib/ld-uClibc.so.* [OPTIONS] [PROGRAM [ARGUMENTS]]
- Stand-alone execution is a prerequisite for adding prelink
- capabilities to uClibc dynamic linker, as well useful for testing an
- updated version of the dynamic linker without breaking the system.
- config LDSO_PRELINK_SUPPORT
- bool "Dynamic linker prelink support"
- depends on HAVE_SHARED
- select LDSO_STANDALONE_SUPPORT
- help
- The dynamic linker can be used in stand-alone mode by the prelink tool
- for prelinking ELF shared libraries and binaries to speed up startup
- time. It also is able to load and handle prelinked libraries and
- binaries at runtime.
- config UCLIBC_STATIC_LDCONFIG
- bool "Link ldconfig statically"
- depends on HAVE_SHARED
- default y
- help
- Enable this option to statically link the ldconfig binary.
- Making ldconfig static can be beneficial if you have a library
- problem and need to use ldconfig to recover. Sometimes it is
- preferable to instead keep the size of the system down, in which
- case you should disable this option.
- config LDSO_RUNPATH
- bool "Enable ELF RUNPATH tag support"
- depends on HAVE_SHARED
- default y if LDSO_CACHE_SUPPORT
- help
- ELF's may have dynamic RPATH/RUNPATH tags. These tags list paths
- which extend the library search paths. They are really only useful
- if a package installs libraries in non standard locations and
- ld.so.conf support is disabled.
- Usage of RUNPATH tags is not too common, so disabling this feature
- should be safe for most people.
- config LDSO_RUNPATH_OF_EXECUTABLE
- bool "Use executables RUNPATH/RPATH when searching for libraries."
- depends on LDSO_RUNPATH
- default n
- help
- Use the executables RUNPATH/RPATH to find to find libraries even
- though this behavour is not standard. Setting this option causes
- the uclibc dynamic linker behavour to match the glibc dynamic linker.
- config LDSO_SAFE_RUNPATH
- bool "Allow only RUNPATH beginning with /"
- depends on LDSO_RUNPATH
- default y
- help
- Allow only absolute path in RPATH/RUNPATH.
- config LDSO_SEARCH_INTERP_PATH
- bool "Add ldso path to lib search path"
- depends on HAVE_SHARED
- default y
- help
- The ldso is told where it is being executed from and can use that
- path to find related core libraries. This is useful by default,
- but can be annoying in a mixed development environment.
- i.e. if the ldso is run from /foo/boo/ldso.so, it will start its
- library search with /foo/boo/
- If unsure, simply say Y here.
- config LDSO_LD_LIBRARY_PATH
- bool "Add LD_LIBRARY_PATH to lib search path"
- depends on HAVE_SHARED
- default y
- help
- On hardened system it could be useful to disable the use of
- LD_LIBRARY_PATH environment variable (a colon-separated list of
- directories in which to search for ELF libraries at execution-time).
- If unsure, simply say Y here.
- config LDSO_NO_CLEANUP
- bool "Disable automatic unloading of dynamically loaded shared objects"
- depends on HAVE_SHARED
- help
- If you need complete allocation traces when debugging memory leaks
- using Valgrind in a process that dynamically loads shared objects,
- then answer Y here. Unlike glibc, uClibc unloads all dynamically
- loaded shared objects when a process exits, which prevents Valgrind
- from correctly resolving the symbols from the unloaded shared objects.
- Unless you know you need this, you should answer N.
- config UCLIBC_CTOR_DTOR
- bool
- default y
- help
- If you wish to build uClibc with support for global constructor
- (ctor) and global destructor (dtor) support, then answer Y here.
- When ctor/dtor support is enabled, binaries linked with uClibc must
- also be linked with crtbegin.o and crtend.o which are provided by gcc
- (the "*startfile:" and "*endfile:" settings in your gcc specs file
- may need to be adjusted to include these files). This support will
- also add a small amount of additional size to each binary compiled vs
- uClibc. If you will be using uClibc with C++, or if you need the gcc
- __attribute__((constructor)) and __attribute__((destructor)) to work,
- then you definitely want to answer Y here. If you don't need ctors
- or dtors and want your binaries to be as small as possible, then
- answer N.
- config LDSO_GNU_HASH_SUPPORT
- bool "Enable GNU hash style support"
- depends on HAVE_SHARED
- help
- Newest binutils support a new hash style named GNU-hash. The dynamic
- linker will use the new GNU-hash section (.gnu.hash) for symbol lookup
- if present into the ELF binaries, otherwise it will use the old SysV
- hash style (.hash). This ensures that it is completely backward
- compatible.
- Further, being the hash table implementation self-contained into each
- executable and shared libraries, objects with mixed hash style can
- peacefully coexist in the same process.
- If you want to use this new feature, answer Y
- choice
- prompt "Thread support"
- default HAS_NO_THREADS
- help
- If you want to compile uClibc with pthread support, then answer Y.
- This will increase the size of uClibc by adding a bunch of locking
- to critical data structures, and adding extra code to ensure that
- functions are properly reentrant.
- config HAS_NO_THREADS
- bool "none"
- help
- Disable thread support.
- config UCLIBC_HAS_LINUXTHREADS
- bool "Linuxthreads"
- # linuxthreads need nanosleep()
- select UCLIBC_HAS_REALTIME
- depends on !TARGET_metag
- help
- If you want to compile uClibc with Linuxthreads support, then answer Y.
- config UCLIBC_HAS_THREADS_NATIVE
- bool "Native POSIX Threading (NPTL)"
- select UCLIBC_HAS_TLS
- select UCLIBC_HAS_STDIO_FUTEXES
- select UCLIBC_HAS_REALTIME
- # i386 has no lowlevellock support (yet) as opposed to i486 onward
- depends on !CONFIG_386 && \
- !TARGET_alpha && \
- !TARGET_avr32 && \
- !TARGET_bfin && \
- !TARGET_c6x && \
- !TARGET_cris && \
- !TARGET_frv && \
- !TARGET_h8300 && \
- !TARGET_hppa && \
- !TARGET_ia64 && \
- !TARGET_m68k && \
- !TARGET_nds32 && \
- !TARGET_or1k && \
- ARCH_USE_MMU
- help
- If you want to compile uClibc with NPTL support, then answer Y.
- endchoice
- config UCLIBC_HAS_THREADS
- def_bool y if !HAS_NO_THREADS
- config UCLIBC_HAS_TLS
- bool "Thread-Local Storage"
- depends on UCLIBC_HAS_THREADS_NATIVE
- help
- If you want to enable TLS support then answer Y.
- This is fast an efficient way to store per-thread local data
- which is not on stack. It needs __thread support enabled in
- gcc.
- config PTHREADS_DEBUG_SUPPORT
- bool "Build pthreads debugging support"
- depends on UCLIBC_HAS_THREADS
- help
- Say Y here if you wish to be able to debug applications that use
- uClibc's pthreads library. By enabling this option, a library
- named libthread_db will be built. This library will be dlopen()'d
- by gdb and will allow gdb to debug the threads in your application.
- IMPORTANT NOTE! Because gdb must dlopen() the libthread_db library,
- you must compile gdb with uClibc in order for pthread debugging to
- work properly.
- If you are doing development and want to debug applications using
- uClibc's pthread library, answer Y. Otherwise, answer N.
- config UCLIBC_HAS_SYSLOG
- bool "Syslog support"
- default y
- depends on UCLIBC_HAS_NETWORK_SUPPORT
- select UCLIBC_HAS_SOCKET
- help
- Support sending messages to the system logger.
- This requires socket-support.
- choice
- prompt "Malloc Implementation"
- default MALLOC if ! ARCH_USE_MMU
- default MALLOC_STANDARD if ARCH_USE_MMU
- config MALLOC
- bool "malloc"
- help
- "malloc" use mmap for all allocations and so works very well on
- MMU-less systems that do not support the brk() system call. It is
- pretty smart about reusing already allocated memory, and minimizing
- memory wastage.
- This is the default for uClinux MMU-less systems.
- config MALLOC_SIMPLE
- bool "malloc-simple"
- help
- "malloc-simple" is trivially simple and slow as molasses. It
- was written from scratch for uClibc, and is the simplest possible
- (and therefore smallest) malloc implementation.
- This uses only the mmap() system call to allocate and free memory,
- and does not use the brk() system call at all, making it a fine
- choice for MMU-less systems with very limited memory. It's 100%
- standards compliant, thread safe, very small, and releases freed
- memory back to the OS immediately rather than keeping it in the
- process's heap for reallocation. It is also VERY SLOW.
- config MALLOC_STANDARD
- bool "malloc-standard"
- depends on ARCH_USE_MMU
- help
- "malloc-standard" is derived from the public domain dlmalloc
- implementation by Doug Lea. It is quite fast, and is pretty smart
- about reusing already allocated memory, and minimizing memory
- wastage. This uses brk() for small allocations, while using mmap()
- for larger allocations. This is the default malloc implementation
- for uClibc.
- If unsure, answer "malloc-standard".
- endchoice
- config UCLIBC_DYNAMIC_ATEXIT
- bool "Dynamic atexit() Support"
- default y
- help
- When this option is enabled, uClibc will support an infinite number,
- of atexit() and on_exit() functions, limited only by your available
- memory. This can be important when uClibc is used with C++, since
- global destructors are implemented via atexit(), and it is quite
- possible to exceed the default number when this option is disabled.
- Enabling this option adds a few bytes, and more significantly makes
- atexit and on_exit depend on malloc, which can be bad when compiling
- static executables.
- Unless you use uClibc with C++, you should probably answer N.
- config COMPAT_ATEXIT
- bool "Old (visible) atexit Support"
- help
- Enable this option if you want to update from 0.9.28 to git/0.9.29,
- else you will be missing atexit() until you rebuild all apps.
- config UCLIBC_HAS_UTMPX
- bool "utmpx based support for tracking login/logouts to/from the system"
- help
- Answer y to enable support for accessing user accounting database.
- It can be used to track all login/logout to the system.
- config UCLIBC_HAS_UTMP
- bool "utmp support (XPG2 compat, SVr4 compat)"
- depends on UCLIBC_HAS_UTMPX
- help
- Answer y to enable legacy SVID support for accessing
- user accounting database:
- getutent(), getutid(), getutline(), pututline(),
- setutent(), endutent(), utmpname() in utmp.h
- It can be used to track all login/logout to the system.
- If unsure, answer N and use corresponding POSIX functions
- from utmpx.h
- config UCLIBC_SUSV2_LEGACY
- bool "Enable SuSv2 LEGACY functions"
- help
- Enable this option if you want to have SuSv2 LEGACY functions
- Currently applies to:
- valloc
- WARNING! ABI incompatibility.
- config UCLIBC_SUSV3_LEGACY
- bool "Enable SuSv3 LEGACY functions"
- #vfork,
- # h_errno
- # gethostbyaddr
- # gethostbyname
- help
- Enable this option if you want to have SuSv3 LEGACY functions
- in the library, else they are replaced by SuSv3 proposed macros.
- Currently applies to:
- bcmp, bcopy, bzero, index, rindex, ftime,
- bsd_signal, (ecvt), (fcvt), gcvt, (getcontext),
- (getwd), (makecontext),
- mktemp, (pthread_attr_getstackaddr), (pthread_attr_setstackaddr),
- scalb, (setcontext), (swapcontext), ualarm, usleep,
- wcswcs.
- WARNING! ABI incompatibility.
- config UCLIBC_HAS_CONTEXT_FUNCS
- bool "Use obsolescent context control functions"
- depends on UCLIBC_SUSV3_LEGACY && ARCH_HAS_UCONTEXT
- help
- Add into library the SuSv3 obsolescent functions used for context
- control. The setcontext family allows the implementation in C of
- advanced control flow patterns such as iterators, fibers, and
- coroutines. They may be viewed as an advanced version of
- setjmp/longjmp; whereas the latter allows only a single non-local jump
- up the stack, setcontext allows the creation of multiple cooperative
- threads of control, each with its own stack.
- These functions are: setcontext, getcontext, makecontext, swapcontext.
- config UCLIBC_SUSV3_LEGACY_MACROS
- bool "Enable SuSv3 LEGACY macros"
- help
- Enable this option if you want to have SuSv3 LEGACY macros.
- Currently applies to bcopy/bzero/bcmp/index/rindex et al.
- WARNING! ABI incompatibility.
- config UCLIBC_SUSV4_LEGACY
- bool "Enable SuSv4 LEGACY or obsolescent functions"
- help
- Enable this option if you want to have SuSv4 LEGACY functions
- and macros in the library.
- Currently applies to:
- - XSI functions:
- _longjmp, _setjmp, _tolower, _toupper, ftw, getitimer,
- gettimeofday, isascii, pthread_getconcurrency,
- pthread_setconcurrency, setitimer, setpgrp, sighold,
- sigignore, sigpause, sigrelse, sigset, siginterrupt,
- tempnam, toascii, ulimit.
- - Base functions:
- asctime, asctime_r, ctime, ctime_r, gets, rand_r,
- tmpnam, utime.
- WARNING! ABI incompatibility.
- config UCLIBC_STRICT_HEADERS
- bool "Hide structures and constants for unsupported features"
- help
- Hide structures and constants in headers that should not be used,
- because the respective feature is disabled.
- WARNING! enabling this option requires to patch many faulty apps,
- since they make (wrongly) use of these structures/constants,
- although the feature was disabled.
- config UCLIBC_HAS_STUBS
- bool "Provide stubs for unavailable functionality"
- help
- With this option uClibc provides non-functional stubs for
- functions which are impossible to implement on the target
- architecture. Otherwise, such functions are simply omitted.
- config UCLIBC_HAS_SHADOW
- bool "Shadow Password Support"
- default y
- help
- Answer N if you do not need shadow password support.
- Most people will answer Y.
- config UCLIBC_HAS_PROGRAM_INVOCATION_NAME
- bool "Support for program_invocation_name"
- help
- Support for the GNU-specific program_invocation_name and
- program_invocation_short_name strings. Some GNU packages
- (like tar and coreutils) utilize these for extra useful
- output, but in general are not required.
- At startup, these external strings are automatically set
- up based on the value of ARGV[0].
- If unsure, just answer N.
- config UCLIBC_HAS___PROGNAME
- bool "Support for __progname"
- default y
- help
- Some packages (like openssh) like to peek into internal libc
- symbols to make their output a bit more user friendly.
- At startup, __progname is automatically set up based on the
- value of ARGV[0].
- If unsure, just answer N.
- config UCLIBC_HAS_PTY
- bool "Support for pseudo-terminals"
- default y
- help
- This enables support for pseudo-terminals (see man 4 pts
- and man 7 pty).
- If unsure, just answer Y.
- config ASSUME_DEVPTS
- bool "Assume that /dev/pts is a devpts or devfs file system"
- default y
- depends on UCLIBC_HAS_PTY
- help
- Enable this if /dev/pts is on a devpts or devfs filesystem. Both
- these filesystems automatically manage permissions on the /dev/pts
- devices. You may need to mount your devpts or devfs filesystem on
- /dev/pts for this to work.
- Most people should answer Y.
- config UNIX98PTY_ONLY
- bool "Support only Unix 98 PTYs"
- default y
- depends on UCLIBC_HAS_PTY
- help
- If you want to support only Unix 98 PTYs enable this. Some older
- applications may need this disabled and will thus use legacy BSD
- style PTY handling which is more complex and also bigger than
- Unix 98 PTY handling.
- For most current programs, you can generally answer Y.
- if UNIX98PTY_ONLY
- config UCLIBC_HAS_GETPT
- bool "Support getpt() (glibc-compat)"
- depends on UCLIBC_HAS_PTY
- help
- Some packages may need getpt().
- All of those are non-standard and can be considered
- GNU/libc compatibility.
- Either use posix_openpt() or just open /dev/ptmx yourself.
- If unsure, just say N.
- endif
- if !UNIX98PTY_ONLY
- # Have to use __libc_ptyname{1,2}[] and related bloat
- config UCLIBC_HAS_GETPT
- def_bool y
- endif
- config UCLIBC_HAS_LIBUTIL
- bool "Provide libutil library and functions"
- depends on UCLIBC_HAS_PTY
- help
- Provide a libutil library.
- This non-standard conforming library provides the following
- utility functions:
- forkpty(): combines openpty(), fork(2), and login_tty() to
- create a new process operating in a pseudo-terminal.
- login(): write utmp and wtmp entries
- login_tty(): prepares for a login on the tty fd by creating a
- new session, making fd the controlling terminal for
- the calling process, setting fd to be the standard
- input, output, and error streams of the current
- process, and closing fd.
- logout(): write utmp and wtmp entries
- logwtmp(): constructs a utmp structure and calls updwtmp() to
- append the structure to the utmp file.
- openpty(): finds an available pseudo-terminal and returns
- file descriptors for the master and slave
- This library adds about 3k-4k to your system.
- config UCLIBC_HAS_TM_EXTENSIONS
- bool "Support 'struct tm' timezone extension fields"
- default y
- help
- Enabling this option adds fields to 'struct tm' in time.h for
- tracking the number of seconds east of UTC, and an abbreviation for
- the current timezone. These fields are not specified by the SuSv3
- standard, but they are commonly used in both GNU and BSD application
- code.
- To strictly follow the SuSv3 standard, leave this disabled.
- Most people will probably want to answer Y.
- config UCLIBC_HAS_TZ_CACHING
- bool "Enable caching of the last valid timezone 'TZ' string"
- default y
- help
- Answer Y to enable caching of the last valid 'TZ' string describing
- the timezone setting. This allows a quick string compare to avoid
- repeated parsing of unchanged 'TZ' strings when tzset() is called.
- Most people will answer Y.
- config UCLIBC_HAS_TZ_FILE
- bool "Enable '/etc/TZ' file support to set a default timezone (uClibc-specific)"
- default y
- help
- Answer Y to enable the setting of a default timezone for uClibc.
- Ordinarily, uClibc gets the timezone information exclusively from the
- 'TZ' environment variable. In particular, there is no support for
- the zoneinfo directory tree or the /etc/timezone file used by glibc.
- With this option enabled, uClibc will use the value stored in the
- file '/etc/TZ' (default path) to obtain timezone information if the
- 'TZ' environment variable is missing or has an invalid value. The
- file consists of a single line (newline required) of text describing
- the timezone in the format specified for the TZ environment variable.
- Doing 'echo CST6CDT > /etc/TZ' is enough to create a valid file.
- See
- http://www.opengroup.org/onlinepubs/007904975/basedefs/xbd_chap08.html
- for details on valid settings of 'TZ'.
- Most people will answer Y.
- config UCLIBC_HAS_TZ_FILE_READ_MANY
- bool "Repeatedly read the '/etc/TZ' file"
- depends on UCLIBC_HAS_TZ_FILE
- default y
- help
- Answer Y to enable repeated reading of the '/etc/TZ' file even after
- a valid value has been read. This incurs the overhead of an
- open/read/close for each tzset() call (explicit or implied). However,
- setting this will allow applications to update their timezone
- information if the contents of the file change.
- Most people will answer Y.
- config UCLIBC_TZ_FILE_PATH
- string "Path to the 'TZ' file for setting the global timezone"
- depends on UCLIBC_HAS_TZ_FILE
- default "/etc/TZ"
- help
- This is the path to the 'TZ' file.
- Most people will use the default of '/etc/TZ'.
- config UCLIBC_FALLBACK_TO_ETC_LOCALTIME
- bool "Use /etc/localtime as a fallback"
- depends on UCLIBC_HAS_TZ_FILE
- default y
- help
- Answer Y to try to use /etc/localtime file.
- On glibc systems this file (if it is in TZif2 format)
- contains timezone string at the end.
- Most people will answer Y.
- endmenu
- menu "Advanced Library Settings"
- config UCLIBC_PWD_BUFFER_SIZE
- int "Buffer size for getpwnam() and friends"
- default 256
- range 12 1024
- help
- This sets the value of the buffer size for getpwnam() and friends.
- By default, this is 256. (For reference, glibc uses 1024).
- The value can be found using sysconf() with the _SC_GETPW_R_SIZE_MAX
- parameter.
- config UCLIBC_GRP_BUFFER_SIZE
- int "Buffer size for getgrnam() and friends"
- default 256
- range 12 1024
- help
- This sets the value of the buffer size for getgrnam() and friends.
- By default, this is 256. (For reference, glibc uses 1024).
- The value can be found using sysconf() with the _SC_GETGR_R_SIZE_MAX
- parameter.
- comment "Support various families of functions"
- config UCLIBC_LINUX_SPECIFIC
- bool "Linux specific functions"
- default y
- help
- accept4(), bdflush(),
- capget(), capset(), eventfd(), fallocate(),
- fstatfs(), getrandom(), inotify_*(), ioperm(), iopl(),
- madvise(), modify_ldt(), pipe2(), personality(),
- prctl()/arch_prctl(), pivot_root(), modify_ldt(),
- ppoll(), readahead(), reboot(), remap_file_pages(),
- sched_getaffinity(), sched_setaffinity(), sendfile(),
- setfsgid(), setfsuid(), setresgid(), setresuid(),
- splice(), vmsplice(), tee(), signalfd(), statfs(),
- swapoff(), swapon(), sync_file_range(), syncfs(),
- _sysctl(), sysinfo(), timerfd_*(), vhangup(), umount(),
- umount2()
- config UCLIBC_HAS_GNU_ERROR
- bool "Support GNU extensions for error-reporting"
- default y
- help
- Support for the GNU-specific error(), error_at_line(),
- void (* error_print_progname)(), error_message_count
- functions and variables. Some GNU packages
- utilize these for extra useful output, but in general
- are not required.
- If unsure, just answer N.
- config UCLIBC_BSD_SPECIFIC
- bool "BSD specific functions"
- default y
- help
- mincore(), getdomainname(), setdomainname()
- If unsure, say N.
- config UCLIBC_HAS_BSD_ERR
- bool "BSD err functions"
- default y
- help
- These functions are non-standard BSD extensions.
- err(), errx(), warn(), warnx(), verr(), verrx(), vwarn(), vwarnx()
- If unsure, say N.
- config UCLIBC_HAS_OBSOLETE_BSD_SIGNAL
- bool "BSD obsolete signal functions"
- help
- These functions are provided as a compatibility interface for
- programs that make use of the historical System V signal API.
- This API is obsolete:
- new applications should use the POSIX signal API (sigaction(2),
- sigprocmask(2), etc.).
- Affected functions:
- sigset(), sighold(), sigrelse(), sigignore()
- If unsure, say N.
- config UCLIBC_HAS_OBSOLETE_SYSV_SIGNAL
- bool "SYSV obsolete signal functions"
- help
- Use of sysv_signal() should be avoided; use sigaction(2) instead.
- If unsure, say N.
- config UCLIBC_NTP_LEGACY
- bool "ntp_*() aliases"
- help
- Provide legacy aliases for ntp functions:
- ntp_adjtime(), ntp_gettime()
- It is safe to say N here.
- config UCLIBC_SV4_DEPRECATED
- bool "Enable SVr4 deprecated functions"
- help
- These functions are DEPRECATED in System V release 4.
- Say N unless you desparately need one of the functions below:
- ustat() [use statfs(2) in your code instead]
- config UCLIBC_HAS_REALTIME
- bool "Realtime-related family of SUSv functions"
- default y
- help
- These functions are part of the Timers option and need not
- be available on all implementations.
- Includes AIO, message-queue, scheduler, semaphore functions:
- aio.h
- mqueue.h
- sched.h
- semaphore.h
- aio_cancel()
- aio_error()
- aio_fsync()
- aio_read()
- lio_listio()
- aio_return()
- aio_suspend()
- aio_write()
- clock_getres(), clock_gettime(), clock_settime()
- fdatasync()
- mlockall(), munlockall()
- mlock(), munlock()
- mq_close()
- mq_getattr()
- mq_notify()
- mq_open()
- mq_receive()
- mq_send()
- mq_setattr()
- mq_unlink()
- nanosleep()
- sched_getparam()
- sched_get_priority_max(), sched_get_priority_min()
- sched_getscheduler()
- sched_rr_get_interval()
- sched_setparam()
- sched_setscheduler()
- sem_close()
- sem_destroy()
- sem_getvalue()
- sem_init()
- sem_open()
- sem_post()
- sem_trywait(), sem_wait()
- sem_unlink()
- sigqueue()
- sigtimedwait(), sigwaitinfo()
- timer_create()
- timer_delete()
- timer_getoverrun(), timer_gettime(), timer_settime()
- config UCLIBC_HAS_ADVANCED_REALTIME
- bool "Advanced realtime-related family of SUSv functions"
- default y
- depends on UCLIBC_HAS_REALTIME
- help
- These functions are part of the Timers option and need not
- be available on all implementations.
- clock_getcpuclockid()
- clock_nanosleep()
- mq_timedreceive()
- mq_timedsend()
- posix_fadvise()
- posix_fallocate()
- posix_madvise()
- posix_memalign()
- posix_mem_offset()
- posix_spawnattr_destroy(), posix_spawnattr_init()
- posix_spawnattr_getflags(), posix_spawnattr_setflags()
- posix_spawnattr_getpgroup(), posix_spawnattr_setpgroup()
- posix_spawnattr_getschedparam(), posix_spawnattr_setschedparam()
- posix_spawnattr_getschedpolicy(), posix_spawnattr_setschedpolicy()
- posix_spawnattr_getsigdefault(), posix_spawnattr_setsigdefault()
- posix_spawnattr_getsigmask(), posix_spawnattr_setsigmask()
- posix_spawn_file_actions_addclose()
- posix_spawn_file_actions_adddup2()
- posix_spawn_file_actions_addopen()
- posix_spawn_file_actions_destroy()
- posix_spawn_file_actions_init()
- posix_spawn()
- posix_spawnp()
- posix_typed_mem_get_info()
- pthread_mutex_timedlock()
- sem_timedwait()
- #config UCLIBC_HAS_TERMIOS
- # bool "termios functions"
- # default y
- # help
- # Get and set terminal attributes, line control, get and set baud
- # rate.
- # termios(), tcgetattr(), tcsetattr(), tcsendbreak(), tcdrain(),
- # tcflush(), tcflow(), cfmakeraw(), cfgetospeed(), cfgetispeed(),
- # cfsetispeed(), cfsetospeed(), cfsetspeed()
- #
- # If unsure, say Y.
- config UCLIBC_HAS_EPOLL
- bool "epoll"
- default y
- help
- epoll_create(), epoll_ctl(), epoll_wait() functions.
- config UCLIBC_HAS_XATTR
- bool "Extended Attributes"
- default y
- help
- Extended Attributes support.
- setxattr()
- lsetxattr()
- fsetxattr()
- getxattr()
- lgetxattr()
- fgetxattr()
- listxattr()
- llistxattr()
- flistxattr()
- removexattr()
- lremovexattr()
- fremovexattr()
- Say N unless you need support for extended attributes and the
- filesystems do actually support them.
- config UCLIBC_HAS_PROFILING
- bool "Profiling support"
- default y
- help
- gcc's -finstrument-functions needs these.
- Most people can safely answer N.
- config UCLIBC_HAS_CRYPT_IMPL
- bool "libcrypt support"
- default y
- help
- libcrypt contains crypt(), setkey() and encrypt()
- config UCLIBC_HAS_SHA256_CRYPT_IMPL
- bool "libcrypt SHA256 support"
- depends on UCLIBC_HAS_CRYPT_IMPL
- help
- This adds support for SHA256 password hashing via the crypt() function.
- Say N here if you do not need SHA256 crypt support.
- config UCLIBC_HAS_SHA512_CRYPT_IMPL
- bool "libcrypt SHA512 support"
- depends on UCLIBC_HAS_CRYPT_IMPL
- help
- This adds support for SHA512 password hashing via the crypt() function.
- Say N here if you do not need SHA512 crypt support.
- config UCLIBC_HAS_CRYPT_STUB
- bool "libcrypt stubs"
- default y
- depends on !UCLIBC_HAS_CRYPT_IMPL
- help
- Standards mandate that crypt(3) provides a stub if it is unavailable.
- If you enable this option then stubs for
- crypt(), setkey() and encrypt()
- will be provided in a small libcrypt.
- config UCLIBC_HAS_CRYPT
- def_bool y
- depends on UCLIBC_HAS_CRYPT_IMPL || UCLIBC_HAS_CRYPT_STUB
- endmenu
- menuconfig UCLIBC_HAS_NETWORK_SUPPORT
- bool "Networking Support"
- default y
- help
- Say N here if you do not need network support.
- if UCLIBC_HAS_NETWORK_SUPPORT
- config UCLIBC_HAS_SOCKET
- bool "Socket support"
- default y
- help
- If you want to include support for sockets then answer Y.
- config UCLIBC_HAS_IPV4
- bool "IP version 4 support"
- default y
- select UCLIBC_HAS_SOCKET
- help
- If you want to include support for the Internet Protocol
- (IP version 4) then answer Y.
- Most people will say Y.
- config UCLIBC_HAS_IPV6
- bool "IP version 6 support"
- select UCLIBC_HAS_SOCKET
- help
- If you want to include support for the next version of the Internet
- Protocol (IP version 6) then answer Y.
- Most people should answer N.
- config UCLIBC_HAS_RPC
- bool "Remote Procedure Call (RPC) support"
- # RPC+socket-ipvX doesn't currently work.
- depends on UCLIBC_HAS_IPV4 || UCLIBC_HAS_IPV6
- help
- If you want to include RPC support, enable this. RPC is rarely used
- for anything except for the NFS filesystem. Unless you plan to use
- NFS, you can probably leave this set to N and save some space.
- If you need to use NFS then you should answer Y.
- config UCLIBC_HAS_FULL_RPC
- bool "Full RPC support"
- depends on UCLIBC_HAS_RPC
- default y if !HAVE_SHARED
- help
- Normally we enable just enough RPC support for things like rshd and
- nfs mounts to work. If you find you need the rest of the RPC stuff,
- then enable this option. Most people can safely answer N.
- config UCLIBC_HAS_REENTRANT_RPC
- bool "Reentrant RPC support"
- depends on UCLIBC_HAS_RPC
- default y if !HAVE_SHARED
- help
- Most packages utilize the normal (non-reentrant) RPC functions, but
- some (like exportfs from nfs-utils) need these reentrant versions.
- Most people can safely answer N.
- config UCLIBC_USE_NETLINK
- bool "Use netlink to query interfaces"
- depends on UCLIBC_HAS_SOCKET
- help
- In newer versions of Linux (2.4.17+), support was added for querying
- network device information via netlink rather than the old style
- ioctl's. Most of the time, the older ioctl style is sufficient (and
- it is smaller than netlink), but if you find that not all of your
- devices are being returned by the if_nameindex() function, you will
- have to use the netlink implementation.
- Most people can safely answer N.
- config UCLIBC_SUPPORT_AI_ADDRCONFIG
- bool "Support the AI_ADDRCONFIG flag"
- depends on UCLIBC_USE_NETLINK
- help
- The implementation of AI_ADDRCONFIG is aligned with the glibc
- implementation using netlink to query interfaces to find both
- ipv4 and ipv6 support. This is only needed if an application uses
- the AI_ADDRCONFIG flag.
- Most people can safely answer N.
- config UCLIBC_HAS_BSD_RES_CLOSE
- bool "Support res_close() (bsd-compat)"
- help
- Answer Y if you desperately want to support BSD compatibility in
- the network code.
- Most people will say N.
- config UCLIBC_HAS_COMPAT_RES_STATE
- bool "Use compatible but bloated _res"
- default y
- help
- Answer Y if you build network utilities and they muck with resolver
- internals a lot (_res global structure). uclibc does not use most
- of _res.XXX fields, and with this option OFF they won't even exist.
- Which will make e.g. dig build fail.
- Answering N saves around 400 bytes in bss.
- config UCLIBC_HAS_EXTRA_COMPAT_RES_STATE
- bool "Use extra compatible but extra bloated _res"
- help
- Answer Y if selecting UCLIBC_HAS_COMPAT_RES_STATE is not enough.
- As far as I can say, this should never be needed.
- config UCLIBC_HAS_RESOLVER_SUPPORT
- bool "DNS resolver functions"
- select UCLIBC_HAS_COMPAT_RES_STATE
- depends on UCLIBC_HAS_IPV4 || UCLIBC_HAS_IPV6
- help
- Provide implementations for DNS resolver functions.
- In particular, the following functions will be added to the
- library:
- ns_skiprr, ns_initparse, ns_parserr, ns_msg_getflag,
- res_mkquery, res_init, res_ninit, res_close, res_nclose
- res_query, res_search, res_querydomain,
- dn_expand, dn_comp,
- ns_name_uncompress, ns_name_ntop, ns_name_pton, ns_name_unpack,
- ns_name_pack, ns_name_compress, ns_name_skip, dn_skipname,
- ns_get16, ns_get32, ns_put16, ns_put32
- endif
- menu "String and Stdio Support"
- config UCLIBC_HAS_STRING_GENERIC_OPT
- bool "Use faster (but larger) generic string functions"
- default y
- help
- Answer Y to use the (tweaked) glibc generic string functions.
- In general, they are faster (but 3-5K larger) than the base
- uClibc string functions which are optimized solely for size.
- Many people will answer Y.
- config UCLIBC_HAS_STRING_ARCH_OPT
- bool "Use arch-specific assembly string functions (where available)"
- default y
- help
- Answer Y to use any archtecture-specific assembly language string
- functions available for this target plaform.
- Note that assembly implementations are not available for all string
- functions, so some generic (written in C) string functions may
- still be used.
- These are small and fast, the only reason _not_ to say Y here is
- for debugging purposes.
- config UCLIBC_HAS_STDIO_FUTEXES
- bool "Use futexes for multithreaded I/O locking"
- depends on UCLIBC_HAS_THREADS_NATIVE
- help
- If you want to compile uClibc to use futexes for low-level
- I/O locking, answer Y. Otherwise, answer N.
- config UCLIBC_HAS_CTYPE_TABLES
- bool "Use Table Versions Of 'ctype.h' Functions."
- default y
- help
- Answer Y to use table versions of the 'ctype.h' functions.
- While the non-table versions are often smaller when building
- statically linked apps, they work only in stub locale mode.
- Most people will answer Y.
- config UCLIBC_HAS_CTYPE_SIGNED
- bool "Support Signed Characters In 'ctype.h' Functions."
- depends on UCLIBC_HAS_CTYPE_TABLES
- default y
- help
- Answer Y to enable support for passing signed char values to
- the 'ctype.h' functions. ANSI/ISO C99 and SUSv3 specify that
- these functions are only defined for unsigned char values and
- EOF. However, glibc allows negative signed char values as well
- in order to support 'broken old programs'.
- Most people will answer Y.
- choice
- prompt "ctype argument checking"
- depends on UCLIBC_HAS_CTYPE_TABLES
- default UCLIBC_HAS_CTYPE_UNSAFE
- help
- Please select the invalid arg behavior you want for the 'ctype'
- functions.
- The 'ctype' functions are now implemented using table lookups, with
- the arg being the index. This can result in incorrect memory accesses
- or even segfaults for args outside of the allowed range.
- NOTE: This only affects the 'ctype' _functions_. It does not affect
- the macro implementations.
- config UCLIBC_HAS_CTYPE_UNSAFE
- bool "Do not check -- unsafe"
- config UCLIBC_HAS_CTYPE_CHECKED
- bool "Detect and handle appropriately"
- config UCLIBC_HAS_CTYPE_ENFORCED
- bool "Issue a diagnostic and abort()"
- endchoice
- config UCLIBC_HAS_WCHAR
- bool "Wide Character Support"
- help
- Answer Y to enable wide character support. This will make uClibc
- much larger. It is also currently required for locale support.
- Most people will answer N.
- config UCLIBC_HAS_LIBICONV
- bool "Iconv Support"
- help
- Add tiny iconv support for charset conversion from and to UTF-8.
- config UCLIBC_HAS_LIBINTL
- bool "Intl stubs support"
- help
- If you enable this option you get stubs for the gettext family of
- functions.
- config UCLIBC_HAS_LOCALE
- bool "Locale Support"
- select UCLIBC_HAS_WCHAR
- select UCLIBC_HAS_CTYPE_TABLES
- select UCLIBC_HAS_LIBICONV
- help
- uClibc now has full ANSI/ISO C99 locale support (except for
- wcsftime() and collating items in regex). Be aware that enabling
- this option will make uClibc much larger.
- Enabling UCLIBC_HAS_LOCALE with the default set of supported locales
- (169 UTF-8 locales, and 144 locales for other codesets) will enlarge
- uClibc by around 300k. You can reduce this size by building your own
- custom set of locate data (see extra/locale/LOCALES for details).
- uClibc's locale support is still under development. For example,
- codesets using shift states are not currently supported. Support is
- planned in the next iteration of locale support.
- Answer Y to enable locale support. Most people will answer N.
- choice
- prompt "Locale data"
- depends on UCLIBC_HAS_LOCALE
- default UCLIBC_BUILD_MINIMAL_LOCALE
- config UCLIBC_BUILD_MINIMAL_LOCALE
- bool "Only selected locales"
- depends on UCLIBC_HAS_LOCALE
- help
- If you do not need all locales that are available on your
- host-box, then set this to 'Y'.
- config UCLIBC_BUILD_ALL_LOCALE
- bool "All locales"
- depends on UCLIBC_HAS_LOCALE
- help
- This builds all the locales that are available on your
- host-box.
- endchoice
- config UCLIBC_BUILD_MINIMAL_LOCALES
- string "locales to use"
- depends on UCLIBC_BUILD_MINIMAL_LOCALE
- default "en_US"
- help
- Space separated list of locales to use.
- E.g.:
- en_US en_GB de_AT
- default:
- en_US
- config UCLIBC_HAS_XLOCALE
- bool "Extended Locale Support (experimental/incomplete)"
- depends on UCLIBC_HAS_LOCALE
- help
- Answer Y to enable extended locale support similar to that provided
- by glibc. This is primarily intended to support libstd++
- functionality.
- However, it also allows thread-specific locale selection via
- uselocale().
- Most people will answer N.
- config UCLIBC_HAS_HEXADECIMAL_FLOATS
- bool "Support hexadecimal float notation"
- depends on UCLIBC_HAS_CTYPE_TABLES
- depends on UCLIBC_HAS_FLOATS
- help
- Answer Y to enable support for hexadecimal float notation in the
- (wchar and) char string to floating point conversion functions, as
- well as support for the %a and %A conversion specifiers in the
- *printf() and *scanf() functions.
- Most people will answer N.
- config UCLIBC_HAS_GLIBC_DIGIT_GROUPING
- bool "Support glibc's \"'\" flag for allowing locale-specific digit grouping"
- depends on UCLIBC_HAS_LOCALE
- depends on UCLIBC_HAS_FLOATS
- help
- Answer Y to enable support for glibc's \"'\" flag for allowing
- locale-specific digit grouping in base 10 integer conversions and
- appropriate floating point conversions in the *printf() and *scanf()
- functions.
- Most people will answer N.
- config UCLIBC_HAS_SCANF_LENIENT_DIGIT_GROUPING
- bool "Do not require digit grouping when the \"'\" flag is specified"
- depends on UCLIBC_HAS_GLIBC_DIGIT_GROUPING
- default y
- help
- Answer Y to make digit grouping optional when the \"'\" flag is
- specified.
- This is the standard glibc behavior. If the initial string of digits
- exceeds the maximum group number, the input will be treated as a
- normal non-grouped number.
- Most people will answer N.
- config UCLIBC_HAS_GLIBC_CUSTOM_PRINTF
- bool "Support glibc's register_printf_function() (glibc-compat)"
- depends on !USE_OLD_VFPRINTF
- help
- Answer Y to support glibc's register_printf_function() to allow an
- application to add its own printf conversion specifiers.
- parse_printf_format() is also enabled.
- NOTE: Limits the number or registered specifiers to 10.
- NOTE: Requires new conversion specifiers to be ASCII
- characters (0-0x7f). This is to avoid problems with processing
- format strings in locales with different multibyte conversions.
- Most people will answer N.
- config USE_OLD_VFPRINTF
- bool "Use the old vfprintf implementation"
- depends on !UCLIBC_HAS_WCHAR
- help
- Set to true to use the old vfprintf instead of the new. This is
- roughly C89 compliant with some extensions, and is much smaller.
- However, it does not support wide chars, positional args, or glibc
- custom printf specifiers.
- Most people will answer N.
- config UCLIBC_PRINTF_SCANF_POSITIONAL_ARGS
- int "Maximum number of positional args. Either 0 or >= 9."
- depends on !USE_OLD_VFPRINTF
- default 9
- help
- Set the maximum number of positional args supported by the
- printf/scanf functions. The Single Unix Specification Version 3
- requires a minimum value of 9. Setting this to a value lower than
- 9 will disable positional arg support and cause the NL_ARGMAX macro
- in limits.h to be #undef'd.
- WARNING! The workspace to support positional args is currently
- allocated on the stack. You probably don't want to set
- this to too high a value.
- Most people will answer 9.
- choice
- prompt "Stdio buffer size"
- default UCLIBC_HAS_STDIO_BUFSIZ_4096
- help
- Please select a value for BUFSIZ. This will be used by the
- stdio subsystem as the default buffer size for a file, and
- affects fopen(), setvbuf(), etc.
- NOTE: Setting this to 'none' will disable buffering completely.
- However, BUFSIZ will still be defined in stdio.h as 256 because
- many applications use this value.
- config UCLIBC_HAS_STDIO_BUFSIZ_NONE
- bool "none (WARNING - BUFSIZ will be 256 in stdio.h)"
- depends on !UCLIBC_HAS_WCHAR
- config UCLIBC_HAS_STDIO_BUFSIZ_256
- bool "256 (minimum ANSI/ISO C99 value)"
- config UCLIBC_HAS_STDIO_BUFSIZ_512
- bool "512"
- config UCLIBC_HAS_STDIO_BUFSIZ_1024
- bool "1024"
- config UCLIBC_HAS_STDIO_BUFSIZ_2048
- bool "2048"
- config UCLIBC_HAS_STDIO_BUFSIZ_4096
- bool "4096"
- config UCLIBC_HAS_STDIO_BUFSIZ_8192
- bool "8192"
- # If you add more choices, you will need to update uClibc_stdio.h.
- endchoice
- choice
- prompt "Stdio builtin buffer size (uClibc-specific)"
- depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
- default UCLIBC_HAS_STDIO_BUILTIN_BUFFER_NONE
- help
- When a FILE is created with fopen(), an attempt is made to allocate
- a BUFSIZ buffer for it. If the allocation fails, fopen() will still
- succeed but the FILE will be unbuffered.
- This option adds a small amount of space to each FILE to act as an
- emergency buffer in the event of a buffer allocation failure.
- Most people will answer None.
- config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_NONE
- bool "None"
- config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_4
- bool "4"
- config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_8
- bool "8"
- # If you add more choices, you will need to update uClibc_stdio.h.
- endchoice
- config UCLIBC_HAS_STDIO_SHUTDOWN_ON_ABORT
- bool "Attempt to shutdown stdio subsystem when abort() is called."
- help
- ANSI/ISO C99 requires abort() to be asyn-signal-safe. So there was
- a behavioral change made in SUSv3. Previously, abort() was required
- to have the affect of fclose() on all open streams. The wording has
- been changed to "may" from "shall".
- Most people will answer N.
- config UCLIBC_HAS_STDIO_GETC_MACRO
- bool "Provide a macro version of getc()"
- depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
- default y
- help
- Provide a macro version of getc().
- Most people will answer Y.
- config UCLIBC_HAS_STDIO_PUTC_MACRO
- bool "Provide a macro version of putc()"
- depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
- default y
- help
- Provide a macro version of putc().
- Most people will answer Y.
- config UCLIBC_HAS_STDIO_AUTO_RW_TRANSITION
- bool "Support auto-r/w transition"
- default y
- help
- Answer Y to enable the stdio subsystem to automaticly transition
- between reading and writing. This relaxes the ANSI/ISO C99
- requirement:
- When a file is opened with update mode ('+' as the second or third
- character in the list of mode argument values), both input and output
- may be performed on the associated stream. However, output shall not
- be directly followed by input without an intervening call to the
- fflush function or to a file positioning function (fseek, fsetpos,
- or rewind), and input shall not be directly followed by output without
- an intervening call to a file positioning function, unless the input
- operation encounters endoffile.
- Most people will answer Y.
- config UCLIBC_HAS_FOPEN_LARGEFILE_MODE
- bool "Support an fopen() 'F' flag for large file mode (uClibc-specific)"
- help
- Answer Y to enable a uClibc-specific extension to allow passing an
- additional 'F' flag in the mode string for fopen() to specify that
- the file should be open()ed with the O_LARGEFILE flag set.
- Most people will answer N.
- config UCLIBC_HAS_FOPEN_EXCLUSIVE_MODE
- bool "Support an fopen() 'x' flag for exclusive mode (glibc-compat)"
- help
- Answer Y to support a glibc extension to allow passing
- additional 'x' flag in the mode string for fopen() to specify that
- the file should be open()ed with the O_EXCL flag set.
- Most people will answer N.
- config UCLIBC_HAS_FOPEN_CLOSEEXEC_MODE
- bool "Support an fopen() 'e' flag for close-on-exec mode (glibc-compat)"
- help
- Answer Y to support a glibc extension to allow passing
- additional 'e' flag in the mode string for fopen() to specify that
- the file should be open()ed with the O_CLOEXEC flag set.
- Most people will answer N.
- config UCLIBC_HAS_GLIBC_CUSTOM_STREAMS
- bool "Support fmemopen(), open_memstream(), and fopencookie() (glibc-compat)"
- help
- Answer Y to support the glibc 'custom stream' extension functions
- fmemopen(), open_memstream(), and fopencookie().
- NOTE: There are some minor differences regarding seeking behavior.
- Most people will answer N.
- config UCLIBC_HAS_PRINTF_M_SPEC
- bool "Support the '%m' specifier in printf format strings (glibc-compat)"
- help
- Answer Y to support a glibc extension to interpret '%m' in printf
- format strings as an instruction to output the error message string
- (as generated by strerror) corresponding to the current value of
- 'errno'.
- Most people will answer N.
- config UCLIBC_HAS_ERRNO_MESSAGES
- bool "Include the errno message text in the library"
- default y
- help
- Answer Y if you want to include the errno message text in the
- library. This adds about 3K to the library, but enables strerror()
- to generate text other than 'Unknown error <number>'.
- Most people will answer Y.
- config UCLIBC_HAS_SYS_ERRLIST
- bool "Support sys_errlist[] (obsolete-compat)"
- depends on UCLIBC_HAS_ERRNO_MESSAGES
- help
- Answer Y if you want to support the obsolete sys_errlist[].
- This adds about 0.5k to the library, except for the mips
- arch where it adds over 4K.
- WARNING! In the future, support for sys_errlist[] may be unavailable
- in at least some configurations. In fact, it may be removed
- altogether.
- Most people will answer N.
- Application writers: use the strerror(3) function.
- config UCLIBC_HAS_SIGNUM_MESSAGES
- bool "Include the signum message text in the library"
- default y
- help
- Answer Y if you want to include the signum message text in the
- library. This adds about 0.5K to the library, but enables strsignal()
- to generate text other than 'Unknown signal <number>'.
- Most people will answer Y.
- config UCLIBC_HAS_SYS_SIGLIST
- bool "Support sys_siglist[] (bsd-compat)"
- depends on UCLIBC_HAS_SIGNUM_MESSAGES
- help
- Answer Y if you want to support sys_siglist[].
- WARNING! In the future, support for sys_siglist[] may be unavailable
- in at least some configurations. In fact, it may be removed
- altogether.
- Most people will answer N.
- config UCLIBC_HAS_GNU_GETOPT
- bool "Support gnu getopt"
- default y
- help
- Answer Y if you want to include full gnu getopt() instead of a
- (much smaller) SUSv3 compatible getopt().
- Note that getopt_long, getopt_long_only as well as getsubopt
- are implemented on top of this choice.
- Most people will answer Y.
- config UCLIBC_HAS_GETOPT_LONG
- bool "Support getopt_long/getopt_long_only (glibc-compat)"
- default y
- help
- Answer Y if you want to include getopt_long[_only()] used by many
- apps.
- Most people will answer Y.
- config UCLIBC_HAS_GNU_GETSUBOPT
- bool "Support getsubopt"
- default y
- help
- Answer Y if you want to include getsubopt().
- Most people will answer Y.
- config UCLIBC_HAS_ARGP
- bool "Support argp (as standalone shared object)"
- select UCLIBC_HAS_GETOPT_LONG
- select UCLIBC_HAS_GNU_GETOPT
- default n
- help
- Argp is an interface for parsing unix-style argument vectors. Unlike
- the common getopt interface, it provides many advanced features in
- addition to parsing options, such as automatic output in response to
- `--help' and `--version' options.
- A library can export an argp option parser, which programs can easily
- use in conjunction with their own option parser.
- Argp support is needed by elfutils libdw.
- Most people can safely answer N.
- endmenu
- menu "Big and Tall"
- config UCLIBC_HAS_REGEX
- bool "Regular Expression Support"
- default y
- help
- POSIX regular expression code is really big -- 53k all by itself.
- If you don't use regular expressions, turn this off and save space.
- Of course, if you only statically link, leave this on, since it will
- only be included in your apps if you use regular expressions.
- config UCLIBC_HAS_REGEX_OLD
- bool "Use the older (stable) regular expression code"
- depends on UCLIBC_HAS_REGEX
- default y
- help
- There are two versions of regex. The older (stable) version has
- been in uClibc for quite a long time but hasn't seen too many
- updates. It also has some known issues when dealing with uncommon
- corner cases and multibyte/unicode strings. However, it is quite
- a bit smaller than the newer version.
- If the older version has worked for you and you don't need unicode
- support, then stick with the old version (and say Y here).
- Otherwise, you should use the new version (and say N here).
- config UCLIBC_HAS_FNMATCH
- bool "fnmatch Support"
- default y
- help
- POSIX fnmatch.
- config UCLIBC_HAS_FNMATCH_OLD
- bool "Use the older (stable) fnmatch code"
- depends on UCLIBC_HAS_FNMATCH
- default y
- help
- There are two versions of fnmatch. The older (stable) version has
- been in uClibc for quite a long time but hasn't seen too many
- updates. It also has some known issues when dealing with uncommon
- corner cases and multibyte/unicode strings. However, it is quite
- a bit smaller than the newer version.
- If the older version has worked for you and you don't need unicode
- support, then stick with the old version (and say Y here).
- Otherwise, you should use the new version (and say N here).
- config UCLIBC_HAS_WORDEXP
- bool "Support the wordexp() interface"
- depends on UCLIBC_HAS_GLOB
- help
- The SuSv3 wordexp() interface performs word expansions per the Shell
- and Utilities volume of IEEE Std 1003.1-2001, Section 2.6. It is
- intended for use by applications that want to implement all of the
- standard Bourne shell expansions on input data.
- This interface is rarely used, and very large. Unless you have a
- pressing need for wordexp(), you should probably answer N.
- config UCLIBC_HAS_NFTW
- bool "Support the nftw() interface"
- help
- The SuSv3 nftw() interface is used to recursively descend
- directory paths while repeatedly calling a function.
- This interface is rarely used, and adds around 4.5k. Unless you have
- a pressing need for nftw(), you should probably answer N.
- config UCLIBC_HAS_FTW
- bool "Support the ftw() interface (SUSv4-obsolete)"
- depends on UCLIBC_SUSV4_LEGACY
- help
- The SuSv3 ftw() interface is used to recursively descend
- directory paths while repeatedly calling a function.
- This interface is rarely used, and adds around 4.5k. Unless you have
- a pressing need for ftw(), you should probably answer N.
- config UCLIBC_HAS_FTS
- bool "Support the fts() interface (bsd-compat)"
- help
- The fts functions are provided for traversing UNIX file hierarchies.
- This interface is currently used by the elfutils and adds
- around 7.5k.
- You should port your application to use the POSIX nftw()
- interface.
- Unless you need to build/use elfutils, you should prolly answer N.
- config UCLIBC_HAS_GLOB
- bool "Support the glob() interface"
- depends on UCLIBC_HAS_FNMATCH
- default y
- help
- The glob interface is somewhat large (weighing in at about 2,5k). It
- is used fairly often, but is an option since people wanting to go for
- absolute minimum size may wish to omit it.
- Most people will answer Y.
- config UCLIBC_HAS_GNU_GLOB
- bool "Support gnu glob() interface"
- depends on UCLIBC_HAS_GLOB
- help
- The gnu glob interface is somewhat larger (weighing in at about 4,2k)
- than it's SuSv3 counterpart (and is out of date). It is an old copy
- from glibc and does not support all the GNU specific options.
- Answer Y if you want to include full gnu glob() instead of the smaller
- SUSv3 compatible glob().
- Most people will answer N.
- endmenu
- menu "Library Installation Options"
- config RUNTIME_PREFIX
- string "uClibc runtime library directory"
- default "/usr/$(TARGET_ARCH)-linux-uclibc/"
- help
- RUNTIME_PREFIX is the directory into which the uClibc runtime
- libraries will be installed. The result will look something
- like the following:
- $(RUNTIME_PREFIX)/
- lib/ <contains all runtime libraries>
- usr/bin/ldd <the ldd utility program>
- sbin/ldconfig <the ldconfig utility program>
- This value is used by the 'make install' Makefile target. Since this
- directory is compiled into the shared library loader, you will need to
- recompile uClibc if you change this value...
- For a typical target system this should be set to "/", such that
- 'make install' will install /lib/libuClibc-<VERSION>.so
- config DEVEL_PREFIX
- string "uClibc development environment directory"
- default "/usr/$(TARGET_ARCH)-linux-uclibc/usr/"
- help
- DEVEL_PREFIX is the directory into which the uClibc development
- environment will be installed. The result will look something
- like the following:
- $(DEVEL_PREFIX)/
- lib/ <contains static libs>
- include/ <Where all the header files go>
- This value is used by the 'make install' Makefile target when
- installing a uClibc development environment.
- For a typical target system this should be set to "/usr", such that
- 'make install' will install /usr/include/<header files>.
- config MULTILIB_DIR
- string "library path component"
- default "lib"
- help
- Path component where libraries reside.
- For a typical target system this should be set to "lib", such that
- 'make install' will install libraries to "/lib" and "/usr/lib"
- respectively
- DEVEL_PREFIX/MULTILIB_DIR
- RUNTIME_PREFIX/MULTILIB_DIR
- Other settings may include "lib32" or "lib64".
- config HARDWIRED_ABSPATH
- bool "Hardwire absolute paths into linker scripts"
- default y
- help
- This prepends absolute paths to the libraries mentioned in linker
- scripts such as libc.so.
- This is a build time optimization. It has no impact on dynamic
- linking at runtime, which doesn't use linker scripts.
- You must disable this to use uClibc with old non-sysroot toolchains,
- such as the prebuilt binary cross compilers at:
- http://uclibc.org/downloads/binaries
- The amount of time saved by this optimization is actually too small to
- measure. The linker just had to search the library path to find the
- linker script, so the dentries are cache hot if it has to search the
- same path again. But it's what glibc does, so we do it too.
- endmenu
- menu "Security options"
- config UCLIBC_BUILD_PIE
- bool "Build utilities as ET_DYN/PIE executables"
- depends on HAVE_SHARED
- depends on TARGET_arm || TARGET_frv || TARGET_i386 || TARGET_mips || TARGET_powerpc || TARGET_nds32
- select FORCE_SHAREABLE_TEXT_SEGMENTS
- help
- If you answer Y here, ldd and iconv are built as ET_DYN/PIE
- executables.
- It requires gcc-3.4 and binutils-2.15 (for arm 2.16) or later.
- More about ET_DYN/PIE binaries on <http://pax.grsecurity.net/> .
- WARNING: This option also enables FORCE_SHAREABLE_TEXT_SEGMENTS, so
- all libraries have to be built with -fPIC or -fpic, and all
- assembler functions must be written as position independent
- code (PIC).
- config UCLIBC_HAS_ARC4RANDOM
- bool "Include the arc4random() function"
- help
- Answer Y to support the OpenBSD-like arc4random() function. This
- function picks a random number between 0 and N, and will always return
- something even if the random driver is dead. If urandom fails then
- gettimeofday(2) will be used as the random seed. This function is
- designed to be more dependable than invoking /dev/urandom directly.
- OpenSSL and OpenNTPD currently support this function.
- Most people will answer N.
- config ARC4RANDOM_USES_NODEV
- bool "Do not use /dev/urandom with arc4random()"
- depends on UCLIBC_HAS_ARC4RANDOM
- help
- Answer Y to use gettimeofday(2) and getpid(2) exclusively for
- arc4random(). This is not a bad idea for a diskless system, but
- it uses a lot of syscalls to stir each array element.
- Most people will answer N.
- config HAVE_NO_SSP
- bool
- config UCLIBC_HAS_SSP
- bool "Support for GCC stack smashing protector"
- depends on !HAVE_NO_SSP
- help
- Add code to support GCC's -fstack-protector[-all] option to uClibc.
- This requires GCC 4.1 or newer. GCC does not have to provide libssp,
- the needed functions are added to ldso/libc instead.
- GCC's stack protector is a reimplementation of IBM's propolice.
- See http://www.trl.ibm.com/projects/security/ssp/ and
- http://www.linuxfromscratch.org/hints/downloads/files/ssp.txt
- for details.
- Note that NOEXECSTACK on a kernel with address space randomization
- is generally sufficient to prevent most buffer overflow exploits
- without increasing code size. This option essentially adds debugging
- code to catch them.
- Most people will answer N.
- config SSP_QUICK_CANARY
- bool "Use simple guard values without accessing /dev/urandom"
- depends on UCLIBC_HAS_SSP
- help
- Use gettimeofday(2) to define the __guard without accessing
- /dev/urandom.
- WARNING: This makes smashing stack protector vulnerable to timing
- attacks.
- Most people will answer N.
- choice
- prompt "Propolice protection blocking signal"
- depends on UCLIBC_HAS_SSP
- depends on DODEBUG
- default PROPOLICE_BLOCK_SEGV
- help
- "abort" use SIGABRT to block offending programs.
- This is the default implementation.
- "segfault" use SIGSEGV to block offending programs.
- Use this for debugging.
- If unsure, answer "abort".
- config PROPOLICE_BLOCK_ABRT
- bool "abort"
- config PROPOLICE_BLOCK_SEGV
- bool "segfault"
- endchoice
- config UCLIBC_BUILD_SSP
- bool "Build uClibc with -fstack-protector"
- depends on UCLIBC_HAS_SSP
- help
- Build all uClibc libraries and executables with -fstack-protector,
- adding extra stack overflow checking to most uClibc functions.
- config UCLIBC_BUILD_RELRO
- bool "Build uClibc with linker option -z RELRO"
- depends on HAVE_SHARED
- default y
- help
- Build all libraries and executables with "ld -z relro".
- This tells the linker to mark chunks of an executable or shared
- library read-only after applying dynamic relocations. (This comes
- up when a global const variable is initialized to the address of a
- function or the value of another global variable.)
- This is a fairly obscure option the ld man page doesn't even bother
- to document properly. It's a security paranoia issue that's more
- likely to consume memory (by allocating an extra page) rather than
- save it.
- This is explained in more depth at
- http://www.airs.com/blog/archives/189
- Nobody is likely to care whether you say Y or N here.
- config UCLIBC_BUILD_NOW
- bool "Build uClibc with linker option -z NOW"
- depends on HAVE_SHARED
- help
- Build all libraries and executables with "ld -z now".
- This tells the linker to resolve all symbols when the library is
- first loaded, rather than when each function is first called. This
- increases start-up latency by a few microseconds and may do
- unnecessary work (resolving symbols that are never used), but the
- realtime people like it for making microbenchmark timings slightly
- more predictable and in some cases it can be slightly faster due to
- CPU cache behavior (not having to fault the linker back in to do
- lazy symbol resolution).
- Most people can't tell the difference between selecting Y or N here.
- config UCLIBC_BUILD_NOEXECSTACK
- bool "Build uClibc with noexecstack marking"
- default y
- help
- Mark all assembler files as noexecstack, which will mark uClibc
- as not requiring an executable stack. (This doesn't prevent other
- files you link against from claiming to need an executable stack, it
- just won't cause uClibc to request it unnecessarily.)
- This is a security thing to make buffer overflows harder to exploit.
- By itself, it's kind of useless, as Linus Torvalds explained in 1998:
- http://old.lwn.net/1998/0806/a/linus-noexec.html
- It only actually provides any security when combined with address
- space randomization, explained here: http://lwn.net/Articles/121845/
- Address space randomization is on by default in current linux
- kernels (although it can be disabled using the option
- CONFIG_COMPAT_BRK).
- You should probably say Y.
- endmenu
- menu "Development/debugging options"
- config CROSS_COMPILER_PREFIX
- string "Cross-compiling toolchain prefix"
- default ""
- help
- The prefix used to execute your cross-compiling toolchain. For
- example, if you run 'arm-linux-uclibc-gcc' to compile something,
- then enter 'arm-linux-uclibc-' here.
- config UCLIBC_EXTRA_CFLAGS
- string "Extra CFLAGS"
- default ""
- help
- Add any additional CFLAGS to be used to build uClibc.
- config DODEBUG
- bool "Enable debugging symbols"
- select EXTRA_WARNINGS
- help
- Say Y here if you wish to compile uClibc with debugging symbols.
- This will allow you to use a debugger to examine uClibc internals
- while applications are running. This increases the size of the
- library considerably and should only be used when doing development.
- If you are doing development and want to debug uClibc, answer Y.
- Otherwise, answer N.
- config DODEBUG_PT
- bool "Build pthread with debugging output"
- depends on UCLIBC_HAS_THREADS && UCLIBC_HAS_LINUXTHREADS
- help
- Enable debug output in libpthread. This is only useful when doing
- development in libpthread itself.
- Otherwise, answer N.
- config DOSTRIP
- bool "Strip libraries and executables"
- default y
- depends on !DODEBUG
- help
- Say Y here if you do wish to strip all uClibc libraries and
- executables. No stripping increases the size of the binaries
- considerably, but makes it possible to debug uClibc libraries.
- Most people will answer Y.
- config DOASSERTS
- bool "Build with run-time assertion testing"
- help
- Say Y here to include runtime assertion tests.
- This enables runtime assertion testing in some code, which can
- increase the size of the library and incur runtime overhead.
- If you say N, then this testing will be disabled.
- config SUPPORT_LD_DEBUG
- bool "Build the shared library loader with debugging support"
- depends on HAVE_SHARED
- help
- Answer Y here to enable all the extra code needed to debug the uClibc
- native shared library loader. The level of debugging noise that is
- generated depends on the LD_DEBUG environment variable... Just set
- LD_DEBUG to something like: 'LD_DEBUG=token1,token2,.. prog' to
- debug your application. Diagnostic messages will then be printed to
- the stderr.
- For now these debugging tokens are available:
- detail provide more information for some options
- move display copy processing
- symbols display symbol table processing
- reloc display relocation processing; detail shows the
- relocation patch
- nofixups never fixes up jump relocations
- bindings displays the resolve processing (function calls);
- detail shows the relocation patch
- all Enable everything!
- The additional environment variable:
- LD_DEBUG_OUTPUT=file
- redirects the diagnostics to an output file created using
- the specified name and the process id as a suffix.
- An excellent start is simply:
- $ LD_DEBUG=binding,move,symbols,reloc,detail ./appname
- or to log everything to a file named 'logfile', try this
- $ LD_DEBUG=all LD_DEBUG_OUTPUT=logfile ./appname
- If you are doing development and want to debug uClibc's shared library
- loader, answer Y. Mere mortals answer N.
- config SUPPORT_LD_DEBUG_EARLY
- bool "Build the shared library loader with early debugging support"
- depends on HAVE_SHARED
- help
- Answer Y here to if you find the uClibc shared library loader is
- crashing or otherwise not working very early on. This is typical
- only when starting a new port when you haven't figured out how to
- properly get the values for argc, argv, environ, etc. This method
- allows a degree of visibility into the very early shared library
- loader initialization process. If you are doing development and want
- to debug the uClibc shared library loader early initialization,
- answer Y. Mere mortals answer N.
- config UCLIBC_MALLOC_DEBUGGING
- bool "Build malloc with debugging support"
- depends on MALLOC || MALLOC_STANDARD
- select DOASSERTS
- help
- Answer Y here to compile extra debugging support code into malloc.
- Malloc debugging output may then be enabled at runtime using the
- MALLOC_DEBUG environment variable.
- The value of MALLOC_DEBUG should be an integer, which is interpreted
- as a bitmask with the following bits:
- 1 - do extra consistency checking
- 2 - output messages for malloc/free calls and OS
- allocation calls
- 4 - output messages for the `MMB' layer
- 8 - output messages for internal malloc heap manipulation
- calls
- Because this increases the size of malloc appreciably (due to strings
- etc), you should say N unless you need to debug a malloc problem.
- config UCLIBC_HAS_BACKTRACE
- bool "Add support for application self-debugging"
- depends on HAVE_SHARED
- help
- Answer Y here to compile support for application self-debugging that
- provides the following new functions:
- backtrace, backtrace_symbols, backtrace_symbols_fd
- The backtrace functionality is currently supported on some platforms, and it
- based on dwarf2 informations to properly work, so any application that
- want to use backtrace needs to be built with -fexceptions flag.
- The symbol names may be unavailable without the use of special linker
- options. For systems using the GNU linker, it is necessary to use the
- -rdynamic linker option too. Note that names of "static" functions are not
- exposed, and won't be available in the backtrace.
- config WARNINGS
- string "Compiler Warnings"
- default "-Wall"
- help
- Set this to the set of compiler warnings you wish to see while compiling.
- config EXTRA_WARNINGS
- bool "Enable extra annoying warnings"
- help
- If you wish to build with extra warnings enabled, say Y here.
- endmenu
|