3 mainmenu "Buildroot $BR2_VERSION Configuration"
5 config BR2_HAVE_DOT_CONFIG
11 option env="BR2_VERSION_FULL"
19 option env="BR2_EXTERNAL"
23 option env="BUILD_DIR"
25 # Hidden config symbols for packages to check system gcc version
26 config BR2_HOST_GCC_VERSION
28 option env="HOST_GCC_VERSION"
30 config BR2_HOST_GCC_AT_LEAST_4_6
32 default y if BR2_HOST_GCC_VERSION = "4 6"
34 config BR2_HOST_GCC_AT_LEAST_4_7
36 default y if BR2_HOST_GCC_VERSION = "4 7"
37 select BR2_HOST_GCC_AT_LEAST_4_6
39 config BR2_HOST_GCC_AT_LEAST_4_8
41 default y if BR2_HOST_GCC_VERSION = "4 8"
42 select BR2_HOST_GCC_AT_LEAST_4_7
44 config BR2_HOST_GCC_AT_LEAST_4_9
46 default y if BR2_HOST_GCC_VERSION = "4 9"
47 select BR2_HOST_GCC_AT_LEAST_4_8
49 config BR2_HOST_GCC_AT_LEAST_5
51 default y if BR2_HOST_GCC_VERSION = "5"
52 select BR2_HOST_GCC_AT_LEAST_4_9
54 config BR2_HOST_GCC_AT_LEAST_6
56 default y if BR2_HOST_GCC_VERSION = "6"
57 select BR2_HOST_GCC_AT_LEAST_5
59 # Hidden boolean selected by packages in need of Java in order to build
61 config BR2_NEEDS_HOST_JAVA
64 # Hidden boolean selected by packages in need of javac in order to build
65 # (example: classpath)
66 config BR2_NEEDS_HOST_JAVAC
69 # Hidden boolean selected by packages in need of jar in order to build
70 # (example: classpath)
71 config BR2_NEEDS_HOST_JAR
74 # Hidden boolean selected by pre-built packages for x86, when they
75 # need to run on x86-64 machines (example: pre-built external
76 # toolchains, binary tools like SAM-BA, etc.).
77 config BR2_HOSTARCH_NEEDS_IA32_LIBS
80 # Hidden boolean selected by packages that need to build 32 bits
81 # binaries with the host compiler, even on 64 bits build machines (e.g
83 config BR2_HOSTARCH_NEEDS_IA32_COMPILER
86 source "arch/Config.in"
94 default "wget --passive-ftp -nd -t 3"
97 string "Subversion (svn) command"
101 string "Bazaar (bzr) command"
112 config BR2_LOCALFILES
113 string "Local files retrieval command"
117 string "Secure copy (scp) command"
121 string "Secure shell (ssh) command"
125 string "Mercurial (hg) command"
129 string "zcat command"
132 Command to be used to extract a gzip'ed file to stdout. zcat
133 is identical to gunzip -c except that the former may not be
134 available on your system.
135 Default is "gzip -d -c"
136 Other possible values include "gunzip -c" or "zcat".
139 string "bzcat command"
142 Command to be used to extract a bzip2'ed file to stdout.
143 bzcat is identical to bunzip2 -c except that the former may
144 not be available on your system.
146 Other possible values include "bunzip2 -c" or "bzip2 -d -c".
149 string "xzcat command"
152 Command to be used to extract a xz'ed file to stdout.
155 config BR2_TAR_OPTIONS
159 Options to pass to tar when extracting the sources.
160 E.g. " -v --exclude='*.svn*'" to exclude all .svn internal files
165 config BR2_DEFCONFIG_FROM_ENV
167 option env="BR2_DEFCONFIG"
170 string "Location to save buildroot config"
171 default BR2_DEFCONFIG_FROM_ENV if BR2_DEFCONFIG_FROM_ENV != ""
172 default "$(CONFIG_DIR)/defconfig"
174 When running 'make savedefconfig', the defconfig file will be
175 saved in this location.
178 string "Download dir"
179 default "$(TOPDIR)/dl"
181 Directory to store all the source files that we need to fetch.
182 If the Linux shell environment has defined the BR2_DL_DIR
183 environment variable, then this overrides this configuration
186 The default is $(TOPDIR)/dl
190 default "$(BASE_DIR)/host"
192 Directory to store all the binary files that are built for the
193 host. This includes the cross compilation toolchain when
194 building the internal buildroot toolchain.
196 The default is $(BASE_DIR)/host
198 menu "Mirrors and Download locations"
200 config BR2_PRIMARY_SITE
201 string "Primary download site"
204 Primary site to download from. If this option is set then
205 buildroot will try to download package source first from this
206 site and try the default if the file is not found.
208 - URIs recognized by $(WGET)
209 - local URIs of the form file://absolutepath
210 - scp URIs of the form scp://[user@]host:path.
212 config BR2_PRIMARY_SITE_ONLY
213 bool "Only allow downloads from primary download site"
214 depends on BR2_PRIMARY_SITE != ""
216 If this option is enabled, downloads will only be attempted
217 from the primary download site. Other locations, like the
218 package's official download location or the backup download
219 site, will not be considered. Therefore, if the package is not
220 present on the primary site, the download fails.
222 This is useful for project developers who want to ensure that
223 the project can be built even if the upstream tarball
226 if !BR2_PRIMARY_SITE_ONLY
228 config BR2_BACKUP_SITE
229 string "Backup download site"
230 default "http://sources.buildroot.net"
232 Backup site to download from. If this option is set then
233 buildroot will fall back to download package sources from here
234 if the normal location fails.
236 config BR2_KERNEL_MIRROR
237 string "Kernel.org mirror"
238 default "https://cdn.kernel.org/pub"
240 kernel.org is mirrored on a number of servers around the
241 world. The following allows you to select your preferred
242 mirror. By default, a CDN is used, which automatically
243 redirects to a mirror geographically close to you.
245 Have a look on the kernel.org site for a list of mirrors, then
246 enter the URL to the base directory. Examples:
248 http://www.XX.kernel.org/pub (XX = country code)
249 http://mirror.aarnet.edu.au/pub/ftp.kernel.org
251 config BR2_GNU_MIRROR
252 string "GNU Software mirror"
253 default "http://ftpmirror.gnu.org"
255 GNU has multiple software mirrors scattered around the
256 world. The following allows you to select your preferred
257 mirror. By default, a generic address is used, which
258 automatically selects an up-to-date and local mirror.
260 Have a look on the gnu.org site for a list of mirrors, then
261 enter the URL to the base directory. Examples:
263 http://ftp.gnu.org/pub/gnu
264 http://mirror.aarnet.edu.au/pub/gnu
266 config BR2_LUAROCKS_MIRROR
267 string "LuaRocks mirror"
268 default "http://rocks.moonscript.org"
272 See http://luarocks.org
274 config BR2_CPAN_MIRROR
275 string "CPAN mirror (Perl packages)"
276 default "http://cpan.metacpan.org"
278 CPAN (Comprehensive Perl Archive Network) is a repository of
279 Perl packages. It has multiple software mirrors scattered
280 around the world. This option allows you to select a mirror.
282 The list of mirrors is available at:
283 http://search.cpan.org/mirror
290 int "Number of jobs to run simultaneously (0 for auto)"
293 Number of jobs to run simultaneously. If 0, determine
294 automatically according to number of CPUs on the host system.
297 bool "Enable compiler cache"
299 This option will enable the use of ccache, a compiler cache.
300 It will cache the result of previous builds to speed up future
301 builds. By default, the cache is stored in
302 $HOME/.buildroot-ccache.
304 Note that Buildroot does not try to invalidate the cache
305 contents when the compiler changes in an incompatible way.
306 Therefore, if you make a change to the compiler version and/or
307 configuration, you are responsible for purging the ccache
308 cache by removing the $HOME/.buildroot-ccache directory.
312 config BR2_CCACHE_DIR
313 string "Compiler cache location"
314 default "$(HOME)/.buildroot-ccache"
316 Where ccache should store cached files.
318 config BR2_CCACHE_INITIAL_SETUP
319 string "Compiler cache initial setup"
321 Initial ccache settings to apply, such as --max-files or
324 For example, if your project is known to require more space
325 than the default max cache size, then you might want to
326 increase the cache size to a suitable amount using the -M
329 The string you specify here is passed verbatim to ccache.
330 Refer to ccache documentation for more details.
332 These initial settings are applied after ccache has been
335 config BR2_CCACHE_USE_BASEDIR
336 bool "Use relative paths"
339 Allow ccache to convert absolute paths within the output
340 directory into relative paths.
342 During the build, many -I include directives are given with an
343 absolute path. These absolute paths end up in the hashes that
344 are computed by ccache. Therefore, when you build from a
345 different directory, the hash will be different and the cached
346 object will not be used.
348 To improve cache performance, set this option to y. This
349 allows ccache to rewrite absolute paths within the output
350 directory into relative paths. Note that only paths within the
351 output directory will be rewritten; therefore, if you change
352 BR2_HOST_DIR to point outside the output directory and
353 subsequently move it to a different location, this will lead
356 This option has as a result that the debug information in the
357 object files also has only relative paths. Therefore, make
358 sure you cd to the build directory before starting gdb. See
359 the section "COMPILING IN DIFFERENT DIRECTORIES" in the ccache
360 manual for more information.
364 config BR2_ENABLE_DEBUG
365 bool "build packages with debugging symbols"
367 Build packages with debugging symbols enabled. All libraries
368 and binaries in the 'staging' directory will have debugging
369 symbols, which allows remote debugging even if libraries and
370 binaries are stripped on the target. Whether libraries and
371 binaries are stripped on the target is controlled by the
372 BR2_STRIP_* options below.
376 prompt "gcc debug level"
379 Set the debug level for gcc
384 Debug level 1 produces minimal information, enough for making
385 backtraces in parts of the program that you don't plan to
386 debug. This includes descriptions of functions and external
387 variables, but no information about local variables and no
393 The default gcc debug level is 2
398 Level 3 includes extra information, such as all the macro
399 definitions present in the program. Some debuggers support
400 macro expansion when you use -g3.
405 prompt "strip command for binaries on target"
406 default BR2_STRIP_strip
408 config BR2_STRIP_strip
410 depends on !BR2_PACKAGE_HOST_ELF2FLT
412 Binaries and libraries in the target filesystem will be
413 stripped using the normal 'strip' command. This allows to save
414 space, mainly by removing debugging symbols. Debugging symbols
415 on the target are needed for native debugging, but not when
416 remote debugging is used.
418 config BR2_STRIP_none
421 Do not strip binaries and libraries in the target filesystem.
424 config BR2_STRIP_EXCLUDE_FILES
425 string "executables that should not be stripped"
426 depends on !BR2_STRIP_none
429 You may specify a space-separated list of binaries and
430 libraries here that should not be stripped on the target.
432 config BR2_STRIP_EXCLUDE_DIRS
433 string "directories that should be skipped when stripping"
434 depends on !BR2_STRIP_none
437 You may specify a space-separated list of directories that
438 should be skipped when stripping. Binaries and libraries in
439 these directories will not be touched. The directories should
440 be specified relative to the target directory, without leading
444 prompt "gcc optimization level"
445 default BR2_OPTIMIZE_S
447 Set the optimization level for gcc
449 config BR2_OPTIMIZE_0
450 bool "optimization level 0"
452 Do not optimize. This is the default.
454 config BR2_OPTIMIZE_1
455 bool "optimization level 1"
457 Optimize. Optimizing compilation takes somewhat more time, and
458 a lot more memory for a large function. With -O, the compiler
459 tries to reduce code size and execution time, without
460 performing any optimizations that take a great deal of
461 compilation time. -O turns on the following optimization
462 flags: -fdefer-pop -fdelayed-branch -fguess-branch-probability
463 -fcprop-registers -floop-optimize -fif-conversion
464 -fif-conversion2 -ftree-ccp -ftree-dce -ftree-dominator-opts
465 -ftree-dse -ftree-ter -ftree-lrs -ftree-sra -ftree-copyrename
466 -ftree-fre -ftree-ch -funit-at-a-time -fmerge-constants. -O
467 also turns on -fomit-frame-pointer on machines where doing so
468 does not interfere with debugging.
470 config BR2_OPTIMIZE_2
471 bool "optimization level 2"
473 Optimize even more. GCC performs nearly all supported
474 optimizations that do not involve a space-speed tradeoff. The
475 compiler does not perform loop unrolling or function inlining
476 when you specify -O2. As compared to -O, this option increases
477 both compilation time and the performance of the generated
478 code. -O2 turns on all optimization flags specified by -O. It
479 also turns on the following optimization flags:
480 -fthread-jumps -fcrossjumping -foptimize-sibling-calls
481 -fcse-follow-jumps -fcse-skip-blocks -fgcse -fgcse-lm
482 -fexpensive-optimizations -fstrength-reduce
483 -frerun-cse-after-loop -frerun-loop-opt -fcaller-saves
484 -fpeephole2 -fschedule-insns -fschedule-insns2
485 -fsched-interblock -fsched-spec -fregmove -fstrict-aliasing
486 -fdelete-null-pointer-checks -freorder-blocks
487 -freorder-functions -falign-functions -falign-jumps
488 -falign-loops -falign-labels -ftree-vrp -ftree-pre. Please
489 note the warning under -fgcse about invoking -O2 on programs
490 that use computed gotos.
492 config BR2_OPTIMIZE_3
493 bool "optimization level 3"
495 Optimize yet more. -O3 turns on all optimizations specified by
496 -O2 and also turns on the -finline-functions, -funswitch-loops
497 and -fgcse-after-reload options.
499 config BR2_OPTIMIZE_G
500 bool "optimize for debugging"
501 depends on BR2_TOOLCHAIN_GCC_AT_LEAST_4_8
503 Optimize for debugging. This enables optimizations that do not
504 interfere with debugging. It should be the optimization level
505 of choice for the standard edit-compile-debug cycle, offering
506 a reasonable level of optimization while maintaining fast
507 compilation and a good debugging experience.
509 config BR2_OPTIMIZE_S
510 bool "optimize for size"
512 Optimize for size. -Os enables all -O2 optimizations that do
513 not typically increase code size. It also performs further
514 optimizations designed to reduce code size. -Os disables the
515 following optimization flags: -falign-functions -falign-jumps
516 -falign-loops -falign-labels -freorder-blocks
517 -freorder-blocks-and-partition -fprefetch-loop-arrays
518 -ftree-vect-loop-version
522 config BR2_GOOGLE_BREAKPAD_ENABLE
523 bool "Enable google-breakpad support"
524 select BR2_PACKAGE_GOOGLE_BREAKPAD
525 depends on BR2_INSTALL_LIBSTDCPP
526 depends on BR2_USE_WCHAR
527 depends on BR2_TOOLCHAIN_HAS_THREADS
528 depends on (BR2_TOOLCHAIN_USES_GLIBC || BR2_TOOLCHAIN_USES_UCLIBC)
529 depends on BR2_PACKAGE_GOOGLE_BREAKPAD_ARCH_SUPPORTS
531 This option will enable the use of google breakpad, a library
532 and tool suite that allows you to distribute an application to
533 users with compiler-provided debugging information removed,
534 record crashes in compact "minidump" files, send them back to
535 your server and produce C and C++ stack traces from these
536 minidumps. Breakpad can also write minidumps on request for
537 programs that have not crashed.
539 if BR2_GOOGLE_BREAKPAD_ENABLE
541 config BR2_GOOGLE_BREAKPAD_INCLUDE_FILES
542 string "List of executables and libraries to extract symbols from"
545 You may specify a space-separated list of binaries and
546 libraries with full paths relative to $(TARGET_DIR) of which
547 debug symbols will be dumped for further use with google
550 A directory structure that can be used by minidump-stackwalk
553 $(STAGING_DIR)/usr/share/google-breakpad-symbols
558 bool "build code with Stack Smashing Protection"
559 default BR2_SSP_ALL if BR2_ENABLE_SSP # legacy
560 depends on BR2_TOOLCHAIN_HAS_SSP
562 Enable stack smashing protection support using GCC's
563 -fstack-protector option family.
566 http://www.linuxfromscratch.org/hints/downloads/files/ssp.txt
569 Note that this requires the toolchain to have SSP support.
570 This is always the case for glibc and eglibc toolchain, but is
571 optional in uClibc toolchains.
576 Disable stack-smashing protection.
578 config BR2_SSP_REGULAR
579 bool "-fstack-protector"
581 Emit extra code to check for buffer overflows, such as stack
582 smashing attacks. This is done by adding a guard variable to
583 functions with vulnerable objects. This includes functions
584 that call alloca, and functions with buffers larger than 8
585 bytes. The guards are initialized when a function is entered
586 and then checked when the function exits. If a guard check
587 fails, an error message is printed and the program exits.
589 config BR2_SSP_STRONG
590 bool "-fstack-protector-strong"
591 depends on BR2_TOOLCHAIN_GCC_AT_LEAST_4_9
593 Like -fstack-protector but includes additional functions to be
594 protected - those that have local array definitions, or have
595 references to local frame addresses.
597 comment "Stack Smashing Protection strong needs a toolchain w/ gcc >= 4.9"
598 depends on !BR2_TOOLCHAIN_GCC_AT_LEAST_4_9
601 bool "-fstack-protector-all"
603 Like -fstack-protector except that all functions are
604 protected. This option might have a significant performance
605 impact on the compiled binaries.
609 comment "Stack Smashing Protection needs a toolchain w/ SSP"
610 depends on !BR2_TOOLCHAIN_HAS_SSP
614 default BR2_SHARED_LIBS if BR2_BINFMT_SUPPORTS_SHARED
615 default BR2_STATIC_LIBS if !BR2_BINFMT_SUPPORTS_SHARED
617 Select the type of libraries you want to use on the target.
619 The default is to build dynamic libraries and use those on the
620 target filesystem, except when the architecture and/or the
621 selected binary format does not support shared libraries.
623 config BR2_STATIC_LIBS
626 Build and use only static libraries. No shared libraries will
627 be installed on the target. This potentially increases your
628 code size and should only be used if you know what you are
629 doing. Note that some packages may not be available when this
630 option is enabled, due to their need for dynamic library
633 config BR2_SHARED_LIBS
635 depends on BR2_BINFMT_SUPPORTS_SHARED
637 Build and use only shared libraries. This is the recommended
638 solution as it saves space and build time.
640 config BR2_SHARED_STATIC_LIBS
641 bool "both static and shared"
642 depends on BR2_BINFMT_SUPPORTS_SHARED
644 Build both shared and static libraries, but link executables
645 dynamically. While building both shared and static libraries
646 take more time and more disk space, having static libraries
647 may be useful to link some of the applications statically.
652 config BR2_PACKAGE_OVERRIDE_FILE
653 string "location of a package override file"
654 default "$(CONFIG_DIR)/local.mk"
656 A package override file is a short makefile that contains
657 variable definitions of the form <pkg>_OVERRIDE_SRCDIR, which
658 allows to tell Buildroot to use an existing directory as the
659 source directory for a particular package. See the Buildroot
660 documentation for more details on this feature.
662 config BR2_GLOBAL_PATCH_DIR
663 string "global patch directories"
665 You may specify a space separated list of one or more
666 directories containing global package patches. For a specific
667 version <packageversion> of a specific package <packagename>,
668 patches are applied as follows:
670 First, the default Buildroot patch set for the package is
671 applied from the package's directory in Buildroot.
673 Then for every directory - <global-patch-dir> - that exists in
674 BR2_GLOBAL_PATCH_DIR, if the directory
675 <global-patch-dir>/<packagename>/<packageversion>/ exists,
676 then all *.patch files in this directory will be applied.
678 Otherwise, if the directory <global-patch-dir>/<packagename>
679 exists, then all *.patch files in the directory will be
684 config BR2_COMPILER_PARANOID_UNSAFE_PATH
685 bool "paranoid check of library/header paths"
688 By default, when this option is disabled, when the Buildroot
689 cross-compiler will encounter an unsafe library or header path
690 (such as /usr/include, or /usr/lib), the compiler will display
693 By enabling this option, this warning is turned into an error,
694 which will completely abort the build when such unsafe paths
697 Note that this mechanism is available for both the internal
698 toolchain (through the toolchain wrapper and binutils patches)
699 and external toolchain backends (through the toolchain wrapper).
701 config BR2_REPRODUCIBLE
702 bool "Make the build reproducible (experimental)"
704 This option will remove all sources of non-reproducibility
705 from the build process. For a given Buildroot configuration,
706 this allows to generate exactly identical binaries from one
707 build to the other, including on different machines.
709 This is labeled as an experimental feature, as not all
710 packages behave properly to ensure reproducibility.
716 source "toolchain/Config.in"
718 source "system/Config.in"
720 source "linux/Config.in"
722 source "package/Config.in"
724 source "fs/Config.in"
726 source "boot/Config.in"
728 source "package/Config.in.host"
730 source "Config.in.legacy"
732 menu "User-provided options"
733 depends on BR2_EXTERNAL != "support/dummy-external"
735 source "$BR2_EXTERNAL/Config.in"
739 source "$BR2_BUILD_DIR/.br2-external.in"