Config.in 68 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. choice
  307. prompt "Thread support"
  308. #default UCLIBC_HAS_THREADS_NATIVE if (TARGET_alpha || TARGET_arm || TARGET_i386 || TARGET_mips || TARGET_powerpc || TARGET_sh || TARGET_sh64)
  309. default HAS_NO_THREADS
  310. help
  311. If you want to compile uClibc with pthread support, then answer Y.
  312. This will increase the size of uClibc by adding a bunch of locking
  313. to critical data structures, and adding extra code to ensure that
  314. functions are properly reentrant.
  315. config HAS_NO_THREADS
  316. bool "none"
  317. help
  318. Disable thread support.
  319. config LINUXTHREADS_OLD
  320. bool "older (stable) version of linuxthreads"
  321. # linuxthreads and linuxthreads.old need nanosleep()
  322. select UCLIBC_HAS_REALTIME
  323. help
  324. There are two versions of linuxthreads. The older (stable) version
  325. has been in uClibc for quite a long time but hasn't seen too many
  326. updates other than bugfixes.
  327. config LINUXTHREADS_NEW
  328. bool "slightly newer version of linuxthreads"
  329. help
  330. The new version has not been tested much, and lacks ports for arches
  331. which glibc does not support (like bfin/frv/etc...), but is based on
  332. the latest code from glibc, so it may be the only choice for the
  333. newer ports (like alpha/amd64/64bit arches and hppa).
  334. config UCLIBC_HAS_THREADS_NATIVE
  335. bool "Native POSIX Threading (NPTL)"
  336. select UCLIBC_HAS_TLS
  337. help
  338. If you want to compile uClibc with NPTL support, then answer Y.
  339. IMPORTANT NOTE! NPTL requires a Linux 2.6 kernel, binutils
  340. at least version 2.16 and GCC with at least version 4.1.0. NPTL
  341. will not work with older versions of any above sources. If you
  342. ignore any of these guidelines, you do so at your own risk. Do
  343. not ask for help on any of the development mailing lists.
  344. !!!! WARNING !!!! BIG FAT WARNING !!!! REALLY BIG FAT WARNING !!!!
  345. This is experimental code and at times it may not even build and
  346. even if it does it might decide to do random damage. This code is
  347. potentially hazardous to your health and sanity. It will remain
  348. that way until further notice at which point this notice will
  349. disappear. Thank you for your support and for not smoking.
  350. endchoice
  351. config UCLIBC_HAS_THREADS
  352. def_bool y if !HAS_NO_THREADS
  353. config UCLIBC_HAS_TLS
  354. bool "Thread-Local Storage"
  355. depends on UCLIBC_HAS_THREADS_NATIVE
  356. default n
  357. help
  358. If you want to enable TLS support then answer Y.
  359. This is fast an efficient way to store per-thread local data
  360. which is not on stack. It needs __thread support enabled in
  361. gcc.
  362. config PTHREADS_DEBUG_SUPPORT
  363. bool "Build pthreads debugging support"
  364. default n
  365. depends on UCLIBC_HAS_THREADS
  366. help
  367. Say Y here if you wish to be able to debug applications that use
  368. uClibc's pthreads library. By enabling this option, a library
  369. named libthread_db will be built. This library will be dlopen()'d
  370. by gdb and will allow gdb to debug the threads in your application.
  371. IMPORTANT NOTE! Because gdb must dlopen() the libthread_db library,
  372. you must compile gdb with uClibc in order for pthread debugging to
  373. work properly.
  374. If you are doing development and want to debug applications using
  375. uClibc's pthread library, answer Y. Otherwise, answer N.
  376. config UCLIBC_HAS_SYSLOG
  377. bool "Syslog support"
  378. default y
  379. depends on UCLIBC_HAS_NETWORK_SUPPORT
  380. select UCLIBC_HAS_SOCKET
  381. help
  382. Support sending messages to the system logger.
  383. This requires socket-support.
  384. config UCLIBC_HAS_LFS
  385. bool "Large File Support"
  386. default y
  387. help
  388. If you wish to build uClibc with support for accessing large files
  389. (i.e. files greater then 2 GiB) then answer Y. Do not enable this
  390. if you are using an older Linux kernel (2.0.x) that lacks large file
  391. support. Enabling this option will increase the size of uClibc.
  392. choice
  393. prompt "Malloc Implementation"
  394. default MALLOC if ! ARCH_USE_MMU
  395. default MALLOC_STANDARD if ARCH_USE_MMU
  396. config MALLOC
  397. bool "malloc"
  398. help
  399. "malloc" use mmap for all allocations and so works very well on
  400. MMU-less systems that do not support the brk() system call. It is
  401. pretty smart about reusing already allocated memory, and minimizing
  402. memory wastage.
  403. This is the default for uClinux MMU-less systems.
  404. config MALLOC_SIMPLE
  405. bool "malloc-simple"
  406. help
  407. "malloc-simple" is trivially simple and slow as molasses. It
  408. was written from scratch for uClibc, and is the simplest possible
  409. (and therefore smallest) malloc implementation.
  410. This uses only the mmap() system call to allocate and free memory,
  411. and does not use the brk() system call at all, making it a fine
  412. choice for MMU-less systems with very limited memory. It's 100%
  413. standards compliant, thread safe, very small, and releases freed
  414. memory back to the OS immediately rather than keeping it in the
  415. process's heap for reallocation. It is also VERY SLOW.
  416. config MALLOC_STANDARD
  417. bool "malloc-standard"
  418. depends on ARCH_USE_MMU
  419. help
  420. "malloc-standard" is derived from the public domain dlmalloc
  421. implementation by Doug Lea. It is quite fast, and is pretty smart
  422. about reusing already allocated memory, and minimizing memory
  423. wastage. This uses brk() for small allocations, while using mmap()
  424. for larger allocations. This is the default malloc implementation
  425. for uClibc.
  426. If unsure, answer "malloc-standard".
  427. endchoice
  428. config MALLOC_GLIBC_COMPAT
  429. bool "Malloc returns live pointer for malloc(0)"
  430. default n
  431. help
  432. The behavior of malloc(0) is listed as implementation-defined by
  433. SuSv3. Glibc returns a valid pointer to something, while uClibc
  434. normally returns NULL. I personally feel glibc's behavior is
  435. not particularly safe, and allows buggy applications to hide very
  436. serious problems.
  437. When this option is enabled, uClibc will act just like glibc, and
  438. return a live pointer when someone calls malloc(0). This pointer
  439. provides a malloc'ed area with a size of 1 byte. This feature is
  440. mostly useful when dealing with applications using autoconf's broken
  441. AC_FUNC_MALLOC macro (which redefines malloc as rpl_malloc if it
  442. does not detect glibc style returning-a-valid-pointer-for-malloc(0)
  443. behavior). Most people can safely answer N.
  444. config UCLIBC_DYNAMIC_ATEXIT
  445. bool "Dynamic atexit() Support"
  446. default y
  447. help
  448. When this option is enabled, uClibc will support an infinite number,
  449. of atexit() and on_exit() functions, limited only by your available
  450. memory. This can be important when uClibc is used with C++, since
  451. global destructors are implemented via atexit(), and it is quite
  452. possible to exceed the default number when this option is disabled.
  453. Enabling this option adds a few bytes, and more significantly makes
  454. atexit and on_exit depend on malloc, which can be bad when compiling
  455. static executables.
  456. Unless you use uClibc with C++, you should probably answer N.
  457. config COMPAT_ATEXIT
  458. bool "Old (visible) atexit Support"
  459. default n
  460. help
  461. Enable this option if you want to update from 0.9.28 to git/0.9.29,
  462. else you will be missing atexit() until you rebuild all apps.
  463. config UCLIBC_SUSV3_LEGACY
  464. bool "Enable SuSv3 LEGACY functions"
  465. default n
  466. #vfork,
  467. # h_errno
  468. # gethostbyaddr
  469. # gethostbyname
  470. help
  471. Enable this option if you want to have SuSv3 LEGACY functions
  472. in the library, else they are replaced by SuSv3 proposed macros.
  473. Currently applies to:
  474. bcmp, bcopy, bzero, index, rindex, ftime,
  475. bsd_signal, (ecvt), (fcvt), gcvt, (getcontext),
  476. (getwd), (makecontext),
  477. mktemp, (pthread_attr_getstackaddr), (pthread_attr_setstackaddr),
  478. scalb, (setcontext), (swapcontext), ualarm, usleep,
  479. wcswcs.
  480. WARNING! ABI incompatibility.
  481. config UCLIBC_SUSV3_LEGACY_MACROS
  482. bool "Enable SuSv3 LEGACY macros"
  483. default n
  484. help
  485. Enable this option if you want to have SuSv3 LEGACY macros.
  486. Currently applies to bcopy/bzero/bcmp/index/rindex et al.
  487. WARNING! ABI incompatibility.
  488. config UCLIBC_SUSV4_LEGACY
  489. bool "Enable SuSv4 LEGACY or obsolescent functions"
  490. default n
  491. help
  492. Enable this option if you want to have SuSv4 LEGACY functions
  493. and macros in the library.
  494. Currently applies to:
  495. - XSI functions:
  496. _longjmp, _setjmp, _tolower, _toupper, ftw, getitimer,
  497. gettimeofday, isascii, pthread_getconcurrency,
  498. pthread_setconcurrency, setitimer, setpgrp, sighold,
  499. sigignore, sigpause, sigrelse, sigset, siginterrupt,
  500. tempnam, toascii, ulimit.
  501. - Base functions:
  502. asctime, asctime_r, ctime, ctime_r, gets, rand_r,
  503. tmpnam, utime.
  504. WARNING! ABI incompatibility.
  505. config UCLIBC_HAS_STUBS
  506. bool "Provide stubs for unavailable functionality"
  507. default n
  508. help
  509. With this option uClibc provides non-functional stubs for
  510. functions which are impossible to implement on the target
  511. architecture. Otherwise, such functions are simply omitted.
  512. As of 2008-07, this option makes uClibc provide fork() stub
  513. on NOMMU targets. It always sets errno to ENOSYS and returns -1.
  514. This may be useful if you port a lot of software and cannot
  515. audit all of it and replace or disable fork() usage.
  516. With this option, a program which uses fork() will build
  517. successfully. Of course, it may be useless if fork()
  518. is essential for its operation.
  519. config UCLIBC_HAS_SHADOW
  520. bool "Shadow Password Support"
  521. default y
  522. help
  523. Answer N if you do not need shadow password support.
  524. Most people will answer Y.
  525. config UCLIBC_HAS_PROGRAM_INVOCATION_NAME
  526. bool "Support for program_invocation_name"
  527. default n
  528. help
  529. Support for the GNU-specific program_invocation_name and
  530. program_invocation_short_name strings. Some GNU packages
  531. (like tar and coreutils) utilize these for extra useful
  532. output, but in general are not required.
  533. At startup, these external strings are automatically set
  534. up based on the value of ARGV[0].
  535. If unsure, just answer N.
  536. config UCLIBC_HAS___PROGNAME
  537. bool "Support for __progname"
  538. default y
  539. depends on UCLIBC_HAS_PROGRAM_INVOCATION_NAME
  540. help
  541. Some packages (like openssh) like to peek into internal libc
  542. symbols to make their output a bit more user friendly.
  543. At startup, __progname is automatically set up based on the
  544. value of ARGV[0].
  545. If unsure, just answer N.
  546. config UCLIBC_HAS_PTY
  547. bool "Support for pseudo-terminals"
  548. default y
  549. help
  550. This enables support for pseudo-terminals (see man 4 pts
  551. and man 7 pty).
  552. If unsure, just answer Y.
  553. config ASSUME_DEVPTS
  554. bool "Assume that /dev/pts is a devpts or devfs file system"
  555. default y
  556. depends on UCLIBC_HAS_PTY
  557. help
  558. Enable this if /dev/pts is on a devpts or devfs filesystem. Both
  559. these filesystems automatically manage permissions on the /dev/pts
  560. devices. You may need to mount your devpts or devfs filesystem on
  561. /dev/pts for this to work.
  562. Most people should answer Y.
  563. config UNIX98PTY_ONLY
  564. bool "Support only Unix 98 PTYs"
  565. default y
  566. depends on UCLIBC_HAS_PTY
  567. help
  568. If you want to support only Unix 98 PTYs enable this. Some older
  569. applications may need this disabled and will thus use legacy BSD
  570. style PTY handling which is more complex and also bigger than
  571. Unix 98 PTY handling.
  572. For most current programs, you can generally answer Y.
  573. if UNIX98PTY_ONLY
  574. config UCLIBC_HAS_GETPT
  575. bool "Support getpt() (glibc-compat)"
  576. default n
  577. depends on UCLIBC_HAS_PTY
  578. help
  579. Some packages may need getpt().
  580. All of those are non-standard and can be considered
  581. GNU/libc compatibility.
  582. Either use posix_openpt() or just open /dev/ptmx yourself.
  583. If unsure, just say N.
  584. endif
  585. if !UNIX98PTY_ONLY
  586. # Have to use __libc_ptyname{1,2}[] and related bloat
  587. config UCLIBC_HAS_GETPT
  588. def_bool y
  589. endif
  590. config UCLIBC_HAS_TM_EXTENSIONS
  591. bool "Support 'struct tm' timezone extension fields"
  592. default y
  593. help
  594. Enabling this option adds fields to 'struct tm' in time.h for
  595. tracking the number of seconds east of UTC, and an abbreviation for
  596. the current timezone. These fields are not specified by the SuSv3
  597. standard, but they are commonly used in both GNU and BSD application
  598. code.
  599. To strictly follow the SuSv3 standard, leave this disabled.
  600. Most people will probably want to answer Y.
  601. config UCLIBC_HAS_TZ_CACHING
  602. bool "Enable caching of the last valid timezone 'TZ' string"
  603. default y
  604. help
  605. Answer Y to enable caching of the last valid 'TZ' string describing
  606. the timezone setting. This allows a quick string compare to avoid
  607. repeated parsing of unchanged 'TZ' strings when tzset() is called.
  608. Most people will answer Y.
  609. config UCLIBC_HAS_TZ_FILE
  610. bool "Enable '/etc/TZ' file support to set a default timezone (uClibc-specific)"
  611. default y
  612. help
  613. Answer Y to enable the setting of a default timezone for uClibc.
  614. Ordinarily, uClibc gets the timezone information exclusively from the
  615. 'TZ' environment variable. In particular, there is no support for
  616. the zoneinfo directory tree or the /etc/timezone file used by glibc.
  617. With this option enabled, uClibc will use the value stored in the
  618. file '/etc/TZ' (default path) to obtain timezone information if the
  619. 'TZ' environment variable is missing or has an invalid value. The
  620. file consists of a single line (newline required) of text describing
  621. the timezone in the format specified for the TZ environment variable.
  622. Doing 'echo CST6CDT > /etc/TZ' is enough to create a valid file.
  623. See
  624. http://www.opengroup.org/onlinepubs/007904975/basedefs/xbd_chap08.html
  625. for details on valid settings of 'TZ'.
  626. Most people will answer Y.
  627. config UCLIBC_HAS_TZ_FILE_READ_MANY
  628. bool "Repeatedly read the '/etc/TZ' file"
  629. depends on UCLIBC_HAS_TZ_FILE
  630. default y
  631. help
  632. Answer Y to enable repeated reading of the '/etc/TZ' file even after
  633. a valid value has been read. This incurs the overhead of an
  634. open/read/close for each tzset() call (explicit or implied). However,
  635. setting this will allow applications to update their timezone
  636. information if the contents of the file change.
  637. Most people will answer Y.
  638. config UCLIBC_TZ_FILE_PATH
  639. string "Path to the 'TZ' file for setting the global timezone"
  640. depends on UCLIBC_HAS_TZ_FILE
  641. default "/etc/TZ"
  642. help
  643. This is the path to the 'TZ' file.
  644. Most people will use the default of '/etc/TZ'.
  645. endmenu
  646. menu "Advanced Library Settings"
  647. config UCLIBC_PWD_BUFFER_SIZE
  648. int "Buffer size for getpwnam() and friends"
  649. default 256
  650. range 12 1024
  651. help
  652. This sets the value of the buffer size for getpwnam() and friends.
  653. By default, this is 256. (For reference, glibc uses 1024).
  654. The value can be found using sysconf() with the _SC_GETPW_R_SIZE_MAX
  655. parameter.
  656. config UCLIBC_GRP_BUFFER_SIZE
  657. int "Buffer size for getgrnam() and friends"
  658. default 256
  659. range 12 1024
  660. help
  661. This sets the value of the buffer size for getgrnam() and friends.
  662. By default, this is 256. (For reference, glibc uses 1024).
  663. The value can be found using sysconf() with the _SC_GETGR_R_SIZE_MAX
  664. parameter.
  665. comment "Support various families of functions"
  666. config UCLIBC_LINUX_MODULE_24
  667. bool "Linux kernel module functions"
  668. default !(TARGET_bfin)
  669. help
  670. create_module, query_module
  671. are used in linux (prior to 2.6) for loadable kernel modules.
  672. Say N if you do not use kernel modules, or you only support
  673. Linux 2.6+.
  674. config UCLIBC_LINUX_SPECIFIC
  675. bool "Linux specific functions"
  676. default y
  677. help
  678. capget(), capset(), fstatfs(), inotify_*(), ioperm(), iopl(),
  679. madvise(), modify_ldt(), personality(), prctl()/arch_prctl(),
  680. ppoll(), readahead(), reboot(), remap_file_pages(),
  681. sched_getaffinity(), sched_setaffinity(), sendfile(),
  682. setfsgid(), setfsuid(), setresuid(),
  683. splice(), vmsplice(), tee(), signalfd(), swapoff(), swapon(),
  684. sync_file_range(), sysctl(), sysinfo(), vhangup()
  685. config UCLIBC_HAS_GNU_ERROR
  686. bool "Support GNU extensions for error-reporting"
  687. default y
  688. help
  689. Support for the GNU-specific error(), error_at_line(),
  690. void (* error_print_progname)(), error_message_count
  691. functions and variables. Some GNU packages
  692. utilize these for extra useful output, but in general
  693. are not required.
  694. If unsure, just answer N.
  695. config UCLIBC_BSD_SPECIFIC
  696. bool "BSD specific functions"
  697. default y
  698. help
  699. mincore(), getdomainname(), setdomainname()
  700. If unsure, say N.
  701. config UCLIBC_HAS_BSD_ERR
  702. bool "BSD err functions"
  703. default y
  704. help
  705. These functions are non-standard BSD extensions.
  706. err(), errx(), warn(), warnx(), verr(), verrx(), vwarn(), vwarnx()
  707. If unsure, say N.
  708. config UCLIBC_HAS_OBSOLETE_BSD_SIGNAL
  709. bool "BSD obsolete signal functions"
  710. default n
  711. help
  712. These functions are provided as a compatibility interface for
  713. programs that make use of the historical System V signal API.
  714. This API is obsolete:
  715. new applications should use the POSIX signal API (sigaction(2),
  716. sigprocmask(2), etc.).
  717. Affected functions:
  718. sigset(), sighold(), sigrelse(), sigignore()
  719. If unsure, say N.
  720. config UCLIBC_HAS_OBSOLETE_SYSV_SIGNAL
  721. bool "SYSV obsolete signal functions"
  722. default n
  723. help
  724. Use of sysv_signal() should be avoided; use sigaction(2) instead.
  725. If unsure, say N.
  726. config UCLIBC_NTP_LEGACY
  727. bool "ntp_*() aliases"
  728. default n
  729. help
  730. Provide legacy aliases for ntp functions:
  731. ntp_adjtime(), ntp_gettime()
  732. It is safe to say N here.
  733. config UCLIBC_SV4_DEPRECATED
  734. bool "Enable SVr4 deprecated functions"
  735. default n
  736. help
  737. These functions are DEPRECATED in System V release 4.
  738. Say N unless you desparately need one of the functions below:
  739. ustat() [use statfs(2) in your code instead]
  740. config UCLIBC_HAS_REALTIME
  741. bool "Realtime-related family of SUSv functions"
  742. default y
  743. help
  744. These functions are part of the Timers option and need not
  745. be available on all implementations.
  746. Includes AIO, message-queue, scheduler, semaphore functions:
  747. aio.h
  748. mqueue.h
  749. sched.h
  750. semaphore.h
  751. aio_cancel()
  752. aio_error()
  753. aio_fsync()
  754. aio_read()
  755. lio_listio()
  756. aio_return()
  757. aio_suspend()
  758. aio_write()
  759. clock_getres(), clock_gettime(), clock_settime()
  760. fdatasync()
  761. mlockall(), munlockall()
  762. mlock(), munlock()
  763. mq_close()
  764. mq_getattr()
  765. mq_notify()
  766. mq_open()
  767. mq_receive()
  768. mq_send()
  769. mq_setattr()
  770. mq_unlink()
  771. nanosleep()
  772. sched_getparam()
  773. sched_get_priority_max(), sched_get_priority_min()
  774. sched_getscheduler()
  775. sched_rr_get_interval()
  776. sched_setparam()
  777. sched_setscheduler()
  778. sem_close()
  779. sem_destroy()
  780. sem_getvalue()
  781. sem_init()
  782. sem_open()
  783. sem_post()
  784. sem_trywait(), sem_wait()
  785. sem_unlink()
  786. sigqueue()
  787. sigtimedwait(), sigwaitinfo()
  788. timer_create()
  789. timer_delete()
  790. timer_getoverrun(), timer_gettime(), timer_settime()
  791. config UCLIBC_HAS_ADVANCED_REALTIME
  792. bool "Advanced realtime-related family of SUSv functions"
  793. default y
  794. depends on UCLIBC_HAS_REALTIME
  795. help
  796. These functions are part of the Timers option and need not
  797. be available on all implementations.
  798. clock_getcpuclockid()
  799. clock_nanosleep()
  800. mq_timedreceive()
  801. mq_timedsend()
  802. posix_fadvise()
  803. posix_fallocate()
  804. posix_madvise()
  805. posix_memalign()
  806. posix_mem_offset()
  807. posix_spawnattr_destroy(), posix_spawnattr_init()
  808. posix_spawnattr_getflags(), posix_spawnattr_setflags()
  809. posix_spawnattr_getpgroup(), posix_spawnattr_setpgroup()
  810. posix_spawnattr_getschedparam(), posix_spawnattr_setschedparam()
  811. posix_spawnattr_getschedpolicy(), posix_spawnattr_setschedpolicy()
  812. posix_spawnattr_getsigdefault(), posix_spawnattr_setsigdefault()
  813. posix_spawnattr_getsigmask(), posix_spawnattr_setsigmask()
  814. posix_spawn_file_actions_addclose()
  815. posix_spawn_file_actions_adddup2()
  816. posix_spawn_file_actions_addopen()
  817. posix_spawn_file_actions_destroy()
  818. posix_spawn_file_actions_init()
  819. posix_spawn()
  820. posix_spawnp()
  821. posix_typed_mem_get_info()
  822. pthread_mutex_timedlock()
  823. sem_timedwait()
  824. #config UCLIBC_HAS_TERMIOS
  825. # bool "termios functions"
  826. # default y
  827. # help
  828. # Get and set terminal attributes, line control, get and set baud
  829. # rate.
  830. # termios(), tcgetattr(), tcsetattr(), tcsendbreak(), tcdrain(),
  831. # tcflush(), tcflow(), cfmakeraw(), cfgetospeed(), cfgetispeed(),
  832. # cfsetispeed(), cfsetospeed(), cfsetspeed()
  833. #
  834. # If unsure, say Y.
  835. config UCLIBC_HAS_EPOLL
  836. bool "epoll"
  837. default y
  838. help
  839. epoll_create(), epoll_ctl(), epoll_wait() functions.
  840. config UCLIBC_HAS_XATTR
  841. bool "Extended Attributes"
  842. default y
  843. help
  844. Extended Attributes support.
  845. setxattr()
  846. lsetxattr()
  847. fsetxattr()
  848. getxattr()
  849. lgetxattr()
  850. fgetxattr()
  851. listxattr()
  852. llistxattr()
  853. flistxattr()
  854. removexattr()
  855. lremovexattr()
  856. fremovexattr()
  857. Say N unless you need support for extended attributes and the
  858. filesystems do actually support them.
  859. config UCLIBC_HAS_PROFILING
  860. bool "Profiling support"
  861. default y
  862. help
  863. gcc's -finstrument-functions needs these.
  864. Most people can safely answer N.
  865. config UCLIBC_HAS_CRYPT_IMPL
  866. bool "libcrypt support"
  867. default y
  868. help
  869. libcrypt contains crypt(), setkey() and encrypt()
  870. config UCLIBC_HAS_CRYPT_STUB
  871. bool "libcrypt stubs"
  872. default y
  873. depends on !UCLIBC_HAS_CRYPT_IMPL
  874. help
  875. Standards mandate that crypt(3) provides a stub if it is unavailable.
  876. If you enable this option then stubs for
  877. crypt(), setkey() and encrypt()
  878. will be provided in a small libcrypt.
  879. config UCLIBC_HAS_CRYPT
  880. def_bool y
  881. depends on UCLIBC_HAS_CRYPT_IMPL || UCLIBC_HAS_CRYPT_STUB
  882. endmenu
  883. menuconfig UCLIBC_HAS_NETWORK_SUPPORT
  884. bool "Networking Support"
  885. default y
  886. help
  887. Say N here if you do not need network support.
  888. if UCLIBC_HAS_NETWORK_SUPPORT
  889. config UCLIBC_HAS_SOCKET
  890. bool "Socket support"
  891. default y
  892. help
  893. If you want to include support for sockets then answer Y.
  894. config UCLIBC_HAS_IPV4
  895. bool "IP version 4 support"
  896. default y
  897. select UCLIBC_HAS_SOCKET
  898. help
  899. If you want to include support for the Internet Protocol
  900. (IP version 4) then answer Y.
  901. Most people will say Y.
  902. config UCLIBC_HAS_IPV6
  903. bool "IP version 6 support"
  904. default n
  905. select UCLIBC_HAS_SOCKET
  906. help
  907. If you want to include support for the next version of the Internet
  908. Protocol (IP version 6) then answer Y.
  909. Most people should answer N.
  910. config UCLIBC_HAS_RPC
  911. bool "Remote Procedure Call (RPC) support"
  912. default n
  913. # RPC+socket-ipvX doesn't currently work.
  914. depends on UCLIBC_HAS_IPV4 || UCLIBC_HAS_IPV6
  915. help
  916. If you want to include RPC support, enable this. RPC is rarely used
  917. for anything except for the NFS filesystem. Unless you plan to use
  918. NFS, you can probably leave this set to N and save some space.
  919. If you need to use NFS then you should answer Y.
  920. config UCLIBC_HAS_FULL_RPC
  921. bool "Full RPC support"
  922. depends on UCLIBC_HAS_RPC
  923. default y if !HAVE_SHARED
  924. help
  925. Normally we enable just enough RPC support for things like rshd and
  926. nfs mounts to work. If you find you need the rest of the RPC stuff,
  927. then enable this option. Most people can safely answer N.
  928. config UCLIBC_HAS_REENTRANT_RPC
  929. bool "Reentrant RPC support"
  930. depends on UCLIBC_HAS_RPC
  931. default y if !HAVE_SHARED
  932. help
  933. Most packages utilize the normal (non-reentrant) RPC functions, but
  934. some (like exportfs from nfs-utils) need these reentrant versions.
  935. Most people can safely answer N.
  936. config UCLIBC_USE_NETLINK
  937. bool "Use netlink to query interfaces"
  938. default n
  939. depends on UCLIBC_HAS_SOCKET
  940. help
  941. In newer versions of Linux (2.4.17+), support was added for querying
  942. network device information via netlink rather than the old style
  943. ioctl's. Most of the time, the older ioctl style is sufficient (and
  944. it is smaller than netlink), but if you find that not all of your
  945. devices are being returned by the if_nameindex() function, you will
  946. have to use the netlink implementation.
  947. Most people can safely answer N.
  948. config UCLIBC_SUPPORT_AI_ADDRCONFIG
  949. bool "Support the AI_ADDRCONFIG flag"
  950. depends on UCLIBC_USE_NETLINK
  951. default n
  952. help
  953. The implementation of AI_ADDRCONFIG is aligned with the glibc
  954. implementation using netlink to query interfaces to find both
  955. ipv4 and ipv6 support. This is only needed if an application uses
  956. the AI_ADDRCONFIG flag.
  957. Most people can safely answer N.
  958. config UCLIBC_HAS_BSD_RES_CLOSE
  959. bool "Support res_close() (bsd-compat)"
  960. default n
  961. help
  962. Answer Y if you desperately want to support BSD compatibility in
  963. the network code.
  964. Most people will say N.
  965. config UCLIBC_HAS_COMPAT_RES_STATE
  966. bool "Use compatible but bloated _res"
  967. default y
  968. help
  969. Answer Y if you build network utilities and they muck with resolver
  970. internals a lot (_res global structure). uclibc does not use most
  971. of _res.XXX fields, and with this option OFF they won't even exist.
  972. Which will make e.g. dig build fail.
  973. Answering N saves around 400 bytes in bss.
  974. config UCLIBC_HAS_EXTRA_COMPAT_RES_STATE
  975. bool "Use extra compatible but extra bloated _res"
  976. default n
  977. help
  978. Answer Y if selecting UCLIBC_HAS_COMPAT_RES_STATE is not enough.
  979. As far as I can say, this should never be needed.
  980. config UCLIBC_HAS_RESOLV_STUB
  981. bool "Provide libresolv stub"
  982. default n
  983. help
  984. Provide a dummy resolv library.
  985. endif
  986. menu "String and Stdio Support"
  987. config UCLIBC_HAS_STRING_GENERIC_OPT
  988. bool "Use faster (but larger) generic string functions"
  989. default y
  990. help
  991. Answer Y to use the (tweaked) glibc generic string functions.
  992. In general, they are faster (but 3-5K larger) than the base
  993. uClibc string functions which are optimized solely for size.
  994. Many people will answer Y.
  995. config UCLIBC_HAS_STRING_ARCH_OPT
  996. bool "Use arch-specific assembly string functions (where available)"
  997. default y
  998. help
  999. Answer Y to use any archtecture-specific assembly language string
  1000. functions available for this target plaform.
  1001. Note that assembly implementations are not available for all string
  1002. functions, so some generic (written in C) string functions may
  1003. still be used.
  1004. These are small and fast, the only reason _not_ to say Y here is
  1005. for debugging purposes.
  1006. config UCLIBC_HAS_CTYPE_TABLES
  1007. bool "Use Table Versions Of 'ctype.h' Functions."
  1008. default y
  1009. help
  1010. Answer Y to use table versions of the 'ctype.h' functions.
  1011. While the non-table versions are often smaller when building
  1012. statically linked apps, they work only in stub locale mode.
  1013. Most people will answer Y.
  1014. config UCLIBC_HAS_CTYPE_SIGNED
  1015. bool "Support Signed Characters In 'ctype.h' Functions."
  1016. depends on UCLIBC_HAS_CTYPE_TABLES
  1017. default y
  1018. help
  1019. Answer Y to enable support for passing signed char values to
  1020. the 'ctype.h' functions. ANSI/ISO C99 and SUSv3 specify that
  1021. these functions are only defined for unsigned char values and
  1022. EOF. However, glibc allows negative signed char values as well
  1023. in order to support 'broken old programs'.
  1024. Most people will answer Y.
  1025. choice
  1026. prompt "ctype argument checking"
  1027. depends on UCLIBC_HAS_CTYPE_TABLES
  1028. default UCLIBC_HAS_CTYPE_UNSAFE
  1029. help
  1030. Please select the invalid arg behavior you want for the 'ctype'
  1031. functions.
  1032. The 'ctype' functions are now implemented using table lookups, with
  1033. the arg being the index. This can result in incorrect memory accesses
  1034. or even segfaults for args outside of the allowed range.
  1035. NOTE: This only affects the 'ctype' _functions_. It does not affect
  1036. the macro implementations.
  1037. config UCLIBC_HAS_CTYPE_UNSAFE
  1038. bool "Do not check -- unsafe"
  1039. config UCLIBC_HAS_CTYPE_CHECKED
  1040. bool "Detect and handle appropriately"
  1041. config UCLIBC_HAS_CTYPE_ENFORCED
  1042. bool "Issue a diagnostic and abort()"
  1043. endchoice
  1044. config UCLIBC_HAS_WCHAR
  1045. bool "Wide Character Support"
  1046. default n
  1047. help
  1048. Answer Y to enable wide character support. This will make uClibc
  1049. much larger. It is also currently required for locale support.
  1050. Most people will answer N.
  1051. config UCLIBC_HAS_LOCALE
  1052. bool "Locale Support"
  1053. select UCLIBC_HAS_WCHAR
  1054. select UCLIBC_HAS_CTYPE_TABLES
  1055. default n
  1056. help
  1057. uClibc now has full ANSI/ISO C99 locale support (except for
  1058. wcsftime() and collating items in regex). Be aware that enabling
  1059. this option will make uClibc much larger.
  1060. Enabling UCLIBC_HAS_LOCALE with the default set of supported locales
  1061. (169 UTF-8 locales, and 144 locales for other codesets) will enlarge
  1062. uClibc by around 300k. You can reduce this size by building your own
  1063. custom set of locate data (see extra/locale/LOCALES for details).
  1064. uClibc's locale support is still under development. For example,
  1065. codesets using shift states are not currently supported. Support is
  1066. planned in the next iteration of locale support.
  1067. Answer Y to enable locale support. Most people will answer N.
  1068. choice
  1069. prompt "Locale data"
  1070. depends on UCLIBC_HAS_LOCALE
  1071. default UCLIBC_BUILD_ALL_LOCALE
  1072. config UCLIBC_BUILD_ALL_LOCALE
  1073. bool "All locales"
  1074. depends on UCLIBC_HAS_LOCALE
  1075. help
  1076. This builds all the locales that are available on your
  1077. host-box.
  1078. config UCLIBC_BUILD_MINIMAL_LOCALE
  1079. bool "Only selected locales"
  1080. depends on UCLIBC_HAS_LOCALE
  1081. help
  1082. If you do not need all locales that are available on your
  1083. host-box, then set this to 'Y'.
  1084. config UCLIBC_PREGENERATED_LOCALE_DATA
  1085. bool "Use Pre-generated Locale Data"
  1086. depends on UCLIBC_HAS_LOCALE
  1087. help
  1088. Use pre-built locale data.
  1089. Note that these pregenerated locales are sensitive to your
  1090. target architecture (endianess, bitcount).
  1091. Saying N here is highly recommended.
  1092. endchoice
  1093. config UCLIBC_BUILD_MINIMAL_LOCALES
  1094. string "locales to use"
  1095. depends on UCLIBC_BUILD_MINIMAL_LOCALE
  1096. default "en_US"
  1097. help
  1098. Space separated list of locales to use.
  1099. E.g.:
  1100. en_US en_GB de_AT
  1101. default:
  1102. en_US
  1103. config UCLIBC_DOWNLOAD_PREGENERATED_LOCALE_DATA
  1104. bool "Automagically Download the Pre-generated Locale Data (if necessary)"
  1105. depends on UCLIBC_PREGENERATED_LOCALE_DATA
  1106. default n
  1107. help
  1108. If you would like the build process to use 'wget' to automatically
  1109. download the pregenerated locale data, enable this option. Otherwise
  1110. you will need to obtain the locale data yourself from:
  1111. http://www.uclibc.org/downloads/uClibc-locale-*.tgz
  1112. and place the uClibc-locale-*.tgz tarball in the extra/locale/
  1113. directory.
  1114. Note that the use of pregenerated locale data is discouraged.
  1115. config UCLIBC_HAS_XLOCALE
  1116. bool "Extended Locale Support (experimental/incomplete)"
  1117. depends on UCLIBC_HAS_LOCALE
  1118. default n
  1119. help
  1120. Answer Y to enable extended locale support similar to that provided
  1121. by glibc. This is primarily intended to support libstd++
  1122. functionality.
  1123. However, it also allows thread-specific locale selection via
  1124. uselocale().
  1125. Most people will answer N.
  1126. config UCLIBC_HAS_HEXADECIMAL_FLOATS
  1127. bool "Support hexadecimal float notation"
  1128. depends on UCLIBC_HAS_CTYPE_TABLES
  1129. depends on UCLIBC_HAS_FLOATS
  1130. default n
  1131. help
  1132. Answer Y to enable support for hexadecimal float notation in the
  1133. (wchar and) char string to floating point conversion functions, as
  1134. well as support for the %a and %A conversion specifiers in the
  1135. *printf() and *scanf() functions.
  1136. Most people will answer N.
  1137. config UCLIBC_HAS_GLIBC_DIGIT_GROUPING
  1138. bool "Support glibc's \"'\" flag for allowing locale-specific digit grouping"
  1139. depends on UCLIBC_HAS_LOCALE
  1140. depends on UCLIBC_HAS_FLOATS
  1141. default n
  1142. help
  1143. Answer Y to enable support for glibc's \"'\" flag for allowing
  1144. locale-specific digit grouping in base 10 integer conversions and
  1145. appropriate floating point conversions in the *printf() and *scanf()
  1146. functions.
  1147. Most people will answer N.
  1148. config UCLIBC_HAS_SCANF_LENIENT_DIGIT_GROUPING
  1149. bool "Do not require digit grouping when the \"'\" flag is specified"
  1150. depends on UCLIBC_HAS_GLIBC_DIGIT_GROUPING
  1151. default y
  1152. help
  1153. Answer Y to make digit grouping optional when the \"'\" flag is
  1154. specified.
  1155. This is the standard glibc behavior. If the initial string of digits
  1156. exceeds the maximum group number, the input will be treated as a
  1157. normal non-grouped number.
  1158. Most people will answer N.
  1159. config UCLIBC_HAS_GLIBC_CUSTOM_PRINTF
  1160. bool "Support glibc's register_printf_function() (glibc-compat)"
  1161. depends on !USE_OLD_VFPRINTF
  1162. default n
  1163. help
  1164. Answer Y to support glibc's register_printf_function() to allow an
  1165. application to add its own printf conversion specifiers.
  1166. NOTE: Limits the number or registered specifiers to 10.
  1167. NOTE: Requires new conversion specifiers to be ASCII
  1168. characters (0-0x7f). This is to avoid problems with processing
  1169. format strings in locales with different multibyte conversions.
  1170. Most people will answer N.
  1171. config USE_OLD_VFPRINTF
  1172. bool "Use the old vfprintf implementation"
  1173. depends on !UCLIBC_HAS_WCHAR
  1174. default n
  1175. help
  1176. Set to true to use the old vfprintf instead of the new. This is
  1177. roughly C89 compliant with some extensions, and is much smaller.
  1178. However, it does not support wide chars, positional args, or glibc
  1179. custom printf specifiers.
  1180. Most people will answer N.
  1181. config UCLIBC_PRINTF_SCANF_POSITIONAL_ARGS
  1182. int "Maximum number of positional args. Either 0 or >= 9."
  1183. depends on !USE_OLD_VFPRINTF
  1184. default 9
  1185. help
  1186. Set the maximum number of positional args supported by the
  1187. printf/scanf functions. The Single Unix Specification Version 3
  1188. requires a minimum value of 9. Setting this to a value lower than
  1189. 9 will disable positional arg support and cause the NL_ARGMAX macro
  1190. in limits.h to be #undef'd.
  1191. WARNING! The workspace to support positional args is currently
  1192. allocated on the stack. You probably don't want to set
  1193. this to too high a value.
  1194. Most people will answer 9.
  1195. config UCLIBC_HAS_SCANF_GLIBC_A_FLAG
  1196. bool "Support glibc's 'a' flag for scanf string conversions (not implemented)"
  1197. default n
  1198. help
  1199. NOTE!!! Currently Not Implemented!!! Just A Place Holder!! NOTE!!!
  1200. NOTE!!! Conflicts with an ANSI/ISO C99 scanf flag!! NOTE!!!
  1201. Answer Y to enable support for glibc's 'a' flag for the scanf string
  1202. conversions '%s', '%[', '%ls', '%l[', and '%S'. This is used to
  1203. auto-allocate sufficient memory to hold the data retrieved.
  1204. Most people will answer N.
  1205. choice
  1206. prompt "Stdio buffer size"
  1207. default UCLIBC_HAS_STDIO_BUFSIZ_4096
  1208. help
  1209. Please select a value for BUFSIZ. This will be used by the
  1210. stdio subsystem as the default buffer size for a file, and
  1211. affects fopen(), setvbuf(), etc.
  1212. NOTE: Setting this to 'none' will disable buffering completely.
  1213. However, BUFSIZ will still be defined in stdio.h as 256 because
  1214. many applications use this value.
  1215. config UCLIBC_HAS_STDIO_BUFSIZ_NONE
  1216. bool "none (WARNING - BUFSIZ will be 256 in stdio.h)"
  1217. depends on !UCLIBC_HAS_WCHAR
  1218. config UCLIBC_HAS_STDIO_BUFSIZ_256
  1219. bool "256 (minimum ANSI/ISO C99 value)"
  1220. config UCLIBC_HAS_STDIO_BUFSIZ_512
  1221. bool "512"
  1222. config UCLIBC_HAS_STDIO_BUFSIZ_1024
  1223. bool "1024"
  1224. config UCLIBC_HAS_STDIO_BUFSIZ_2048
  1225. bool "2048"
  1226. config UCLIBC_HAS_STDIO_BUFSIZ_4096
  1227. bool "4096"
  1228. config UCLIBC_HAS_STDIO_BUFSIZ_8192
  1229. bool "8192"
  1230. # If you add more choices, you will need to update uClibc_stdio.h.
  1231. endchoice
  1232. choice
  1233. prompt "Stdio builtin buffer size (uClibc-specific)"
  1234. depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
  1235. default UCLIBC_HAS_STDIO_BUILTIN_BUFFER_NONE
  1236. help
  1237. When a FILE is created with fopen(), an attempt is made to allocate
  1238. a BUFSIZ buffer for it. If the allocation fails, fopen() will still
  1239. succeed but the FILE will be unbuffered.
  1240. This option adds a small amount of space to each FILE to act as an
  1241. emergency buffer in the event of a buffer allocation failure.
  1242. Most people will answer None.
  1243. config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_NONE
  1244. bool "None"
  1245. config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_4
  1246. bool "4"
  1247. config UCLIBC_HAS_STDIO_BUILTIN_BUFFER_8
  1248. bool "8"
  1249. # If you add more choices, you will need to update uClibc_stdio.h.
  1250. endchoice
  1251. config UCLIBC_HAS_STDIO_SHUTDOWN_ON_ABORT
  1252. bool "Attempt to shutdown stdio subsystem when abort() is called."
  1253. default n
  1254. help
  1255. ANSI/ISO C99 requires abort() to be asyn-signal-safe. So there was
  1256. a behavioral change made in SUSv3. Previously, abort() was required
  1257. to have the affect of fclose() on all open streams. The wording has
  1258. been changed to "may" from "shall".
  1259. Most people will answer N.
  1260. config UCLIBC_HAS_STDIO_GETC_MACRO
  1261. bool "Provide a macro version of getc()"
  1262. depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
  1263. default y
  1264. help
  1265. Provide a macro version of getc().
  1266. Most people will answer Y.
  1267. config UCLIBC_HAS_STDIO_PUTC_MACRO
  1268. bool "Provide a macro version of putc()"
  1269. depends on !UCLIBC_HAS_STDIO_BUFSIZ_NONE
  1270. default y
  1271. help
  1272. Provide a macro version of putc().
  1273. Most people will answer Y.
  1274. config UCLIBC_HAS_STDIO_AUTO_RW_TRANSITION
  1275. bool "Support auto-r/w transition"
  1276. default y
  1277. help
  1278. Answer Y to enable the stdio subsystem to automaticly transition
  1279. between reading and writing. This relaxes the ANSI/ISO C99
  1280. requirement:
  1281. When a file is opened with update mode ('+' as the second or third
  1282. character in the list of mode argument values), both input and output
  1283. may be performed on the associated stream. However, output shall not
  1284. be directly followed by input without an intervening call to the
  1285. fflush function or to a file positioning function (fseek, fsetpos,
  1286. or rewind), and input shall not be directly followed by output without
  1287. an intervening call to a file positioning function, unless the input
  1288. operation encounters end­of­file.
  1289. Most people will answer Y.
  1290. config UCLIBC_HAS_FOPEN_LARGEFILE_MODE
  1291. bool "Support an fopen() 'F' flag for large file mode (uClibc-specific)"
  1292. depends on UCLIBC_HAS_LFS
  1293. default n
  1294. help
  1295. Answer Y to enable a uClibc-specific extension to allow passing an
  1296. additional 'F' flag in the mode string for fopen() to specify that
  1297. the file should be open()ed with the O_LARGEFILE flag set.
  1298. Most people will answer N.
  1299. config UCLIBC_HAS_FOPEN_EXCLUSIVE_MODE
  1300. bool "Support an fopen() 'x' flag for exclusive mode (glibc-compat)"
  1301. default n
  1302. help
  1303. Answer Y to support a glibc extension to allow passing
  1304. additional 'x' flag in the mode string for fopen() to specify that
  1305. the file should be open()ed with the O_EXCL flag set.
  1306. Most people will answer N.
  1307. config UCLIBC_HAS_GLIBC_CUSTOM_STREAMS
  1308. bool "Support fmemopen(), open_memstream(), and fopencookie() (glibc-compat)"
  1309. default n
  1310. help
  1311. Answer Y to support the glibc 'custom stream' extension functions
  1312. fmemopen(), open_memstream(), and fopencookie().
  1313. NOTE: There are some minor differences regarding seeking behavior.
  1314. Most people will answer N.
  1315. config UCLIBC_HAS_PRINTF_M_SPEC
  1316. bool "Support the '%m' specifier in printf format strings (glibc-compat)"
  1317. default n
  1318. help
  1319. Answer Y to support a glibc extension to interpret '%m' in printf
  1320. format strings as an instruction to output the error message string
  1321. (as generated by strerror) corresponding to the current value of
  1322. 'errno'.
  1323. Most people will answer N.
  1324. config UCLIBC_HAS_ERRNO_MESSAGES
  1325. bool "Include the errno message text in the library"
  1326. default y
  1327. help
  1328. Answer Y if you want to include the errno message text in the
  1329. library. This adds about 3K to the library, but enables strerror()
  1330. to generate text other than 'Unknown error <number>'.
  1331. Most people will answer Y.
  1332. config UCLIBC_HAS_SYS_ERRLIST
  1333. bool "Support sys_errlist[] (obsolete-compat)"
  1334. depends on UCLIBC_HAS_ERRNO_MESSAGES
  1335. default n
  1336. help
  1337. Answer Y if you want to support the obsolete sys_errlist[].
  1338. This adds about 0.5k to the library, except for the mips
  1339. arch where it adds over 4K.
  1340. WARNING! In the future, support for sys_errlist[] may be unavailable
  1341. in at least some configurations. In fact, it may be removed
  1342. altogether.
  1343. Most people will answer N.
  1344. Application writers: use the strerror(3) function.
  1345. config UCLIBC_HAS_SIGNUM_MESSAGES
  1346. bool "Include the signum message text in the library"
  1347. default y
  1348. help
  1349. Answer Y if you want to include the signum message text in the
  1350. library. This adds about 0.5K to the library, but enables strsignal()
  1351. to generate text other than 'Unknown signal <number>'.
  1352. Most people will answer Y.
  1353. config UCLIBC_HAS_SYS_SIGLIST
  1354. bool "Support sys_siglist[] (bsd-compat)"
  1355. depends on UCLIBC_HAS_SIGNUM_MESSAGES
  1356. default n
  1357. help
  1358. Answer Y if you want to support sys_siglist[].
  1359. WARNING! In the future, support for sys_siglist[] may be unavailable
  1360. in at least some configurations. In fact, it may be removed
  1361. altogether.
  1362. Most people will answer N.
  1363. config UCLIBC_HAS_GETTEXT_AWARENESS
  1364. bool "Include gettext awareness"
  1365. depends on UCLIBC_HAS_LOCALE && UCLIBC_MJN3_ONLY
  1366. default n
  1367. help
  1368. NOTE!!! Not yet integrated with strerror and strsignal. NOTE!!!
  1369. Answer Y if you want to include weak stub gettext support and
  1370. make the *strerror*() and strsignal() functions gettext-aware.
  1371. Currently, to get functional gettext functionality you will need
  1372. to use gnu gettext.
  1373. Most people will answer N.
  1374. config UCLIBC_HAS_GNU_GETOPT
  1375. bool "Support gnu getopt"
  1376. default y
  1377. help
  1378. Answer Y if you want to include full gnu getopt() instead of a
  1379. (much smaller) SUSv3 compatible getopt().
  1380. Most people will answer Y.
  1381. config UCLIBC_HAS_STDIO_FUTEXES
  1382. bool "Use futexes for multithreaded I/O locking"
  1383. default n
  1384. depends on UCLIBC_HAS_THREADS_NATIVE
  1385. help
  1386. If you want to compile uClibc to use futexes for low-level
  1387. I/O locking, answer Y. Otherwise, answer N.
  1388. config UCLIBC_HAS_GETOPT_LONG
  1389. bool "Support getopt_long/getopt_long_only"
  1390. depends on !UCLIBC_HAS_GNU_GETOPT
  1391. default y
  1392. help
  1393. Answer Y if you want to include getopt_long[_only() used by many
  1394. apps, even busybox.
  1395. Most people will answer Y.
  1396. config UCLIBC_HAS_GNU_GETSUBOPT
  1397. bool "Support glibc getsubopt"
  1398. default y
  1399. help
  1400. Answer Y if you want to include glibc getsubopt() instead of a
  1401. smaller SUSv3 compatible getsubopt().
  1402. Most people will answer Y.
  1403. endmenu
  1404. menu "Big and Tall"
  1405. config UCLIBC_HAS_REGEX
  1406. bool "Regular Expression Support"
  1407. default y
  1408. help
  1409. POSIX regular expression code is really big -- 53k all by itself.
  1410. If you don't use regular expressions, turn this off and save space.
  1411. Of course, if you only statically link, leave this on, since it will
  1412. only be included in your apps if you use regular expressions.
  1413. config UCLIBC_HAS_REGEX_OLD
  1414. bool "Use the older (stable) regular expression code"
  1415. depends on UCLIBC_HAS_REGEX
  1416. default y
  1417. help
  1418. There are two versions of regex. The older (stable) version has
  1419. been in uClibc for quite a long time but hasn't seen too many
  1420. updates. It also has some known issues when dealing with uncommon
  1421. corner cases and multibyte/unicode strings. However, it is quite
  1422. a bit smaller than the newer version.
  1423. If the older version has worked for you and you don't need unicode
  1424. support, then stick with the old version (and say Y here).
  1425. Otherwise, you should use the new version (and say N here).
  1426. config UCLIBC_HAS_FNMATCH
  1427. bool "fnmatch Support"
  1428. default y
  1429. help
  1430. POSIX fnmatch.
  1431. config UCLIBC_HAS_FNMATCH_OLD
  1432. bool "Use the older (stable) fnmatch code"
  1433. depends on UCLIBC_HAS_FNMATCH
  1434. default y
  1435. help
  1436. There are two versions of fnmatch. The older (stable) version has
  1437. been in uClibc for quite a long time but hasn't seen too many
  1438. updates. It also has some known issues when dealing with uncommon
  1439. corner cases and multibyte/unicode strings. However, it is quite
  1440. a bit smaller than the newer version.
  1441. If the older version has worked for you and you don't need unicode
  1442. support, then stick with the old version (and say Y here).
  1443. Otherwise, you should use the new version (and say N here).
  1444. config UCLIBC_HAS_WORDEXP
  1445. bool "Support the wordexp() interface"
  1446. depends on UCLIBC_HAS_GLOB
  1447. default n
  1448. help
  1449. The SuSv3 wordexp() interface performs word expansions per the Shell
  1450. and Utilities volume of IEEE Std 1003.1-2001, Section 2.6. It is
  1451. intended for use by applications that want to implement all of the
  1452. standard Bourne shell expansions on input data.
  1453. This interface is rarely used, and very large. Unless you have a
  1454. pressing need for wordexp(), you should probably answer N.
  1455. config UCLIBC_HAS_NFTW
  1456. bool "Support the nftw() interface"
  1457. default n
  1458. help
  1459. The SuSv3 nftw() interface is used to recursively descend
  1460. directory paths while repeatedly calling a function.
  1461. This interface is rarely used, and adds around 4.5k. Unless you have
  1462. a pressing need for nftw(), you should probably answer N.
  1463. config UCLIBC_HAS_FTW
  1464. bool "Support the ftw() interface"
  1465. default n
  1466. depends on UCLIBC_SUSV4_LEGACY
  1467. help
  1468. The SuSv3 ftw() interface is used to recursively descend
  1469. directory paths while repeatedly calling a function.
  1470. This interface is rarely used, and adds around 4.5k. Unless you have
  1471. a pressing need for ftw(), you should probably answer N.
  1472. config UCLIBC_HAS_GLOB
  1473. bool "Support the glob() interface"
  1474. depends on UCLIBC_HAS_FNMATCH
  1475. default y
  1476. help
  1477. The glob interface is somewhat large (weighing in at about 2,5k). It
  1478. is used fairly often, but is an option since people wanting to go for
  1479. absolute minimum size may wish to omit it.
  1480. Most people will answer Y.
  1481. config UCLIBC_HAS_GNU_GLOB
  1482. bool "Support gnu glob() interface"
  1483. depends on UCLIBC_HAS_GLOB
  1484. default n
  1485. help
  1486. The gnu glob interface is somewhat larger (weighing in at about 4,2k)
  1487. than it's SuSv3 counterpart (and is out of date). It is an old copy
  1488. from glibc and does not support all the GNU specific options.
  1489. Answer Y if you want to include full gnu glob() instead of the smaller
  1490. SUSv3 compatible glob().
  1491. Most people will answer N.
  1492. endmenu
  1493. menu "Library Installation Options"
  1494. config SHARED_LIB_LOADER_PREFIX
  1495. string "Shared library loader path"
  1496. depends on HAVE_SHARED
  1497. default "$(RUNTIME_PREFIX)lib"
  1498. help
  1499. When using shared libraries, this path is the location where the
  1500. shared library will be invoked. This value will be compiled into
  1501. every binary compiled with uClibc.
  1502. For a typical target system this should be set to "/lib", such that
  1503. 'make install' will install /lib/ld-uClibc.so.0.
  1504. BIG FAT WARNING:
  1505. If you do not have a shared library loader with the correct name
  1506. sitting in the directory this points to, your binaries will not
  1507. run.
  1508. config RUNTIME_PREFIX
  1509. string "uClibc runtime library directory"
  1510. default "/usr/$(TARGET_ARCH)-linux-uclibc/"
  1511. help
  1512. RUNTIME_PREFIX is the directory into which the uClibc runtime
  1513. libraries will be installed. The result will look something
  1514. like the following:
  1515. $(RUNTIME_PREFIX)/
  1516. lib/ <contains all runtime libraries>
  1517. usr/bin/ldd <the ldd utility program>
  1518. sbin/ldconfig <the ldconfig utility program>
  1519. This value is used by the 'make install' Makefile target. Since this
  1520. directory is compiled into the shared library loader, you will need to
  1521. recompile uClibc if you change this value...
  1522. For a typical target system this should be set to "/", such that
  1523. 'make install' will install /lib/libuClibc-<VERSION>.so
  1524. config DEVEL_PREFIX
  1525. string "uClibc development environment directory"
  1526. default "/usr/$(TARGET_ARCH)-linux-uclibc/usr/"
  1527. help
  1528. DEVEL_PREFIX is the directory into which the uClibc development
  1529. environment will be installed. The result will look something
  1530. like the following:
  1531. $(DEVEL_PREFIX)/
  1532. lib/ <contains static libs>
  1533. include/ <Where all the header files go>
  1534. This value is used by the 'make install' Makefile target when
  1535. installing a uClibc development environment.
  1536. For a typical target system this should be set to "/usr", such that
  1537. 'make install' will install /usr/include/<header files>.
  1538. config HARDWIRED_ABSPATH
  1539. bool "Hardwire absolute paths into linker scripts"
  1540. default y
  1541. help
  1542. This prepends absolute paths to the libraries mentioned in linker
  1543. scripts such as libc.so.
  1544. This is a build time optimization. It has no impact on dynamic
  1545. linking at runtime, which doesn't use linker scripts.
  1546. You must disable this to use uClibc with a relocatable toolchain,
  1547. such as the prebuilt binary cross compilers at
  1548. http://uclibc.org/downloads/binaries which may be installed at an
  1549. arbitrary location (such as in a user's home directory).
  1550. The amount of time saved by this optimization is actually too small to
  1551. measure. The linker just had to search the library path to find the
  1552. linker script, so the dentries are cache hot if it has to search the
  1553. same path again. But it's what glibc does, so we do it too.
  1554. endmenu
  1555. menu "Security options"
  1556. config UCLIBC_BUILD_PIE
  1557. bool "Build utilities as ET_DYN/PIE executables"
  1558. depends on HAVE_SHARED
  1559. depends on TARGET_arm || TARGET_frv || TARGET_i386 || TARGET_mips || TARGET_powerpc
  1560. select FORCE_SHAREABLE_TEXT_SEGMENTS
  1561. default n
  1562. help
  1563. If you answer Y here, ldd and iconv are built as ET_DYN/PIE
  1564. executables.
  1565. It requires gcc-3.4 and binutils-2.15 (for arm 2.16) or later.
  1566. More about ET_DYN/PIE binaries on <http://pax.grsecurity.net/> .
  1567. WARNING: This option also enables FORCE_SHAREABLE_TEXT_SEGMENTS, so
  1568. all libraries have to be built with -fPIC or -fpic, and all
  1569. assembler functions must be written as position independent
  1570. code (PIC).
  1571. config UCLIBC_HAS_ARC4RANDOM
  1572. bool "Include the arc4random() function"
  1573. default n
  1574. help
  1575. Answer Y to support the OpenBSD-like arc4random() function. This
  1576. function picks a random number between 0 and N, and will always return
  1577. something even if the random driver is dead. If urandom fails then
  1578. gettimeofday(2) will be used as the random seed. This function is
  1579. designed to be more dependable than invoking /dev/urandom directly.
  1580. OpenSSL and OpenNTPD currently support this function.
  1581. Most people will answer N.
  1582. config HAVE_NO_SSP
  1583. bool
  1584. default n
  1585. config UCLIBC_HAS_SSP
  1586. bool "Support for GCC stack smashing protector"
  1587. depends on !HAVE_NO_SSP
  1588. default n
  1589. help
  1590. Add code to support GCC's -fstack-protector[-all] option to uClibc.
  1591. This requires GCC 4.1 or newer. GCC does not have to provide libssp,
  1592. the needed functions are added to ldso/libc instead.
  1593. GCC's stack protector is a reimplementation of IBM's propolice.
  1594. See http://www.trl.ibm.com/projects/security/ssp/ and
  1595. http://www.linuxfromscratch.org/hints/downloads/files/ssp.txt
  1596. for details.
  1597. Note that NOEXECSTACK on a kernel with address space randomization
  1598. is generally sufficient to prevent most buffer overflow exploits
  1599. without increasing code size. This option essentially adds debugging
  1600. code to catch them.
  1601. Most people will answer N.
  1602. config UCLIBC_HAS_SSP_COMPAT
  1603. bool "Support for gcc-3.x propolice smashing stack protector"
  1604. depends on UCLIBC_HAS_SSP
  1605. default n
  1606. help
  1607. Add gcc-3.x propolice smashing stack protector to the library.
  1608. This requires a patched version of GCC, supporting the
  1609. -fstack-protector[-all] options, with the __guard and
  1610. __stack_smash_handler functions removed from libgcc.
  1611. These functions are added to ldso/libc instead.
  1612. More information at:
  1613. <http://www.research.ibm.com/trl/projects/security/ssp/>
  1614. Most people will answer N.
  1615. config SSP_QUICK_CANARY
  1616. bool "Use simple guard values without accessing /dev/urandom"
  1617. depends on UCLIBC_HAS_SSP
  1618. default n
  1619. help
  1620. Use gettimeofday(2) to define the __guard without accessing
  1621. /dev/urandom.
  1622. WARNING: This makes smashing stack protector vulnerable to timing
  1623. attacks.
  1624. Most people will answer N.
  1625. choice
  1626. prompt "Propolice protection blocking signal"
  1627. depends on UCLIBC_HAS_SSP
  1628. default PROPOLICE_BLOCK_ABRT if ! DODEBUG
  1629. default PROPOLICE_BLOCK_SEGV if DODEBUG
  1630. help
  1631. "abort" use SIGABRT to block offending programs.
  1632. This is the default implementation.
  1633. "segfault" use SIGSEGV to block offending programs.
  1634. Use this for debugging.
  1635. If unsure, answer "abort".
  1636. config PROPOLICE_BLOCK_ABRT
  1637. bool "abort"
  1638. config PROPOLICE_BLOCK_SEGV
  1639. bool "segfault"
  1640. endchoice
  1641. config UCLIBC_BUILD_SSP
  1642. bool "Build uClibc with -fstack-protector"
  1643. depends on UCLIBC_HAS_SSP
  1644. default n
  1645. help
  1646. Build all uClibc libraries and executables with -fstack-protector,
  1647. adding extra stack overflow checking to most uClibc functions.
  1648. config UCLIBC_BUILD_RELRO
  1649. bool "Build uClibc with linker option -z RELRO"
  1650. depends on HAVE_SHARED
  1651. default y
  1652. help
  1653. Build all libraries and executables with "ld -z relro".
  1654. This tells the linker to mark chunks of an executable or shared
  1655. library read-only after applying dynamic relocations. (This comes
  1656. up when a global const variable is initialized to the address of a
  1657. function or the value of another global variable.)
  1658. This is a fairly obscure option the ld man page doesn't even bother
  1659. to document properly. It's a security paranoia issue that's more
  1660. likely to consume memory (by allocating an extra page) rather than
  1661. save it.
  1662. This is explained in more depth at
  1663. http://www.airs.com/blog/archives/189
  1664. Nobody is likely to care whether you say Y or N here.
  1665. config UCLIBC_BUILD_NOW
  1666. bool "Build uClibc with linker option -z NOW"
  1667. depends on HAVE_SHARED
  1668. default n
  1669. help
  1670. Build all libraries and executables with "ld -z now".
  1671. This tells the linker to resolve all symbols when the library is
  1672. first loaded, rather than when each function is first called. This
  1673. increases start-up latency by a few microseconds and may do
  1674. unnecessary work (resolving symbols that are never used), but the
  1675. realtime people like it for making microbenchmark timings slightly
  1676. more predictable and in some cases it can be slightly faster due to
  1677. CPU cache behavior (not having to fault the linker back in to do
  1678. lazy symbol resolution).
  1679. Most people can't tell the difference between selecting Y or N here.
  1680. config UCLIBC_BUILD_NOEXECSTACK
  1681. bool "Build uClibc with noexecstack marking"
  1682. default y
  1683. help
  1684. Mark all assembler files as noexecstack, which will mark uClibc
  1685. as not requiring an executable stack. (This doesn't prevent other
  1686. files you link against from claiming to need an executable stack, it
  1687. just won't cause uClibc to request it unnecessarily.)
  1688. This is a security thing to make buffer overflows harder to exploit.
  1689. By itself, it's kind of useless, as Linus Torvalds explained in 1998:
  1690. http://old.lwn.net/1998/0806/a/linus-noexec.html
  1691. It only actually provides any security when combined with address
  1692. space randomization, explained here: http://lwn.net/Articles/121845/
  1693. Address space randomization is on by default in current linux
  1694. kernels (although it can be disabled using the option
  1695. CONFIG_COMPAT_BRK).
  1696. You should probably say Y.
  1697. endmenu
  1698. menu "uClibc development/debugging options"
  1699. config CROSS_COMPILER_PREFIX
  1700. string "Cross-compiling toolchain prefix"
  1701. default ""
  1702. help
  1703. The prefix used to execute your cross-compiling toolchain. For
  1704. example, if you run 'arm-linux-uclibc-gcc' to compile something,
  1705. then enter 'arm-linux-uclibc-' here.
  1706. config UCLIBC_EXTRA_CFLAGS
  1707. string "Enter any extra CFLAGS to use to build uClibc"
  1708. default ""
  1709. help
  1710. Add any additional CFLAGS to be used to build uClibc.
  1711. config DODEBUG
  1712. bool "Build uClibc with debugging symbols"
  1713. default n
  1714. select EXTRA_WARNINGS
  1715. help
  1716. Say Y here if you wish to compile uClibc with debugging symbols.
  1717. This will allow you to use a debugger to examine uClibc internals
  1718. while applications are running. This increases the size of the
  1719. library considerably and should only be used when doing development.
  1720. If you are doing development and want to debug uClibc, answer Y.
  1721. Otherwise, answer N.
  1722. config DODEBUG_PT
  1723. bool "Build pthread with debugging output"
  1724. depends on UCLIBC_HAS_THREADS && LINUXTHREADS_OLD
  1725. default n
  1726. help
  1727. Enable debug output in libpthread. This is only useful when doing
  1728. development in libpthread itself.
  1729. Otherwise, answer N.
  1730. config DOSTRIP
  1731. bool "Strip libraries and executables"
  1732. default y
  1733. depends on !DODEBUG
  1734. help
  1735. Say Y here if you do wish to strip all uClibc libraries and
  1736. executables. No stripping increases the size of the binaries
  1737. considerably, but makes it possible to debug uClibc libraries.
  1738. Most people will answer Y.
  1739. config DOASSERTS
  1740. bool "Build uClibc with run-time assertion testing"
  1741. default n
  1742. help
  1743. Say Y here to include runtime assertion tests.
  1744. This enables runtime assertion testing in some code, which can
  1745. increase the size of the library and incur runtime overhead.
  1746. If you say N, then this testing will be disabled.
  1747. config SUPPORT_LD_DEBUG
  1748. bool "Build the shared library loader with debugging support"
  1749. depends on HAVE_SHARED
  1750. default n
  1751. help
  1752. Answer Y here to enable all the extra code needed to debug the uClibc
  1753. native shared library loader. The level of debugging noise that is
  1754. generated depends on the LD_DEBUG environment variable... Just set
  1755. LD_DEBUG to something like: 'LD_DEBUG=token1,token2,.. prog' to
  1756. debug your application. Diagnostic messages will then be printed to
  1757. the stderr.
  1758. For now these debugging tokens are available:
  1759. detail provide more information for some options
  1760. move display copy processing
  1761. symbols display symbol table processing
  1762. reloc display relocation processing; detail shows the
  1763. relocation patch
  1764. nofixups never fixes up jump relocations
  1765. bindings displays the resolve processing (function calls);
  1766. detail shows the relocation patch
  1767. all Enable everything!
  1768. The additional environment variable:
  1769. LD_DEBUG_OUTPUT=file
  1770. redirects the diagnostics to an output file created using
  1771. the specified name and the process id as a suffix.
  1772. An excellent start is simply:
  1773. $ LD_DEBUG=binding,move,symbols,reloc,detail ./appname
  1774. or to log everything to a file named 'logfile', try this
  1775. $ LD_DEBUG=all LD_DEBUG_OUTPUT=logfile ./appname
  1776. If you are doing development and want to debug uClibc's shared library
  1777. loader, answer Y. Mere mortals answer N.
  1778. config SUPPORT_LD_DEBUG_EARLY
  1779. bool "Build the shared library loader with early debugging support"
  1780. depends on HAVE_SHARED
  1781. default n
  1782. help
  1783. Answer Y here to if you find the uClibc shared library loader is
  1784. crashing or otherwise not working very early on. This is typical
  1785. only when starting a new port when you haven't figured out how to
  1786. properly get the values for argc, argv, environ, etc. This method
  1787. allows a degree of visibility into the very early shared library
  1788. loader initialization process. If you are doing development and want
  1789. to debug the uClibc shared library loader early initialization,
  1790. answer Y. Mere mortals answer N.
  1791. config UCLIBC_MALLOC_DEBUGGING
  1792. bool "Build malloc with debugging support"
  1793. depends on MALLOC || MALLOC_STANDARD
  1794. default n
  1795. help
  1796. Answer Y here to compile extra debugging support code into malloc.
  1797. Malloc debugging output may then be enabled at runtime using the
  1798. MALLOC_DEBUG environment variable.
  1799. The value of MALLOC_DEBUG should be an integer, which is interpreted
  1800. as a bitmask with the following bits:
  1801. 1 - do extra consistency checking
  1802. 2 - output messages for malloc/free calls and OS
  1803. allocation calls
  1804. 4 - output messages for the `MMB' layer
  1805. 8 - output messages for internal malloc heap manipulation
  1806. calls
  1807. Because this increases the size of malloc appreciably (due to strings
  1808. etc), you should say N unless you need to debug a malloc problem.
  1809. config WARNINGS
  1810. string "Compiler Warnings"
  1811. default "-Wall"
  1812. help
  1813. Set this to the set of gcc warnings you wish to see while compiling.
  1814. config EXTRA_WARNINGS
  1815. bool "Enable extra annoying warnings"
  1816. default n
  1817. help
  1818. If you wish to build with extra warnings enabled, say Y here.
  1819. config DOMULTI
  1820. bool "Compile all sources at once into an object"
  1821. default n
  1822. help
  1823. Set this to compile all sources at once into an object (IMA).
  1824. This mode of compilation uses alot of memory but may produce
  1825. smaller binaries.
  1826. Note that you need a very recent GCC for this to work, like
  1827. gcc >= 4.3 plus eventually some patches.
  1828. If unsure, keep the default of N.
  1829. config UCLIBC_MJN3_ONLY
  1830. bool "Manuel's hidden warnings"
  1831. default n
  1832. help
  1833. Answer Y here to see all Manuel's personal notes, warnings, and todos.
  1834. Most people will answer N.
  1835. endmenu