Config.in 67 KB

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  1. #
  2. # For a description of the syntax of this configuration file,
  3. # see extra/config/Kconfig-language.txt
  4. #
  5. mainmenu "uClibc C Library Configuration"
  6. config DESIRED_TARGET_ARCH
  7. string
  8. option env="ARCH"
  9. choice
  10. prompt "Target Architecture"
  11. default TARGET_alpha if DESIRED_TARGET_ARCH = "alpha"
  12. default TARGET_arm if DESIRED_TARGET_ARCH = "arm"
  13. default TARGET_avr32 if DESIRED_TARGET_ARCH = "avr32"
  14. default TARGET_bfin if DESIRED_TARGET_ARCH = "bfin"
  15. default TARGET_cris if DESIRED_TARGET_ARCH = "cris"
  16. default TARGET_e1 if DESIRED_TARGET_ARCH = "e1"
  17. default TARGET_frv if DESIRED_TARGET_ARCH = "frv"
  18. default TARGET_h8300 if DESIRED_TARGET_ARCH = "h8300"
  19. default TARGET_hppa if DESIRED_TARGET_ARCH = "hppa"
  20. default TARGET_i386 if DESIRED_TARGET_ARCH = "i386"
  21. default TARGET_i960 if DESIRED_TARGET_ARCH = "i960"
  22. default TARGET_ia64 if DESIRED_TARGET_ARCH = "ia64"
  23. default TARGET_m68k if DESIRED_TARGET_ARCH = "m68k"
  24. default TARGET_microblaze if DESIRED_TARGET_ARCH = "microblaze"
  25. default TARGET_mips if DESIRED_TARGET_ARCH = "mips"
  26. default TARGET_nios if DESIRED_TARGET_ARCH = "nios"
  27. default TARGET_nios2 if DESIRED_TARGET_ARCH = "nios2"
  28. default TARGET_powerpc if DESIRED_TARGET_ARCH = "powerpc"
  29. default TARGET_sh if DESIRED_TARGET_ARCH = "sh"
  30. default TARGET_sh64 if DESIRED_TARGET_ARCH = "sh64"
  31. default TARGET_sparc if DESIRED_TARGET_ARCH = "sparc"
  32. default TARGET_v850 if DESIRED_TARGET_ARCH = "v850"
  33. default TARGET_vax if DESIRED_TARGET_ARCH = "vax"
  34. default TARGET_x86_64 if DESIRED_TARGET_ARCH = "x86_64"
  35. default TARGET_xtensa if DESIRED_TARGET_ARCH = "xtensa"
  36. help
  37. The architecture of your target.
  38. config TARGET_alpha
  39. bool "alpha"
  40. config TARGET_arm
  41. bool "arm"
  42. config TARGET_avr32
  43. bool "avr32"
  44. config TARGET_bfin
  45. bool "bfin"
  46. config TARGET_cris
  47. bool "cris"
  48. config TARGET_e1
  49. bool "e1 (BROKEN)"
  50. config TARGET_frv
  51. bool "frv (BROKEN)"
  52. config TARGET_h8300
  53. bool "h8300 (BROKEN)"
  54. config TARGET_hppa
  55. bool "hppa"
  56. config TARGET_i386
  57. bool "i386"
  58. config TARGET_i960
  59. bool "i960 (BROKEN)"
  60. config TARGET_ia64
  61. bool "ia64"
  62. config TARGET_m68k
  63. bool "m68k"
  64. config TARGET_microblaze
  65. bool "microblaze (BROKEN)"
  66. config TARGET_mips
  67. bool "mips"
  68. config TARGET_nios
  69. bool "nios"
  70. config TARGET_nios2
  71. bool "nios2"
  72. config TARGET_powerpc
  73. bool "powerpc"
  74. config TARGET_sh
  75. bool "superh"
  76. config TARGET_sh64
  77. bool "sh64"
  78. config TARGET_sparc
  79. bool "sparc"
  80. config TARGET_v850
  81. bool "v850 (BROKEN)"
  82. config TARGET_vax
  83. bool "vax"
  84. config TARGET_x86_64
  85. bool "x86_64"
  86. config TARGET_xtensa
  87. bool "xtensa"
  88. endchoice
  89. menu "Target Architecture Features and Options"
  90. if TARGET_alpha
  91. source "extra/Configs/Config.alpha"
  92. endif
  93. if TARGET_arm
  94. source "extra/Configs/Config.arm"
  95. endif
  96. if TARGET_avr32
  97. source "extra/Configs/Config.avr32"
  98. endif
  99. if TARGET_bfin
  100. source "extra/Configs/Config.bfin"
  101. endif
  102. if TARGET_cris
  103. source "extra/Configs/Config.cris"
  104. endif
  105. if TARGET_e1
  106. source "extra/Configs/Config.e1"
  107. endif
  108. if TARGET_frv
  109. source "extra/Configs/Config.frv"
  110. endif
  111. if TARGET_h8300
  112. source "extra/Configs/Config.h8300"
  113. endif
  114. if TARGET_hppa
  115. source "extra/Configs/Config.hppa"
  116. endif
  117. if TARGET_i386
  118. source "extra/Configs/Config.i386"
  119. endif
  120. if TARGET_i960
  121. source "extra/Configs/Config.i960"
  122. endif
  123. if TARGET_ia64
  124. source "extra/Configs/Config.ia64"
  125. endif
  126. if TARGET_m68k
  127. source "extra/Configs/Config.m68k"
  128. endif
  129. if TARGET_nios
  130. source "extra/Configs/Config.nios"
  131. endif
  132. if TARGET_nios2
  133. source "extra/Configs/Config.nios2"
  134. endif
  135. if TARGET_microblaze
  136. source "extra/Configs/Config.microblaze"
  137. endif
  138. if TARGET_mips
  139. source "extra/Configs/Config.mips"
  140. endif
  141. if TARGET_powerpc
  142. source "extra/Configs/Config.powerpc"
  143. endif
  144. if TARGET_sh
  145. source "extra/Configs/Config.sh"
  146. endif
  147. if TARGET_sh64
  148. source "extra/Configs/Config.sh64"
  149. endif
  150. if TARGET_sparc
  151. source "extra/Configs/Config.sparc"
  152. endif
  153. if TARGET_v850
  154. source "extra/Configs/Config.v850"
  155. endif
  156. if TARGET_vax
  157. source "extra/Configs/Config.vax"
  158. endif
  159. if TARGET_x86_64
  160. source "extra/Configs/Config.x86_64"
  161. endif
  162. if TARGET_xtensa
  163. source "extra/Configs/Config.xtensa"
  164. endif
  165. config TARGET_SUBARCH
  166. string
  167. default "e500" if CONFIG_E500
  168. default "classic" if CONFIG_CLASSIC
  169. default "sh4" if CONFIG_SH4
  170. default ""
  171. source "extra/Configs/Config.in.arch"
  172. endmenu
  173. menu "General Library Settings"
  174. config HAVE_NO_PIC
  175. bool
  176. default n
  177. config DOPIC
  178. bool "Generate only Position Independent Code (PIC)"
  179. default y
  180. depends on !HAVE_NO_PIC
  181. help
  182. If you wish to build all of uClibc as PIC objects, then answer Y here.
  183. If you are unsure, then you should answer N.
  184. config ARCH_HAS_NO_SHARED
  185. bool
  186. default n
  187. config ARCH_HAS_NO_LDSO
  188. bool
  189. select ARCH_HAS_NO_SHARED
  190. default n
  191. config HAVE_SHARED
  192. bool "Enable support for shared libraries"
  193. depends on !ARCH_HAS_NO_SHARED
  194. default y
  195. help
  196. If you wish to build uClibc with support for shared libraries then
  197. answer Y here. If you only want to build uClibc as a static library,
  198. then answer N.
  199. config FORCE_SHAREABLE_TEXT_SEGMENTS
  200. bool "Only load shared libraries which can share their text segment"
  201. depends on HAVE_SHARED
  202. default n
  203. help
  204. If you answer Y here, the uClibc native shared library loader will
  205. only load shared libraries, which do not need to modify any
  206. non-writable segments. These libraries haven't set the DT_TEXTREL
  207. tag in the dynamic section (==> objdump).
  208. All your libraries must be compiled with -fPIC or -fpic, and all
  209. assembler function must be written as position independent code (PIC).
  210. Enabling this option will make uClibc's shared library loader a
  211. little bit smaller and guarantee that no memory will be wasted by
  212. badly coded shared libraries.
  213. config LDSO_LDD_SUPPORT
  214. bool "Native 'ldd' support"
  215. depends on HAVE_SHARED
  216. default y
  217. help
  218. Enable this to enable all the code needed to support traditional ldd,
  219. which executes the shared library loader to resolve all dependencies
  220. and then provide a list of shared libraries that are required for an
  221. application to function. Disabling this option will makes uClibc's
  222. shared library loader a little bit smaller.
  223. Most people will answer Y.
  224. config LDSO_CACHE_SUPPORT
  225. bool "Enable library loader cache (ld.so.conf)"
  226. depends on HAVE_SHARED
  227. default y
  228. help
  229. Enable this to make use of /etc/ld.so.conf, the shared library loader
  230. cache configuration file to support for non-standard library paths.
  231. After updating this file, it is necessary to run 'ldconfig' to update
  232. the /etc/ld.so.cache shared library loader cache file.
  233. config LDSO_PRELOAD_FILE_SUPPORT
  234. bool "Enable library loader preload file (ld.so.preload)"
  235. depends on HAVE_SHARED
  236. default n
  237. help
  238. Enable this to make use of /etc/ld.so.preload. This file contains a
  239. whitespace separated list of shared libraries to be loaded before
  240. the program.
  241. config LDSO_BASE_FILENAME
  242. string "Shared library loader naming prefix"
  243. depends on HAVE_SHARED && (LDSO_CACHE_SUPPORT || LDSO_PRELOAD_FILE_SUPPORT)
  244. default "ld.so"
  245. help
  246. If you wish to support both uClibc and glibc on the same system, it
  247. is necessary to set this to something other than "ld.so" to avoid
  248. conflicts with glibc, which also uses "ld.so". This prevents both
  249. libraries from using the same /etc/ld.so.* files. If you wish to
  250. support both uClibc and glibc on the same system then you should set
  251. this to "ld-uClibc.so".
  252. Most people will leave this set to the default of "ld.so".
  253. WARNING: Changing the default prefix could cause problems with
  254. binutils' ld !
  255. config UCLIBC_STATIC_LDCONFIG
  256. bool "Link ldconfig statically"
  257. depends on HAVE_SHARED
  258. default y
  259. help
  260. Enable this option to statically link the ldconfig binary.
  261. Making ldconfig static can be beneficial if you have a library
  262. problem and need to use ldconfig to recover. Sometimes, it is
  263. preferable to instead keep the size of the system down, in which
  264. case you should disable this option.
  265. config LDSO_RUNPATH
  266. bool "Enable ELF RUNPATH tag support"
  267. depends on HAVE_SHARED
  268. default y
  269. help
  270. ELF's may have dynamic RPATH/RUNPATH tags. These tags list paths
  271. which extend the library search paths. They are really only useful
  272. if a package installs libraries in non standard locations and
  273. ld.so.conf support is disabled.
  274. Usage of RUNPATH tags is not too common, so disabling this feature
  275. should be safe for most people.
  276. config UCLIBC_CTOR_DTOR
  277. bool "Support global constructors and destructors"
  278. default y
  279. help
  280. If you wish to build uClibc with support for global constructor
  281. (ctor) and global destructor (dtor) support, then answer Y here.
  282. When ctor/dtor support is enabled, binaries linked with uClibc must
  283. also be linked with crtbegin.o and crtend.o which are provided by gcc
  284. (the "*startfile:" and "*endfile:" settings in your gcc specs file
  285. may need to be adjusted to include these files). This support will
  286. also add a small amount of additional size to each binary compiled vs
  287. uClibc. If you will be using uClibc with C++, or if you need the gcc
  288. __attribute__((constructor)) and __attribute__((destructor)) to work,
  289. then you definitely want to answer Y here. If you don't need ctors
  290. or dtors and want your binaries to be as small as possible, then
  291. answer N.
  292. config LDSO_GNU_HASH_SUPPORT
  293. bool "Enable GNU hash style support"
  294. depends on HAVE_SHARED
  295. default n
  296. help
  297. Newest binutils support a new hash style named GNU-hash. The dynamic
  298. linker will use the new GNU-hash section (.gnu.hash) for symbol lookup
  299. if present into the ELF binaries, otherwise it will use the old SysV
  300. hash style (.hash). This ensures that it is completely backward
  301. compatible.
  302. Further, being the hash table implementation self-contained into each
  303. executable and shared libraries, objects with mixed hash style can
  304. peacefully coexist in the same process.
  305. If you want to use this new feature, answer Y
  306. config HAS_NO_THREADS
  307. bool
  308. default n
  309. config UCLIBC_HAS_THREADS
  310. bool "POSIX Threading support"
  311. depends on !HAS_NO_THREADS
  312. default y
  313. # linuxthreads and linuxthreads.old need nanosleep()
  314. select UCLIBC_HAS_REALTIME
  315. help
  316. If you want to compile uClibc with pthread support, then answer Y.
  317. This will increase the size of uClibc by adding a bunch of locking
  318. to critical data structures, and adding extra code to ensure that
  319. functions are properly reentrant.
  320. If your applications require pthreads, answer Y.
  321. config UCLIBC_HAS_TLS
  322. bool "Thread-Local Storage"
  323. depends on UCLIBC_HAS_THREADS && !LINUXTHREADS_OLD
  324. default n
  325. help
  326. If you want to enable TLS support then answer Y.
  327. This is fast an efficient way to store per-thread local data
  328. which is not on stack. It needs __thread support enabled in
  329. gcc.
  330. config PTHREADS_DEBUG_SUPPORT
  331. bool "Build pthreads debugging support"
  332. default n
  333. depends on UCLIBC_HAS_THREADS
  334. help
  335. Say Y here if you wish to be able to debug applications that use
  336. uClibc's pthreads library. By enabling this option, a library
  337. named libthread_db will be built. This library will be dlopen()'d
  338. by gdb and will allow gdb to debug the threads in your application.
  339. IMPORTANT NOTE! Because gdb must dlopen() the libthread_db library,
  340. you must compile gdb with uClibc in order for pthread debugging to
  341. work properly.
  342. If you are doing development and want to debug applications using
  343. uClibc's pthread library, answer Y. Otherwise, answer N.
  344. config LINUXTHREADS_OLD
  345. bool "Use the older (stable) version of linuxthreads"
  346. default y
  347. depends on UCLIBC_HAS_THREADS && !UCLIBC_HAS_THREADS_NATIVE
  348. help
  349. There are two versions of linuxthreads. The older (stable) version
  350. has been in uClibc for quite a long time but hasn't seen too many
  351. updates other than bugfixes.
  352. The new version has not been tested much, and lacks ports for arches
  353. which glibc does not support (like bfin/frv/etc...), but is based on
  354. the latest code from glibc, so it may be the only choice for the
  355. newer ports (like alpha/amd64/64bit arches and hppa).
  356. config UCLIBC_HAS_THREADS_NATIVE
  357. bool "Native POSIX Threading (NPTL) Support"
  358. depends on UCLIBC_HAS_THREADS
  359. default n
  360. select UCLIBC_HAS_TLS
  361. help
  362. If you want to compile uClibc with NPTL support, then answer Y.
  363. IMPORTANT NOTE! NPTL requires a Linux 2.6 kernel, binutils
  364. at least version 2.16 and GCC with at least version 4.1.0. NPTL
  365. will not work with older versions of any above sources. If you
  366. ignore any of these guidelines, you do so at your own risk. Do
  367. not ask for help on any of the development mailing lists.
  368. !!!! WARNING !!!! BIG FAT WARNING !!!! REALLY BIG FAT WARNING !!!!
  369. This is experimental code and at times it may not even build and
  370. even if it does it might decide to do random damage. This code is
  371. potentially hazardous to your health and sanity. It will remain
  372. that way until further notice at which point this notice will
  373. disappear. Thank you for your support and for not smoking.
  374. config LINUXTHREADS_NEW
  375. def_bool y
  376. depends on UCLIBC_HAS_THREADS && !LINUXTHREADS_OLD && !UCLIBC_HAS_THREADS_NATIVE
  377. config UCLIBC_HAS_SYSLOG
  378. bool "Syslog support"
  379. default y
  380. depends on UCLIBC_HAS_NETWORK_SUPPORT
  381. select UCLIBC_HAS_SOCKET
  382. help
  383. Support sending messages to the system logger.
  384. This requires socket-support.
  385. config UCLIBC_HAS_LFS
  386. bool "Large File Support"
  387. default y
  388. help
  389. If you wish to build uClibc with support for accessing large files
  390. (i.e. files greater then 2 GiB) then answer Y. Do not enable this
  391. if you are using an older Linux kernel (2.0.x) that lacks large file
  392. support. Enabling this option will increase the size of uClibc.
  393. choice
  394. prompt "Malloc Implementation"
  395. default MALLOC if ! ARCH_USE_MMU
  396. default MALLOC_STANDARD if ARCH_USE_MMU
  397. config MALLOC
  398. bool "malloc"
  399. help
  400. "malloc" use mmap for all allocations and so works very well on
  401. MMU-less systems that do not support the brk() system call. It is
  402. pretty smart about reusing already allocated memory, and minimizing
  403. memory wastage.
  404. This is the default for uClinux MMU-less systems.
  405. config MALLOC_SIMPLE
  406. bool "malloc-simple"
  407. help
  408. "malloc-simple" is trivially simple and slow as molasses. It
  409. was written from scratch for uClibc, and is the simplest possible
  410. (and therefore smallest) malloc implementation.
  411. This uses only the mmap() system call to allocate and free memory,
  412. and does not use the brk() system call at all, making it a fine
  413. choice for MMU-less systems with very limited memory. It's 100%
  414. standards compliant, thread safe, very small, and releases freed
  415. memory back to the OS immediately rather than keeping it in the
  416. process's heap for reallocation. It is also VERY SLOW.
  417. config MALLOC_STANDARD
  418. bool "malloc-standard"
  419. depends on ARCH_USE_MMU
  420. help
  421. "malloc-standard" is derived from the public domain dlmalloc
  422. implementation by Doug Lea. It is quite fast, and is pretty smart
  423. about reusing already allocated memory, and minimizing memory
  424. wastage. This uses brk() for small allocations, while using mmap()
  425. for larger allocations. This is the default malloc implementation
  426. for uClibc.
  427. If unsure, answer "malloc-standard".
  428. endchoice
  429. config MALLOC_GLIBC_COMPAT
  430. bool "Malloc returns live pointer for malloc(0)"
  431. default n
  432. help
  433. The behavior of malloc(0) is listed as implementation-defined by
  434. SuSv3. Glibc returns a valid pointer to something, while uClibc
  435. normally returns NULL. I personally feel glibc's behavior is
  436. not particularly safe, and allows buggy applications to hide very
  437. serious problems.
  438. When this option is enabled, uClibc will act just like glibc, and
  439. return a live pointer when someone calls malloc(0). This pointer
  440. provides a malloc'ed area with a size of 1 byte. This feature is
  441. mostly useful when dealing with applications using autoconf's broken
  442. AC_FUNC_MALLOC macro (which redefines malloc as rpl_malloc if it
  443. does not detect glibc style returning-a-valid-pointer-for-malloc(0)
  444. behavior). Most people can safely answer N.
  445. config UCLIBC_DYNAMIC_ATEXIT
  446. bool "Dynamic atexit() Support"
  447. default y
  448. help
  449. When this option is enabled, uClibc will support an infinite number,
  450. of atexit() and on_exit() functions, limited only by your available
  451. memory. This can be important when uClibc is used with C++, since
  452. global destructors are implemented via atexit(), and it is quite
  453. possible to exceed the default number when this option is disabled.
  454. Enabling this option adds a few bytes, and more significantly makes
  455. atexit and on_exit depend on malloc, which can be bad when compiling
  456. static executables.
  457. Unless you use uClibc with C++, you should probably answer N.
  458. config COMPAT_ATEXIT
  459. bool "Old (visible) atexit Support"
  460. default n
  461. help
  462. Enable this option if you want to update from 0.9.28 to git/0.9.29,
  463. else you will be missing atexit() until you rebuild all apps.
  464. config UCLIBC_SUSV3_LEGACY
  465. bool "Enable SuSv3 LEGACY functions"
  466. default n
  467. #vfork,
  468. # h_errno
  469. # gethostbyaddr
  470. # gethostbyname
  471. help
  472. Enable this option if you want to have SuSv3 LEGACY functions
  473. in the library, else they are replaced by SuSv3 proposed macros.
  474. Currently applies to:
  475. bcmp, bcopy, bzero, index, rindex, ftime,
  476. bsd_signal, (ecvt), (fcvt), gcvt, (getcontext),
  477. (getwd), (makecontext),
  478. mktemp, (pthread_attr_getstackaddr), (pthread_attr_setstackaddr),
  479. scalb, (setcontext), (swapcontext), ualarm, usleep,
  480. wcswcs.
  481. WARNING! ABI incompatibility.
  482. config UCLIBC_SUSV3_LEGACY_MACROS
  483. bool "Enable SuSv3 LEGACY macros"
  484. default n
  485. help
  486. Enable this option if you want to have SuSv3 LEGACY macros.
  487. Currently applies to bcopy/bzero/bcmp/index/rindex et al.
  488. WARNING! ABI incompatibility.
  489. config UCLIBC_SUSV4_LEGACY
  490. bool "Enable SuSv4 LEGACY or obsolescent functions"
  491. default n
  492. help
  493. Enable this option if you want to have SuSv4 LEGACY functions
  494. and macros in the library.
  495. Currently applies to:
  496. - XSI functions:
  497. _longjmp, _setjmp, _tolower, _toupper, ftw, getitimer,
  498. gettimeofday, isascii, pthread_getconcurrency,
  499. pthread_setconcurrency, setitimer, setpgrp, sighold,
  500. sigignore, sigpause, sigrelse, sigset, siginterrupt,
  501. tempnam, toascii, ulimit.
  502. - Base functions:
  503. asctime, asctime_r, ctime, ctime_r, gets, rand_r,
  504. tmpnam, utime.
  505. WARNING! ABI incompatibility.
  506. config UCLIBC_HAS_STUBS
  507. bool "Provide stubs for unavailable functionality"
  508. default n
  509. help
  510. With this option uClibc provides non-functional stubs for
  511. functions which are impossible to implement on the target
  512. architecture. Otherwise, such functions are simply omitted.
  513. As of 2008-07, this option makes uClibc provide fork() stub
  514. on NOMMU targets. It always sets errno to ENOSYS and returns -1.
  515. This may be useful if you port a lot of software and cannot
  516. audit all of it and replace or disable fork() usage.
  517. With this option, a program which uses fork() will build
  518. successfully. Of course, it may be useless if fork()
  519. is essential for its operation.
  520. config UCLIBC_HAS_SHADOW
  521. bool "Shadow Password Support"
  522. default y
  523. help
  524. Answer N if you do not need shadow password support.
  525. Most people will answer Y.
  526. config UCLIBC_HAS_PROGRAM_INVOCATION_NAME
  527. bool "Support for program_invocation_name"
  528. default n
  529. help
  530. Support for the GNU-specific program_invocation_name and
  531. program_invocation_short_name strings. Some GNU packages
  532. (like tar and coreutils) utilize these for extra useful
  533. output, but in general are not required.
  534. At startup, these external strings are automatically set
  535. up based on the value of ARGV[0].
  536. If unsure, just answer N.
  537. config UCLIBC_HAS___PROGNAME
  538. bool "Support for __progname"
  539. default y
  540. depends on UCLIBC_HAS_PROGRAM_INVOCATION_NAME
  541. help
  542. Some packages (like openssh) like to peek into internal libc
  543. symbols to make their output a bit more user friendly.
  544. At startup, __progname is automatically set up based on the
  545. value of ARGV[0].
  546. If unsure, just answer N.
  547. config UCLIBC_HAS_PTY
  548. bool "Support for pseudo-terminals"
  549. default y
  550. help
  551. This enables support for pseudo-terminals (see man 4 pts
  552. and man 7 pty).
  553. If unsure, just answer Y.
  554. config ASSUME_DEVPTS
  555. bool "Assume that /dev/pts is a devpts or devfs file system"
  556. default y
  557. depends on UCLIBC_HAS_PTY
  558. help
  559. Enable this if /dev/pts is on a devpts or devfs filesystem. Both
  560. these filesystems automatically manage permissions on the /dev/pts
  561. devices. You may need to mount your devpts or devfs filesystem on
  562. /dev/pts for this to work.
  563. Most people should answer Y.
  564. config UNIX98PTY_ONLY
  565. bool "Support only Unix 98 PTYs"
  566. default y
  567. depends on UCLIBC_HAS_PTY
  568. help
  569. If you want to support only Unix 98 PTYs enable this. Some older
  570. applications may need this disabled and will thus use legacy BSD
  571. style PTY handling which is more complex and also bigger than
  572. Unix 98 PTY handling.
  573. For most current programs, you can generally answer Y.
  574. if UNIX98PTY_ONLY
  575. config UCLIBC_HAS_GETPT
  576. bool "Support getpt() (glibc-compat)"
  577. default n
  578. depends on UCLIBC_HAS_PTY
  579. help
  580. Some packages may need getpt().
  581. All of those are non-standard and can be considered
  582. GNU/libc compatibility.
  583. Either use posix_openpt() or just open /dev/ptmx yourself.
  584. If unsure, just say N.
  585. endif
  586. if !UNIX98PTY_ONLY
  587. # Have to use __libc_ptyname{1,2}[] and related bloat
  588. config UCLIBC_HAS_GETPT
  589. def_bool y
  590. endif
  591. config UCLIBC_HAS_TM_EXTENSIONS
  592. bool "Support 'struct tm' timezone extension fields"
  593. default y
  594. help
  595. Enabling this option adds fields to 'struct tm' in time.h for
  596. tracking the number of seconds east of UTC, and an abbreviation for
  597. the current timezone. These fields are not specified by the SuSv3
  598. standard, but they are commonly used in both GNU and BSD application
  599. code.
  600. To strictly follow the SuSv3 standard, leave this disabled.
  601. Most people will probably want to answer Y.
  602. config UCLIBC_HAS_TZ_CACHING
  603. bool "Enable caching of the last valid timezone 'TZ' string"
  604. default y
  605. help
  606. Answer Y to enable caching of the last valid 'TZ' string describing
  607. the timezone setting. This allows a quick string compare to avoid
  608. repeated parsing of unchanged 'TZ' strings when tzset() is called.
  609. Most people will answer Y.
  610. config UCLIBC_HAS_TZ_FILE
  611. bool "Enable '/etc/TZ' file support to set a default timezone (uClibc-specific)"
  612. default y
  613. help
  614. Answer Y to enable the setting of a default timezone for uClibc.
  615. Ordinarily, uClibc gets the timezone information exclusively from the
  616. 'TZ' environment variable. In particular, there is no support for
  617. the zoneinfo directory tree or the /etc/timezone file used by glibc.
  618. With this option enabled, uClibc will use the value stored in the
  619. file '/etc/TZ' (default path) to obtain timezone information if the
  620. 'TZ' environment variable is missing or has an invalid value. The
  621. file consists of a single line (newline required) of text describing
  622. the timezone in the format specified for the TZ environment variable.
  623. Doing 'echo CST6CDT > /etc/TZ' is enough to create a valid file.
  624. See
  625. http://www.opengroup.org/onlinepubs/007904975/basedefs/xbd_chap08.html
  626. for details on valid settings of 'TZ'.
  627. Most people will answer Y.
  628. config UCLIBC_HAS_TZ_FILE_READ_MANY
  629. bool "Repeatedly read the '/etc/TZ' file"
  630. depends on UCLIBC_HAS_TZ_FILE
  631. default y
  632. help
  633. Answer Y to enable repeated reading of the '/etc/TZ' file even after
  634. a valid value has been read. This incurs the overhead of an
  635. open/read/close for each tzset() call (explicit or implied). However,
  636. setting this will allow applications to update their timezone
  637. information if the contents of the file change.
  638. Most people will answer Y.
  639. config UCLIBC_TZ_FILE_PATH
  640. string "Path to the 'TZ' file for setting the global timezone"
  641. depends on UCLIBC_HAS_TZ_FILE
  642. default "/etc/TZ"
  643. help
  644. This is the path to the 'TZ' file.
  645. Most people will use the default of '/etc/TZ'.
  646. endmenu
  647. menu "Advanced Library Settings"
  648. config UCLIBC_PWD_BUFFER_SIZE
  649. int "Buffer size for getpwnam() and friends"
  650. default 256
  651. range 12 1024
  652. help
  653. This sets the value of the buffer size for getpwnam() and friends.
  654. By default, this is 256. (For reference, glibc uses 1024).
  655. The value can be found using sysconf() with the _SC_GETPW_R_SIZE_MAX
  656. parameter.
  657. config UCLIBC_GRP_BUFFER_SIZE
  658. int "Buffer size for getgrnam() and friends"
  659. default 256
  660. range 12 1024
  661. help
  662. This sets the value of the buffer size for getgrnam() and friends.
  663. By default, this is 256. (For reference, glibc uses 1024).
  664. The value can be found using sysconf() with the _SC_GETGR_R_SIZE_MAX
  665. parameter.
  666. comment "Support various families of functions"
  667. config UCLIBC_LINUX_MODULE_24
  668. bool "Linux kernel module functions"
  669. default !(TARGET_bfin)
  670. help
  671. create_module, query_module
  672. are used in linux (prior to 2.6) for loadable kernel modules.
  673. Say N if you do not use kernel modules, or you only support
  674. Linux 2.6+.
  675. config UCLIBC_LINUX_SPECIFIC
  676. bool "Linux specific functions"
  677. default y
  678. help
  679. capget(), capset(), fstatfs(), inotify_*(), ioperm(), iopl(),
  680. madvise(), modify_ldt(), personality(), prctl()/arch_prctl(),
  681. ppoll(), readahead(), reboot(), remap_file_pages(),
  682. sched_getaffinity(), sched_setaffinity(), sendfile(),
  683. setfsgid(), setfsuid(), setresuid(),
  684. splice(), vmsplice(), tee(), signalfd(), swapoff(), swapon(),
  685. sync_file_range(), sysctl(), sysinfo(), vhangup()
  686. config UCLIBC_HAS_GNU_ERROR
  687. bool "Support GNU extensions for error-reporting"
  688. default y
  689. help
  690. Support for the GNU-specific error(), error_at_line(),
  691. void (* error_print_progname)(), error_message_count
  692. functions and variables. Some GNU packages
  693. utilize these for extra useful output, but in general
  694. are not required.
  695. If unsure, just answer N.
  696. config UCLIBC_BSD_SPECIFIC
  697. bool "BSD specific functions"
  698. default y
  699. help
  700. mincore(), getdomainname(), setdomainname()
  701. If unsure, say N.
  702. config UCLIBC_HAS_BSD_ERR
  703. bool "BSD err functions"
  704. default y
  705. help
  706. These functions are non-standard BSD extensions.
  707. err(), errx(), warn(), warnx(), verr(), verrx(), vwarn(), vwarnx()
  708. If unsure, say N.
  709. config UCLIBC_HAS_OBSOLETE_BSD_SIGNAL
  710. bool "BSD obsolete signal functions"
  711. default n
  712. help
  713. These functions are provided as a compatibility interface for
  714. programs that make use of the historical System V signal API.
  715. This API is obsolete:
  716. new applications should use the POSIX signal API (sigaction(2),
  717. sigprocmask(2), etc.).
  718. Affected functions:
  719. sigset(), sighold(), sigrelse(), sigignore()
  720. If unsure, say N.
  721. config UCLIBC_HAS_OBSOLETE_SYSV_SIGNAL
  722. bool "SYSV obsolete signal functions"
  723. default n
  724. help
  725. Use of sysv_signal() should be avoided; use sigaction(2) instead.
  726. If unsure, say N.
  727. config UCLIBC_NTP_LEGACY
  728. bool "ntp_*() aliases"
  729. default n
  730. help
  731. Provide legacy aliases for ntp functions:
  732. ntp_adjtime(), ntp_gettime()
  733. It is safe to say N here.
  734. config UCLIBC_SV4_DEPRECATED
  735. bool "Enable SVr4 deprecated functions"
  736. default n
  737. help
  738. These functions are DEPRECATED in System V release 4.
  739. Say N unless you desparately need one of the functions below:
  740. ustat() [use statfs(2) in your code instead]
  741. config UCLIBC_HAS_REALTIME
  742. bool "Realtime-related family of SUSv functions"
  743. default y
  744. help
  745. These functions are part of the Timers option and need not
  746. be available on all implementations.
  747. Includes AIO, message-queue, scheduler, semaphore functions:
  748. aio.h
  749. mqueue.h
  750. sched.h
  751. semaphore.h
  752. aio_cancel()
  753. aio_error()
  754. aio_fsync()
  755. aio_read()
  756. lio_listio()
  757. aio_return()
  758. aio_suspend()
  759. aio_write()
  760. clock_getres(), clock_gettime(), clock_settime()
  761. fdatasync()
  762. mlockall(), munlockall()
  763. mlock(), munlock()
  764. mq_close()
  765. mq_getattr()
  766. mq_notify()
  767. mq_open()
  768. mq_receive()
  769. mq_send()
  770. mq_setattr()
  771. mq_unlink()
  772. nanosleep()
  773. sched_getparam()
  774. sched_get_priority_max(), sched_get_priority_min()
  775. sched_getscheduler()
  776. sched_rr_get_interval()
  777. sched_setparam()
  778. sched_setscheduler()
  779. sem_close()
  780. sem_destroy()
  781. sem_getvalue()
  782. sem_init()
  783. sem_open()
  784. sem_post()
  785. sem_trywait(), sem_wait()
  786. sem_unlink()
  787. sigqueue()
  788. sigtimedwait(), sigwaitinfo()
  789. timer_create()
  790. timer_delete()
  791. timer_getoverrun(), timer_gettime(), timer_settime()
  792. config UCLIBC_HAS_ADVANCED_REALTIME
  793. bool "Advanced realtime-related family of SUSv functions"
  794. default y
  795. depends on UCLIBC_HAS_REALTIME
  796. help
  797. These functions are part of the Timers option and need not
  798. be available on all implementations.
  799. clock_getcpuclockid()
  800. clock_nanosleep()
  801. mq_timedreceive()
  802. mq_timedsend()
  803. posix_fadvise()
  804. posix_fallocate()
  805. posix_madvise()
  806. posix_memalign()
  807. posix_mem_offset()
  808. posix_spawnattr_destroy(), posix_spawnattr_init()
  809. posix_spawnattr_getflags(), posix_spawnattr_setflags()
  810. posix_spawnattr_getpgroup(), posix_spawnattr_setpgroup()
  811. posix_spawnattr_getschedparam(), posix_spawnattr_setschedparam()
  812. posix_spawnattr_getschedpolicy(), posix_spawnattr_setschedpolicy()
  813. posix_spawnattr_getsigdefault(), posix_spawnattr_setsigdefault()
  814. posix_spawnattr_getsigmask(), posix_spawnattr_setsigmask()
  815. posix_spawn_file_actions_addclose()
  816. posix_spawn_file_actions_adddup2()
  817. posix_spawn_file_actions_addopen()
  818. posix_spawn_file_actions_destroy()
  819. posix_spawn_file_actions_init()
  820. posix_spawn()
  821. posix_spawnp()
  822. posix_typed_mem_get_info()
  823. pthread_mutex_timedlock()
  824. sem_timedwait()
  825. #config UCLIBC_HAS_TERMIOS
  826. # bool "termios functions"
  827. # default y
  828. # help
  829. # Get and set terminal attributes, line control, get and set baud
  830. # rate.
  831. # termios(), tcgetattr(), tcsetattr(), tcsendbreak(), tcdrain(),
  832. # tcflush(), tcflow(), cfmakeraw(), cfgetospeed(), cfgetispeed(),
  833. # cfsetispeed(), cfsetospeed(), cfsetspeed()
  834. #
  835. # If unsure, say Y.
  836. config UCLIBC_HAS_EPOLL
  837. bool "epoll"
  838. default y
  839. help
  840. epoll_create(), epoll_ctl(), epoll_wait() functions.
  841. config UCLIBC_HAS_XATTR
  842. bool "Extended Attributes"
  843. default y
  844. help
  845. Extended Attributes support.
  846. setxattr()
  847. lsetxattr()
  848. fsetxattr()
  849. getxattr()
  850. lgetxattr()
  851. fgetxattr()
  852. listxattr()
  853. llistxattr()
  854. flistxattr()
  855. removexattr()
  856. lremovexattr()
  857. fremovexattr()
  858. Say N unless you need support for extended attributes and the
  859. filesystems do actually support them.
  860. config UCLIBC_HAS_PROFILING
  861. bool "Profiling support"
  862. default y
  863. help
  864. gcc's -finstrument-functions needs these.
  865. Most people can safely answer N.
  866. config UCLIBC_HAS_CRYPT_IMPL
  867. bool "libcrypt support"
  868. default y
  869. help
  870. libcrypt contains crypt(), setkey() and encrypt()
  871. config UCLIBC_HAS_CRYPT_STUB
  872. bool "libcrypt stubs"
  873. default y
  874. depends on !UCLIBC_HAS_CRYPT_IMPL
  875. help
  876. Standards mandate that crypt(3) provides a stub if it is unavailable.
  877. If you enable this option then stubs for
  878. crypt(), setkey() and encrypt()
  879. will be provided in a small libcrypt.
  880. config UCLIBC_HAS_CRYPT
  881. def_bool y
  882. depends on UCLIBC_HAS_CRYPT_IMPL || UCLIBC_HAS_CRYPT_STUB
  883. endmenu
  884. menuconfig UCLIBC_HAS_NETWORK_SUPPORT
  885. bool "Networking Support"
  886. default y
  887. help
  888. Say N here if you do not need network support.
  889. if UCLIBC_HAS_NETWORK_SUPPORT
  890. config UCLIBC_HAS_SOCKET
  891. bool "Socket support"
  892. default y
  893. help
  894. If you want to include support for sockets then answer Y.
  895. config UCLIBC_HAS_IPV4
  896. bool "IP version 4 support"
  897. default y
  898. select UCLIBC_HAS_SOCKET
  899. help
  900. If you want to include support for the Internet Protocol
  901. (IP version 4) then answer Y.
  902. Most people will say Y.
  903. config UCLIBC_HAS_IPV6
  904. bool "IP version 6 support"
  905. default n
  906. select UCLIBC_HAS_SOCKET
  907. help
  908. If you want to include support for the next version of the Internet
  909. Protocol (IP version 6) then answer Y.
  910. Most people should answer N.
  911. config UCLIBC_HAS_RPC
  912. bool "Remote Procedure Call (RPC) support"
  913. default n
  914. # RPC+socket-ipvX doesn't currently work.
  915. depends on UCLIBC_HAS_IPV4 || UCLIBC_HAS_IPV6
  916. help
  917. If you want to include RPC support, enable this. RPC is rarely used
  918. for anything except for the NFS filesystem. Unless you plan to use
  919. NFS, you can probably leave this set to N and save some space.
  920. If you need to use NFS then you should answer Y.
  921. config UCLIBC_HAS_FULL_RPC
  922. bool "Full RPC support"
  923. depends on UCLIBC_HAS_RPC
  924. default y if !HAVE_SHARED
  925. help
  926. Normally we enable just enough RPC support for things like rshd and
  927. nfs mounts to work. If you find you need the rest of the RPC stuff,
  928. then enable this option. Most people can safely answer N.
  929. config UCLIBC_HAS_REENTRANT_RPC
  930. bool "Reentrant RPC support"
  931. depends on UCLIBC_HAS_RPC
  932. default y if !HAVE_SHARED
  933. help
  934. Most packages utilize the normal (non-reentrant) RPC functions, but
  935. some (like exportfs from nfs-utils) need these reentrant versions.
  936. Most people can safely answer N.
  937. config UCLIBC_USE_NETLINK
  938. bool "Use netlink to query interfaces"
  939. default n
  940. depends on UCLIBC_HAS_SOCKET
  941. help
  942. In newer versions of Linux (2.4.17+), support was added for querying
  943. network device information via netlink rather than the old style
  944. ioctl's. Most of the time, the older ioctl style is sufficient (and
  945. it is smaller than netlink), but if you find that not all of your
  946. devices are being returned by the if_nameindex() function, you will
  947. have to use the netlink implementation.
  948. Most people can safely answer N.
  949. config UCLIBC_SUPPORT_AI_ADDRCONFIG
  950. bool "Support the AI_ADDRCONFIG flag"
  951. depends on UCLIBC_USE_NETLINK
  952. default n
  953. help
  954. The implementation of AI_ADDRCONFIG is aligned with the glibc
  955. implementation using netlink to query interfaces to find both
  956. ipv4 and ipv6 support. This is only needed if an application uses
  957. the AI_ADDRCONFIG flag.
  958. Most people can safely answer N.
  959. config UCLIBC_HAS_BSD_RES_CLOSE
  960. bool "Support res_close() (bsd-compat)"
  961. default n
  962. help
  963. Answer Y if you desperately want to support BSD compatibility in
  964. the network code.
  965. Most people will say N.
  966. config UCLIBC_HAS_COMPAT_RES_STATE
  967. bool "Use compatible but bloated _res"
  968. default y
  969. help
  970. Answer Y if you build network utilities and they muck with resolver
  971. internals a lot (_res global structure). uclibc does not use most
  972. of _res.XXX fields, and with this option OFF they won't even exist.
  973. Which will make e.g. dig build fail.
  974. Answering N saves around 400 bytes in bss.
  975. config UCLIBC_HAS_EXTRA_COMPAT_RES_STATE
  976. bool "Use extra compatible but extra bloated _res"
  977. default n
  978. help
  979. Answer Y if selecting UCLIBC_HAS_COMPAT_RES_STATE is not enough.
  980. As far as I can say, this should never be needed.
  981. config UCLIBC_HAS_RESOLV_STUB
  982. bool "Provide libresolv stub"
  983. default n
  984. help
  985. Provide a dummy resolv library.
  986. endif
  987. menu "String and Stdio Support"
  988. config UCLIBC_HAS_STRING_GENERIC_OPT
  989. bool "Use faster (but larger) generic string functions"
  990. default y
  991. help
  992. Answer Y to use the (tweaked) glibc generic string functions.
  993. In general, they are faster (but 3-5K larger) than the base
  994. uClibc string functions which are optimized solely for size.
  995. Many people will answer Y.
  996. config UCLIBC_HAS_STRING_ARCH_OPT
  997. bool "Use arch-specific assembly string functions (where available)"
  998. default y
  999. help
  1000. Answer Y to use any archtecture-specific assembly language string
  1001. functions available for this target plaform.
  1002. Note that assembly implementations are not available for all string
  1003. functions, so some generic (written in C) string functions may
  1004. still be used.
  1005. These are small and fast, the only reason _not_ to say Y here is
  1006. for debugging purposes.
  1007. config UCLIBC_HAS_CTYPE_TABLES
  1008. bool "Use Table Versions Of 'ctype.h' Functions."
  1009. default y
  1010. help
  1011. Answer Y to use table versions of the 'ctype.h' functions.
  1012. While the non-table versions are often smaller when building
  1013. statically linked apps, they work only in stub locale mode.
  1014. Most people will answer Y.
  1015. config UCLIBC_HAS_CTYPE_SIGNED
  1016. bool "Support Signed Characters In 'ctype.h' Functions."
  1017. depends on UCLIBC_HAS_CTYPE_TABLES
  1018. default y
  1019. help
  1020. Answer Y to enable support for passing signed char values to
  1021. the 'ctype.h' functions. ANSI/ISO C99 and SUSv3 specify that
  1022. these functions are only defined for unsigned char values and
  1023. EOF. However, glibc allows negative signed char values as well
  1024. in order to support 'broken old programs'.
  1025. Most people will answer Y.
  1026. choice
  1027. prompt "ctype argument checking"
  1028. depends on UCLIBC_HAS_CTYPE_TABLES
  1029. default UCLIBC_HAS_CTYPE_UNSAFE
  1030. help
  1031. Please select the invalid arg behavior you want for the 'ctype'
  1032. functions.
  1033. The 'ctype' functions are now implemented using table lookups, with
  1034. the arg being the index. This can result in incorrect memory accesses
  1035. or even segfaults for args outside of the allowed range.
  1036. NOTE: This only affects the 'ctype' _functions_. It does not affect
  1037. the macro implementations.
  1038. config UCLIBC_HAS_CTYPE_UNSAFE
  1039. bool "Do not check -- unsafe"
  1040. config UCLIBC_HAS_CTYPE_CHECKED
  1041. bool "Detect and handle appropriately"
  1042. config UCLIBC_HAS_CTYPE_ENFORCED
  1043. bool "Issue a diagnostic and abort()"
  1044. endchoice
  1045. config UCLIBC_HAS_WCHAR
  1046. bool "Wide Character Support"
  1047. default n
  1048. help
  1049. Answer Y to enable wide character support. This will make uClibc
  1050. much larger. It is also currently required for locale support.
  1051. Most people will answer N.
  1052. config UCLIBC_HAS_LOCALE
  1053. bool "Locale Support"
  1054. select UCLIBC_HAS_WCHAR
  1055. select UCLIBC_HAS_CTYPE_TABLES
  1056. default n
  1057. help
  1058. uClibc now has full ANSI/ISO C99 locale support (except for
  1059. wcsftime() and collating items in regex). Be aware that enabling
  1060. this option will make uClibc much larger.
  1061. Enabling UCLIBC_HAS_LOCALE with the default set of supported locales
  1062. (169 UTF-8 locales, and 144 locales for other codesets) will enlarge
  1063. uClibc by around 300k. You can reduce this size by building your own
  1064. custom set of locate data (see extra/locale/LOCALES for details).
  1065. uClibc's locale support is still under development. For example,
  1066. codesets using shift states are not currently supported. Support is
  1067. planned in the next iteration of locale support.
  1068. Answer Y to enable locale support. Most people will answer N.
  1069. config UCLIBC_PREGENERATED_LOCALE_DATA
  1070. bool "Use Pre-generated Locale Data"
  1071. depends on UCLIBC_HAS_LOCALE
  1072. default n
  1073. help
  1074. Use pre-built locale data.
  1075. Note that these pregenerated locales are sensitive to your
  1076. target architecture (endianess, bitcount).
  1077. Saying N here is highly recommended.
  1078. config UCLIBC_DOWNLOAD_PREGENERATED_LOCALE_DATA
  1079. bool "Automagically Download the Pre-generated Locale Data (if necessary)"
  1080. depends on UCLIBC_PREGENERATED_LOCALE_DATA
  1081. default n
  1082. help
  1083. If you would like the build process to use 'wget' to automatically
  1084. download the pregenerated locale data, enable this option. Otherwise
  1085. you will need to obtain the locale data yourself from:
  1086. http://www.uclibc.org/downloads/uClibc-locale-*.tgz
  1087. and place the uClibc-locale-*.tgz tarball in the extra/locale/
  1088. directory.
  1089. Go ahead and make life easy for yourself... Answer Y.
  1090. config UCLIBC_HAS_XLOCALE
  1091. bool "Extended Locale Support (experimental/incomplete)"
  1092. depends on UCLIBC_HAS_LOCALE
  1093. default n
  1094. help
  1095. Answer Y to enable extended locale support similar to that provided
  1096. by glibc. This is primarily intended to support libstd++
  1097. functionality.
  1098. However, it also allows thread-specific locale selection via
  1099. uselocale().
  1100. Most people will answer N.
  1101. config UCLIBC_HAS_HEXADECIMAL_FLOATS
  1102. bool "Support hexadecimal float notation"
  1103. depends on UCLIBC_HAS_CTYPE_TABLES
  1104. depends on UCLIBC_HAS_FLOATS
  1105. default n
  1106. help
  1107. Answer Y to enable support for hexadecimal float notation in the
  1108. (wchar and) char string to floating point conversion functions, as
  1109. well as support for the %a and %A conversion specifiers in the
  1110. *printf() and *scanf() functions.
  1111. Most people will answer N.
  1112. config UCLIBC_HAS_GLIBC_DIGIT_GROUPING
  1113. bool "Support glibc's \"'\" flag for allowing locale-specific digit grouping"
  1114. depends on UCLIBC_HAS_LOCALE
  1115. depends on UCLIBC_HAS_FLOATS
  1116. default n
  1117. help
  1118. Answer Y to enable support for glibc's \"'\" flag for allowing
  1119. locale-specific digit grouping in base 10 integer conversions and
  1120. appropriate floating point conversions in the *printf() and *scanf()
  1121. functions.
  1122. Most people will answer N.
  1123. config UCLIBC_HAS_SCANF_LENIENT_DIGIT_GROUPING
  1124. bool "Do not require digit grouping when the \"'\" flag is specified"
  1125. depends on UCLIBC_HAS_GLIBC_DIGIT_GROUPING
  1126. default y
  1127. help
  1128. Answer Y to make digit grouping optional when the \"'\" flag is
  1129. specified.
  1130. This is the standard glibc behavior. If the initial string of digits
  1131. exceeds the maximum group number, the input will be treated as a
  1132. normal non-grouped number.
  1133. Most people will answer N.
  1134. config UCLIBC_HAS_GLIBC_CUSTOM_PRINTF
  1135. bool "Support glibc's register_printf_function() (glibc-compat)"
  1136. depends on !USE_OLD_VFPRINTF
  1137. default n
  1138. help
  1139. Answer Y to support glibc's register_printf_function() to allow an
  1140. application to add its own printf conversion specifiers.
  1141. NOTE: Limits the number or registered specifiers to 10.
  1142. NOTE: Requires new conversion specifiers to be ASCII
  1143. characters (0-0x7f). This is to avoid problems with processing
  1144. format strings in locales with different multibyte conversions.
  1145. Most people will answer N.
  1146. config USE_OLD_VFPRINTF
  1147. bool "Use the old vfprintf implementation"
  1148. depends on !UCLIBC_HAS_WCHAR
  1149. default n
  1150. help
  1151. Set to true to use the old vfprintf instead of the new. This is
  1152. roughly C89 compliant with some extensions, and is much smaller.
  1153. However, it does not support wide chars, positional args, or glibc
  1154. custom printf specifiers.
  1155. Most people will answer N.
  1156. config UCLIBC_PRINTF_SCANF_POSITIONAL_ARGS
  1157. int "Maximum number of positional args. Either 0 or >= 9."
  1158. depends on !USE_OLD_VFPRINTF
  1159. default 9
  1160. help
  1161. Set the maximum number of positional args supported by the
  1162. printf/scanf functions. The Single Unix Specification Version 3
  1163. requires a minimum value of 9. Setting this to a value lower than
  1164. 9 will disable positional arg support and cause the NL_ARGMAX macro
  1165. in limits.h to be #undef'd.
  1166. WARNING! The workspace to support positional args is currently
  1167. allocated on the stack. You probably don't want to set
  1168. this to too high a value.
  1169. Most people will answer 9.
  1170. config UCLIBC_HAS_SCANF_GLIBC_A_FLAG
  1171. bool "Support glibc's 'a' flag for scanf string conversions (not implemented)"
  1172. default n
  1173. help
  1174. NOTE!!! Currently Not Implemented!!! Just A Place Holder!! NOTE!!!
  1175. NOTE!!! Conflicts with an ANSI/ISO C99 scanf flag!! NOTE!!!
  1176. Answer Y to enable support for glibc's 'a' flag for the scanf string
  1177. conversions '%s', '%[', '%ls', '%l[', and '%S'. This is used to
  1178. auto-allocate sufficient memory to hold the data retrieved.
  1179. Most people will answer N.
  1180. choice
  1181. prompt "Stdio buffer size"
  1182. default UCLIBC_HAS_STDIO_BUFSIZ_4096
  1183. help
  1184. Please select a value for BUFSIZ. This will be used by the
  1185. stdio subsystem as the default buffer size for a file, and
  1186. affects fopen(), setvbuf(), etc.
  1187. NOTE: Setting this to 'none' will disable buffering completely.
  1188. However, BUFSIZ will still be defined in stdio.h as 256 because
  1189. many applications use this value.
  1190. config UCLIBC_HAS_STDIO_BUFSIZ_NONE
  1191. bool "none (WARNING - BUFSIZ will be 256 in stdio.h)"
  1192. depends on !UCLIBC_HAS_WCHAR
  1193. config UCLIBC_HAS_STDIO_BUFSIZ_256
  1194. bool "256 (minimum ANSI/ISO C99 value)"
  1195. config UCLIBC_HAS_STDIO_BUFSIZ_512
  1196. bool "512"
  1197. config UCLIBC_HAS_STDIO_BUFSIZ_1024
  1198. bool "1024"
  1199. config UCLIBC_HAS_STDIO_BUFSIZ_2048
  1200. bool "2048"
  1201. config UCLIBC_HAS_STDIO_BUFSIZ_4096
  1202. bool "4096"
  1203. config UCLIBC_HAS_STDIO_BUFSIZ_8192
  1204. bool "8192"
  1205. # If you add more choices, you will need to update uClibc_stdio.h.
  1206. endchoice
  1207. choice
  1208. prompt "Stdio builtin buffer size (uClibc-specific)"
  1209. depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
  1210. default UCLIBC_HAS_STDIO_BUILTIN_BUFFER_NONE
  1211. help
  1212. When a FILE is created with fopen(), an attempt is made to allocate
  1213. a BUFSIZ buffer for it. If the allocation fails, fopen() will still
  1214. succeed but the FILE will be unbuffered.
  1215. This option adds a small amount of space to each FILE to act as an
  1216. emergency buffer in the event of a buffer allocation failure.
  1217. Most people will answer None.
  1218. config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_NONE
  1219. bool "None"
  1220. config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_4
  1221. bool "4"
  1222. config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_8
  1223. bool "8"
  1224. # If you add more choices, you will need to update uClibc_stdio.h.
  1225. endchoice
  1226. config UCLIBC_HAS_STDIO_SHUTDOWN_ON_ABORT
  1227. bool "Attempt to shutdown stdio subsystem when abort() is called."
  1228. default n
  1229. help
  1230. ANSI/ISO C99 requires abort() to be asyn-signal-safe. So there was
  1231. a behavioral change made in SUSv3. Previously, abort() was required
  1232. to have the affect of fclose() on all open streams. The wording has
  1233. been changed to "may" from "shall".
  1234. Most people will answer N.
  1235. config UCLIBC_HAS_STDIO_GETC_MACRO
  1236. bool "Provide a macro version of getc()"
  1237. depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
  1238. default y
  1239. help
  1240. Provide a macro version of getc().
  1241. Most people will answer Y.
  1242. config UCLIBC_HAS_STDIO_PUTC_MACRO
  1243. bool "Provide a macro version of putc()"
  1244. depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
  1245. default y
  1246. help
  1247. Provide a macro version of putc().
  1248. Most people will answer Y.
  1249. config UCLIBC_HAS_STDIO_AUTO_RW_TRANSITION
  1250. bool "Support auto-r/w transition"
  1251. default y
  1252. help
  1253. Answer Y to enable the stdio subsystem to automaticly transition
  1254. between reading and writing. This relaxes the ANSI/ISO C99
  1255. requirement:
  1256. When a file is opened with update mode ('+' as the second or third
  1257. character in the list of mode argument values), both input and output
  1258. may be performed on the associated stream. However, output shall not
  1259. be directly followed by input without an intervening call to the
  1260. fflush function or to a file positioning function (fseek, fsetpos,
  1261. or rewind), and input shall not be directly followed by output without
  1262. an intervening call to a file positioning function, unless the input
  1263. operation encounters end­of­file.
  1264. Most people will answer Y.
  1265. config UCLIBC_HAS_FOPEN_LARGEFILE_MODE
  1266. bool "Support an fopen() 'F' flag for large file mode (uClibc-specific)"
  1267. depends on UCLIBC_HAS_LFS
  1268. default n
  1269. help
  1270. Answer Y to enable a uClibc-specific extension to allow passing an
  1271. additional 'F' flag in the mode string for fopen() to specify that
  1272. the file should be open()ed with the O_LARGEFILE flag set.
  1273. Most people will answer N.
  1274. config UCLIBC_HAS_FOPEN_EXCLUSIVE_MODE
  1275. bool "Support an fopen() 'x' flag for exclusive mode (glibc-compat)"
  1276. default n
  1277. help
  1278. Answer Y to support a glibc extension to allow passing
  1279. additional 'x' flag in the mode string for fopen() to specify that
  1280. the file should be open()ed with the O_EXCL flag set.
  1281. Most people will answer N.
  1282. config UCLIBC_HAS_GLIBC_CUSTOM_STREAMS
  1283. bool "Support fmemopen(), open_memstream(), and fopencookie() (glibc-compat)"
  1284. default n
  1285. help
  1286. Answer Y to support the glibc 'custom stream' extension functions
  1287. fmemopen(), open_memstream(), and fopencookie().
  1288. NOTE: There are some minor differences regarding seeking behavior.
  1289. Most people will answer N.
  1290. config UCLIBC_HAS_PRINTF_M_SPEC
  1291. bool "Support the '%m' specifier in printf format strings (glibc-compat)"
  1292. default n
  1293. help
  1294. Answer Y to support a glibc extension to interpret '%m' in printf
  1295. format strings as an instruction to output the error message string
  1296. (as generated by strerror) corresponding to the current value of
  1297. 'errno'.
  1298. Most people will answer N.
  1299. config UCLIBC_HAS_ERRNO_MESSAGES
  1300. bool "Include the errno message text in the library"
  1301. default y
  1302. help
  1303. Answer Y if you want to include the errno message text in the
  1304. library. This adds about 3K to the library, but enables strerror()
  1305. to generate text other than 'Unknown error <number>'.
  1306. Most people will answer Y.
  1307. config UCLIBC_HAS_SYS_ERRLIST
  1308. bool "Support sys_errlist[] (obsolete-compat)"
  1309. depends on UCLIBC_HAS_ERRNO_MESSAGES
  1310. default n
  1311. help
  1312. Answer Y if you want to support the obsolete sys_errlist[].
  1313. This adds about 0.5k to the library, except for the mips
  1314. arch where it adds over 4K.
  1315. WARNING! In the future, support for sys_errlist[] may be unavailable
  1316. in at least some configurations. In fact, it may be removed
  1317. altogether.
  1318. Most people will answer N.
  1319. Application writers: use the strerror(3) function.
  1320. config UCLIBC_HAS_SIGNUM_MESSAGES
  1321. bool "Include the signum message text in the library"
  1322. default y
  1323. help
  1324. Answer Y if you want to include the signum message text in the
  1325. library. This adds about 0.5K to the library, but enables strsignal()
  1326. to generate text other than 'Unknown signal <number>'.
  1327. Most people will answer Y.
  1328. config UCLIBC_HAS_SYS_SIGLIST
  1329. bool "Support sys_siglist[] (bsd-compat)"
  1330. depends on UCLIBC_HAS_SIGNUM_MESSAGES
  1331. default n
  1332. help
  1333. Answer Y if you want to support sys_siglist[].
  1334. WARNING! In the future, support for sys_siglist[] may be unavailable
  1335. in at least some configurations. In fact, it may be removed
  1336. altogether.
  1337. Most people will answer N.
  1338. config UCLIBC_HAS_GETTEXT_AWARENESS
  1339. bool "Include gettext awareness"
  1340. depends on UCLIBC_HAS_LOCALE && UCLIBC_MJN3_ONLY
  1341. default n
  1342. help
  1343. NOTE!!! Not yet integrated with strerror and strsignal. NOTE!!!
  1344. Answer Y if you want to include weak stub gettext support and
  1345. make the *strerror*() and strsignal() functions gettext-aware.
  1346. Currently, to get functional gettext functionality you will need
  1347. to use gnu gettext.
  1348. Most people will answer N.
  1349. config UCLIBC_HAS_GNU_GETOPT
  1350. bool "Support gnu getopt"
  1351. default y
  1352. help
  1353. Answer Y if you want to include full gnu getopt() instead of a
  1354. (much smaller) SUSv3 compatible getopt().
  1355. Most people will answer Y.
  1356. config UCLIBC_HAS_STDIO_FUTEXES
  1357. bool "Use futexes for multithreaded I/O locking"
  1358. default n
  1359. depends on UCLIBC_HAS_THREADS_NATIVE
  1360. help
  1361. If you want to compile uClibc to use futexes for low-level
  1362. I/O locking, answer Y. Otherwise, answer N.
  1363. config UCLIBC_HAS_GETOPT_LONG
  1364. bool "Support getopt_long/getopt_long_only"
  1365. depends on !UCLIBC_HAS_GNU_GETOPT
  1366. default y
  1367. help
  1368. Answer Y if you want to include getopt_long[_only() used by many
  1369. apps, even busybox.
  1370. Most people will answer Y.
  1371. config UCLIBC_HAS_GNU_GETSUBOPT
  1372. bool "Support glibc getsubopt"
  1373. default y
  1374. help
  1375. Answer Y if you want to include glibc getsubopt() instead of a
  1376. smaller SUSv3 compatible getsubopt().
  1377. Most people will answer Y.
  1378. endmenu
  1379. menu "Big and Tall"
  1380. config UCLIBC_HAS_REGEX
  1381. bool "Regular Expression Support"
  1382. default y
  1383. help
  1384. POSIX regular expression code is really big -- 53k all by itself.
  1385. If you don't use regular expressions, turn this off and save space.
  1386. Of course, if you only statically link, leave this on, since it will
  1387. only be included in your apps if you use regular expressions.
  1388. config UCLIBC_HAS_REGEX_OLD
  1389. bool "Use the older (stable) regular expression code"
  1390. depends on UCLIBC_HAS_REGEX
  1391. default y
  1392. help
  1393. There are two versions of regex. The older (stable) version has
  1394. been in uClibc for quite a long time but hasn't seen too many
  1395. updates. It also has some known issues when dealing with uncommon
  1396. corner cases and multibyte/unicode strings. However, it is quite
  1397. a bit smaller than the newer version.
  1398. If the older version has worked for you and you don't need unicode
  1399. support, then stick with the old version (and say Y here).
  1400. Otherwise, you should use the new version (and say N here).
  1401. config UCLIBC_HAS_FNMATCH
  1402. bool "fnmatch Support"
  1403. default y
  1404. help
  1405. POSIX fnmatch.
  1406. config UCLIBC_HAS_FNMATCH_OLD
  1407. bool "Use the older (stable) fnmatch code"
  1408. depends on UCLIBC_HAS_FNMATCH
  1409. default y
  1410. help
  1411. There are two versions of fnmatch. The older (stable) version has
  1412. been in uClibc for quite a long time but hasn't seen too many
  1413. updates. It also has some known issues when dealing with uncommon
  1414. corner cases and multibyte/unicode strings. However, it is quite
  1415. a bit smaller than the newer version.
  1416. If the older version has worked for you and you don't need unicode
  1417. support, then stick with the old version (and say Y here).
  1418. Otherwise, you should use the new version (and say N here).
  1419. config UCLIBC_HAS_WORDEXP
  1420. bool "Support the wordexp() interface"
  1421. depends on UCLIBC_HAS_GLOB
  1422. default n
  1423. help
  1424. The SuSv3 wordexp() interface performs word expansions per the Shell
  1425. and Utilities volume of IEEE Std 1003.1-2001, Section 2.6. It is
  1426. intended for use by applications that want to implement all of the
  1427. standard Bourne shell expansions on input data.
  1428. This interface is rarely used, and very large. Unless you have a
  1429. pressing need for wordexp(), you should probably answer N.
  1430. config UCLIBC_HAS_FTW
  1431. bool "Support the ftw() and nftw() interfaces"
  1432. default n
  1433. help
  1434. The SuSv3 ftw() and nftw() interfaces are used to recursively descend
  1435. directory paths while repeatedly calling a function.
  1436. This interface is rarely used, and adds around 4.5k. Unless you have
  1437. a pressing need for ftw() or nftw(), you should probably answer N.
  1438. config UCLIBC_HAS_GLOB
  1439. bool "Support the glob() interface"
  1440. depends on UCLIBC_HAS_FNMATCH
  1441. default y
  1442. help
  1443. The glob interface is somewhat large (weighing in at about 2,5k). It
  1444. is used fairly often, but is an option since people wanting to go for
  1445. absolute minimum size may wish to omit it.
  1446. Most people will answer Y.
  1447. config UCLIBC_HAS_GNU_GLOB
  1448. bool "Support gnu glob() interface"
  1449. depends on UCLIBC_HAS_GLOB
  1450. default n
  1451. help
  1452. The gnu glob interface is somewhat larger (weighing in at about 4,2k)
  1453. than it's SuSv3 counterpart (and is out of date). It is an old copy
  1454. from glibc and does not support all the GNU specific options.
  1455. Answer Y if you want to include full gnu glob() instead of the smaller
  1456. SUSv3 compatible glob().
  1457. Most people will answer N.
  1458. endmenu
  1459. menu "Library Installation Options"
  1460. config SHARED_LIB_LOADER_PREFIX
  1461. string "Shared library loader path"
  1462. depends on HAVE_SHARED
  1463. default "$(RUNTIME_PREFIX)lib"
  1464. help
  1465. When using shared libraries, this path is the location where the
  1466. shared library will be invoked. This value will be compiled into
  1467. every binary compiled with uClibc.
  1468. For a typical target system this should be set to "/lib", such that
  1469. 'make install' will install /lib/ld-uClibc.so.0.
  1470. BIG FAT WARNING:
  1471. If you do not have a shared library loader with the correct name
  1472. sitting in the directory this points to, your binaries will not
  1473. run.
  1474. config RUNTIME_PREFIX
  1475. string "uClibc runtime library directory"
  1476. default "/usr/$(TARGET_ARCH)-linux-uclibc/"
  1477. help
  1478. RUNTIME_PREFIX is the directory into which the uClibc runtime
  1479. libraries will be installed. The result will look something
  1480. like the following:
  1481. $(RUNTIME_PREFIX)/
  1482. lib/ <contains all runtime libraries>
  1483. usr/bin/ldd <the ldd utility program>
  1484. sbin/ldconfig <the ldconfig utility program>
  1485. This value is used by the 'make install' Makefile target. Since this
  1486. directory is compiled into the shared library loader, you will need to
  1487. recompile uClibc if you change this value...
  1488. For a typical target system this should be set to "/", such that
  1489. 'make install' will install /lib/libuClibc-<VERSION>.so
  1490. config DEVEL_PREFIX
  1491. string "uClibc development environment directory"
  1492. default "/usr/$(TARGET_ARCH)-linux-uclibc/usr/"
  1493. help
  1494. DEVEL_PREFIX is the directory into which the uClibc development
  1495. environment will be installed. The result will look something
  1496. like the following:
  1497. $(DEVEL_PREFIX)/
  1498. lib/ <contains static libs>
  1499. include/ <Where all the header files go>
  1500. This value is used by the 'make install' Makefile target when
  1501. installing a uClibc development environment.
  1502. For a typical target system this should be set to "/usr", such that
  1503. 'make install' will install /usr/include/<header files>.
  1504. config HARDWIRED_ABSPATH
  1505. bool "Hardwire absolute paths into linker scripts"
  1506. default y
  1507. help
  1508. This prepends absolute paths to the libraries mentioned in linker
  1509. scripts such as libc.so.
  1510. This is a build time optimization. It has no impact on dynamic
  1511. linking at runtime, which doesn't use linker scripts.
  1512. You must disable this to use uClibc with a relocatable toolchain,
  1513. such as the prebuilt binary cross compilers at
  1514. http://uclibc.org/downloads/binaries which may be installed at an
  1515. arbitrary location (such as in a user's home directory).
  1516. The amount of time saved by this optimization is actually too small to
  1517. measure. The linker just had to search the library path to find the
  1518. linker script, so the dentries are cache hot if it has to search the
  1519. same path again. But it's what glibc does, so we do it too.
  1520. endmenu
  1521. menu "Security options"
  1522. config UCLIBC_BUILD_PIE
  1523. bool "Build utilities as ET_DYN/PIE executables"
  1524. depends on HAVE_SHARED
  1525. depends on TARGET_arm || TARGET_frv || TARGET_i386 || TARGET_mips || TARGET_powerpc
  1526. select FORCE_SHAREABLE_TEXT_SEGMENTS
  1527. default n
  1528. help
  1529. If you answer Y here, ldd and iconv are built as ET_DYN/PIE
  1530. executables.
  1531. It requires gcc-3.4 and binutils-2.15 (for arm 2.16) or later.
  1532. More about ET_DYN/PIE binaries on <http://pax.grsecurity.net/> .
  1533. WARNING: This option also enables FORCE_SHAREABLE_TEXT_SEGMENTS, so
  1534. all libraries have to be built with -fPIC or -fpic, and all
  1535. assembler functions must be written as position independent
  1536. code (PIC).
  1537. config UCLIBC_HAS_ARC4RANDOM
  1538. bool "Include the arc4random() function"
  1539. default n
  1540. help
  1541. Answer Y to support the OpenBSD-like arc4random() function. This
  1542. function picks a random number between 0 and N, and will always return
  1543. something even if the random driver is dead. If urandom fails then
  1544. gettimeofday(2) will be used as the random seed. This function is
  1545. designed to be more dependable than invoking /dev/urandom directly.
  1546. OpenSSL and OpenNTPD currently support this function.
  1547. Most people will answer N.
  1548. config HAVE_NO_SSP
  1549. bool
  1550. default n
  1551. config UCLIBC_HAS_SSP
  1552. bool "Support for GCC stack smashing protector"
  1553. depends on !HAVE_NO_SSP
  1554. default n
  1555. help
  1556. Add code to support GCC's -fstack-protector[-all] option to uClibc.
  1557. This requires GCC 4.1 or newer. GCC does not have to provide libssp,
  1558. the needed functions are added to ldso/libc instead.
  1559. GCC's stack protector is a reimplementation of IBM's propolice.
  1560. See http://www.trl.ibm.com/projects/security/ssp/ and
  1561. http://www.linuxfromscratch.org/hints/downloads/files/ssp.txt
  1562. for details.
  1563. Note that NOEXECSTACK on a kernel with address space randomization
  1564. is generally sufficient to prevent most buffer overflow exploits
  1565. without increasing code size. This option essentially adds debugging
  1566. code to catch them.
  1567. Most people will answer N.
  1568. config UCLIBC_HAS_SSP_COMPAT
  1569. bool "Support for gcc-3.x propolice smashing stack protector"
  1570. depends on UCLIBC_HAS_SSP
  1571. default n
  1572. help
  1573. Add gcc-3.x propolice smashing stack protector to the library.
  1574. This requires a patched version of GCC, supporting the
  1575. -fstack-protector[-all] options, with the __guard and
  1576. __stack_smash_handler functions removed from libgcc.
  1577. These functions are added to ldso/libc instead.
  1578. More information at:
  1579. <http://www.research.ibm.com/trl/projects/security/ssp/>
  1580. Most people will answer N.
  1581. config SSP_QUICK_CANARY
  1582. bool "Use simple guard values without accessing /dev/urandom"
  1583. depends on UCLIBC_HAS_SSP
  1584. default n
  1585. help
  1586. Use gettimeofday(2) to define the __guard without accessing
  1587. /dev/urandom.
  1588. WARNING: This makes smashing stack protector vulnerable to timing
  1589. attacks.
  1590. Most people will answer N.
  1591. choice
  1592. prompt "Propolice protection blocking signal"
  1593. depends on UCLIBC_HAS_SSP
  1594. default PROPOLICE_BLOCK_ABRT if ! DODEBUG
  1595. default PROPOLICE_BLOCK_SEGV if DODEBUG
  1596. help
  1597. "abort" use SIGABRT to block offending programs.
  1598. This is the default implementation.
  1599. "segfault" use SIGSEGV to block offending programs.
  1600. Use this for debugging.
  1601. If unsure, answer "abort".
  1602. config PROPOLICE_BLOCK_ABRT
  1603. bool "abort"
  1604. config PROPOLICE_BLOCK_SEGV
  1605. bool "segfault"
  1606. endchoice
  1607. config UCLIBC_BUILD_SSP
  1608. bool "Build uClibc with -fstack-protector"
  1609. depends on UCLIBC_HAS_SSP
  1610. default n
  1611. help
  1612. Build all uClibc libraries and executables with -fstack-protector,
  1613. adding extra stack overflow checking to most uClibc functions.
  1614. config UCLIBC_BUILD_RELRO
  1615. bool "Build uClibc with linker option -z RELRO"
  1616. depends on HAVE_SHARED
  1617. default y
  1618. help
  1619. Build all libraries and executables with "ld -z relro".
  1620. This tells the linker to mark chunks of an executable or shared
  1621. library read-only after applying dynamic relocations. (This comes
  1622. up when a global const variable is initialized to the address of a
  1623. function or the value of another global variable.)
  1624. This is a fairly obscure option the ld man page doesn't even bother
  1625. to document properly. It's a security paranoia issue that's more
  1626. likely to consume memory (by allocating an extra page) rather than
  1627. save it.
  1628. This is explained in more depth at
  1629. http://www.airs.com/blog/archives/189
  1630. Nobody is likely to care whether you say Y or N here.
  1631. config UCLIBC_BUILD_NOW
  1632. bool "Build uClibc with linker option -z NOW"
  1633. depends on HAVE_SHARED
  1634. default n
  1635. help
  1636. Build all libraries and executables with "ld -z now".
  1637. This tells the linker to resolve all symbols when the library is
  1638. first loaded, rather than when each function is first called. This
  1639. increases start-up latency by a few microseconds and may do
  1640. unnecessary work (resolving symbols that are never used), but the
  1641. realtime people like it for making microbenchmark timings slightly
  1642. more predictable and in some cases it can be slightly faster due to
  1643. CPU cache behavior (not having to fault the linker back in to do
  1644. lazy symbol resolution).
  1645. Most people can't tell the difference between selecting Y or N here.
  1646. config UCLIBC_BUILD_NOEXECSTACK
  1647. bool "Build uClibc with noexecstack marking"
  1648. default y
  1649. help
  1650. Mark all assembler files as noexecstack, which will mark uClibc
  1651. as not requiring an executable stack. (This doesn't prevent other
  1652. files you link against from claiming to need an executable stack, it
  1653. just won't cause uClibc to request it unnecessarily.)
  1654. This is a security thing to make buffer overflows harder to exploit.
  1655. By itself, it's kind of useless, as Linus Torvalds explained in 1998:
  1656. http://old.lwn.net/1998/0806/a/linus-noexec.html
  1657. It only actually provides any security when combined with address
  1658. space randomization, explained here: http://lwn.net/Articles/121845/
  1659. Address space randomization is on by default in current linux
  1660. kernels (although it can be disabled using the option
  1661. CONFIG_COMPAT_BRK).
  1662. You should probably say Y.
  1663. endmenu
  1664. menu "uClibc development/debugging options"
  1665. config CROSS_COMPILER_PREFIX
  1666. string "Cross-compiling toolchain prefix"
  1667. default ""
  1668. help
  1669. The prefix used to execute your cross-compiling toolchain. For
  1670. example, if you run 'arm-linux-uclibc-gcc' to compile something,
  1671. then enter 'arm-linux-uclibc-' here.
  1672. config UCLIBC_EXTRA_CFLAGS
  1673. string "Enter any extra CFLAGS to use to build uClibc"
  1674. default ""
  1675. help
  1676. Add any additional CFLAGS to be used to build uClibc.
  1677. config DODEBUG
  1678. bool "Build uClibc with debugging symbols"
  1679. default n
  1680. select EXTRA_WARNINGS
  1681. help
  1682. Say Y here if you wish to compile uClibc with debugging symbols.
  1683. This will allow you to use a debugger to examine uClibc internals
  1684. while applications are running. This increases the size of the
  1685. library considerably and should only be used when doing development.
  1686. If you are doing development and want to debug uClibc, answer Y.
  1687. Otherwise, answer N.
  1688. config DODEBUG_PT
  1689. bool "Build pthread with debugging output"
  1690. depends on UCLIBC_HAS_THREADS && LINUXTHREADS_OLD
  1691. default n
  1692. help
  1693. Enable debug output in libpthread. This is only useful when doing
  1694. development in libpthread itself.
  1695. Otherwise, answer N.
  1696. config DOSTRIP
  1697. bool "Strip libraries and executables"
  1698. default y
  1699. depends on !DODEBUG
  1700. help
  1701. Say Y here if you do wish to strip all uClibc libraries and
  1702. executables. No stripping increases the size of the binaries
  1703. considerably, but makes it possible to debug uClibc libraries.
  1704. Most people will answer Y.
  1705. config DOASSERTS
  1706. bool "Build uClibc with run-time assertion testing"
  1707. default n
  1708. help
  1709. Say Y here to include runtime assertion tests.
  1710. This enables runtime assertion testing in some code, which can
  1711. increase the size of the library and incur runtime overhead.
  1712. If you say N, then this testing will be disabled.
  1713. config SUPPORT_LD_DEBUG
  1714. bool "Build the shared library loader with debugging support"
  1715. depends on HAVE_SHARED
  1716. default n
  1717. help
  1718. Answer Y here to enable all the extra code needed to debug the uClibc
  1719. native shared library loader. The level of debugging noise that is
  1720. generated depends on the LD_DEBUG environment variable... Just set
  1721. LD_DEBUG to something like: 'LD_DEBUG=token1,token2,.. prog' to
  1722. debug your application. Diagnostic messages will then be printed to
  1723. the stderr.
  1724. For now these debugging tokens are available:
  1725. detail provide more information for some options
  1726. move display copy processing
  1727. symbols display symbol table processing
  1728. reloc display relocation processing; detail shows the
  1729. relocation patch
  1730. nofixups never fixes up jump relocations
  1731. bindings displays the resolve processing (function calls);
  1732. detail shows the relocation patch
  1733. all Enable everything!
  1734. The additional environment variable:
  1735. LD_DEBUG_OUTPUT=file
  1736. redirects the diagnostics to an output file created using
  1737. the specified name and the process id as a suffix.
  1738. An excellent start is simply:
  1739. $ LD_DEBUG=binding,move,symbols,reloc,detail ./appname
  1740. or to log everything to a file named 'logfile', try this
  1741. $ LD_DEBUG=all LD_DEBUG_OUTPUT=logfile ./appname
  1742. If you are doing development and want to debug uClibc's shared library
  1743. loader, answer Y. Mere mortals answer N.
  1744. config SUPPORT_LD_DEBUG_EARLY
  1745. bool "Build the shared library loader with early debugging support"
  1746. depends on HAVE_SHARED
  1747. default n
  1748. help
  1749. Answer Y here to if you find the uClibc shared library loader is
  1750. crashing or otherwise not working very early on. This is typical
  1751. only when starting a new port when you haven't figured out how to
  1752. properly get the values for argc, argv, environ, etc. This method
  1753. allows a degree of visibility into the very early shared library
  1754. loader initialization process. If you are doing development and want
  1755. to debug the uClibc shared library loader early initialization,
  1756. answer Y. Mere mortals answer N.
  1757. config UCLIBC_MALLOC_DEBUGGING
  1758. bool "Build malloc with debugging support"
  1759. depends on MALLOC || MALLOC_STANDARD
  1760. default n
  1761. help
  1762. Answer Y here to compile extra debugging support code into malloc.
  1763. Malloc debugging output may then be enabled at runtime using the
  1764. MALLOC_DEBUG environment variable.
  1765. The value of MALLOC_DEBUG should be an integer, which is interpreted
  1766. as a bitmask with the following bits:
  1767. 1 - do extra consistency checking
  1768. 2 - output messages for malloc/free calls and OS
  1769. allocation calls
  1770. 4 - output messages for the `MMB' layer
  1771. 8 - output messages for internal malloc heap manipulation
  1772. calls
  1773. Because this increases the size of malloc appreciably (due to strings
  1774. etc), you should say N unless you need to debug a malloc problem.
  1775. config WARNINGS
  1776. string "Compiler Warnings"
  1777. default "-Wall"
  1778. help
  1779. Set this to the set of gcc warnings you wish to see while compiling.
  1780. config EXTRA_WARNINGS
  1781. bool "Enable extra annoying warnings"
  1782. default n
  1783. help
  1784. If you wish to build with extra warnings enabled, say Y here.
  1785. config DOMULTI
  1786. bool "Compile all sources at once into an object"
  1787. default n
  1788. help
  1789. Set this to compile all sources at once into an object (IMA).
  1790. This mode of compilation uses alot of memory but may produce
  1791. smaller binaries.
  1792. Note that you need a very recent GCC for this to work, like
  1793. gcc >= 4.3 plus eventually some patches.
  1794. If unsure, keep the default of N.
  1795. config UCLIBC_MJN3_ONLY
  1796. bool "Manuel's hidden warnings"
  1797. default n
  1798. help
  1799. Answer Y here to see all Manuel's personal notes, warnings, and todos.
  1800. Most people will answer N.
  1801. endmenu