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_DEPRECATED
365 bool "Show options and packages that are deprecated or obsolete"
367 This option shows outdated/obsolete versions of packages and
368 options that are otherwise hidden.
372 config BR2_DEPRECATED_SINCE_2015_11
376 config BR2_DEPRECATED_SINCE_2016_02
380 config BR2_DEPRECATED_SINCE_2016_05
384 config BR2_DEPRECATED_SINCE_2016_08
388 config BR2_DEPRECATED_SINCE_2016_11
394 config BR2_ENABLE_DEBUG
395 bool "build packages with debugging symbols"
397 Build packages with debugging symbols enabled. All libraries
398 and binaries in the 'staging' directory will have debugging
399 symbols, which allows remote debugging even if libraries and
400 binaries are stripped on the target. Whether libraries and
401 binaries are stripped on the target is controlled by the
402 BR2_STRIP_* options below.
406 prompt "gcc debug level"
409 Set the debug level for gcc
414 Debug level 1 produces minimal information, enough for making
415 backtraces in parts of the program that you don't plan to
416 debug. This includes descriptions of functions and external
417 variables, but no information about local variables and no
423 The default gcc debug level is 2
428 Level 3 includes extra information, such as all the macro
429 definitions present in the program. Some debuggers support
430 macro expansion when you use -g3.
435 prompt "strip command for binaries on target"
436 default BR2_STRIP_strip
438 config BR2_STRIP_strip
440 depends on !BR2_PACKAGE_HOST_ELF2FLT
442 Binaries and libraries in the target filesystem will be
443 stripped using the normal 'strip' command. This allows to save
444 space, mainly by removing debugging symbols. Debugging symbols
445 on the target are needed for native debugging, but not when
446 remote debugging is used.
448 config BR2_STRIP_none
451 Do not strip binaries and libraries in the target filesystem.
454 config BR2_STRIP_EXCLUDE_FILES
455 string "executables that should not be stripped"
456 depends on !BR2_STRIP_none
459 You may specify a space-separated list of binaries and
460 libraries here that should not be stripped on the target.
462 config BR2_STRIP_EXCLUDE_DIRS
463 string "directories that should be skipped when stripping"
464 depends on !BR2_STRIP_none
467 You may specify a space-separated list of directories that
468 should be skipped when stripping. Binaries and libraries in
469 these directories will not be touched. The directories should
470 be specified relative to the target directory, without leading
474 prompt "gcc optimization level"
475 default BR2_OPTIMIZE_S
477 Set the optimization level for gcc
479 config BR2_OPTIMIZE_0
480 bool "optimization level 0"
482 Do not optimize. This is the default.
484 config BR2_OPTIMIZE_1
485 bool "optimization level 1"
487 Optimize. Optimizing compilation takes somewhat more time, and
488 a lot more memory for a large function. With -O, the compiler
489 tries to reduce code size and execution time, without
490 performing any optimizations that take a great deal of
491 compilation time. -O turns on the following optimization
492 flags: -fdefer-pop -fdelayed-branch -fguess-branch-probability
493 -fcprop-registers -floop-optimize -fif-conversion
494 -fif-conversion2 -ftree-ccp -ftree-dce -ftree-dominator-opts
495 -ftree-dse -ftree-ter -ftree-lrs -ftree-sra -ftree-copyrename
496 -ftree-fre -ftree-ch -funit-at-a-time -fmerge-constants. -O
497 also turns on -fomit-frame-pointer on machines where doing so
498 does not interfere with debugging.
500 config BR2_OPTIMIZE_2
501 bool "optimization level 2"
503 Optimize even more. GCC performs nearly all supported
504 optimizations that do not involve a space-speed tradeoff. The
505 compiler does not perform loop unrolling or function inlining
506 when you specify -O2. As compared to -O, this option increases
507 both compilation time and the performance of the generated
508 code. -O2 turns on all optimization flags specified by -O. It
509 also turns on the following optimization flags:
510 -fthread-jumps -fcrossjumping -foptimize-sibling-calls
511 -fcse-follow-jumps -fcse-skip-blocks -fgcse -fgcse-lm
512 -fexpensive-optimizations -fstrength-reduce
513 -frerun-cse-after-loop -frerun-loop-opt -fcaller-saves
514 -fpeephole2 -fschedule-insns -fschedule-insns2
515 -fsched-interblock -fsched-spec -fregmove -fstrict-aliasing
516 -fdelete-null-pointer-checks -freorder-blocks
517 -freorder-functions -falign-functions -falign-jumps
518 -falign-loops -falign-labels -ftree-vrp -ftree-pre. Please
519 note the warning under -fgcse about invoking -O2 on programs
520 that use computed gotos.
522 config BR2_OPTIMIZE_3
523 bool "optimization level 3"
525 Optimize yet more. -O3 turns on all optimizations specified by
526 -O2 and also turns on the -finline-functions, -funswitch-loops
527 and -fgcse-after-reload options.
529 config BR2_OPTIMIZE_G
530 bool "optimize for debugging"
531 depends on BR2_TOOLCHAIN_GCC_AT_LEAST_4_8
533 Optimize for debugging. This enables optimizations that do not
534 interfere with debugging. It should be the optimization level
535 of choice for the standard edit-compile-debug cycle, offering
536 a reasonable level of optimization while maintaining fast
537 compilation and a good debugging experience.
539 config BR2_OPTIMIZE_S
540 bool "optimize for size"
542 Optimize for size. -Os enables all -O2 optimizations that do
543 not typically increase code size. It also performs further
544 optimizations designed to reduce code size. -Os disables the
545 following optimization flags: -falign-functions -falign-jumps
546 -falign-loops -falign-labels -freorder-blocks
547 -freorder-blocks-and-partition -fprefetch-loop-arrays
548 -ftree-vect-loop-version
552 config BR2_GOOGLE_BREAKPAD_ENABLE
553 bool "Enable google-breakpad support"
554 select BR2_PACKAGE_GOOGLE_BREAKPAD
555 depends on BR2_INSTALL_LIBSTDCPP
556 depends on BR2_USE_WCHAR
557 depends on BR2_TOOLCHAIN_HAS_THREADS
558 depends on (BR2_TOOLCHAIN_USES_GLIBC || BR2_TOOLCHAIN_USES_UCLIBC)
559 depends on BR2_PACKAGE_GOOGLE_BREAKPAD_ARCH_SUPPORTS
561 This option will enable the use of google breakpad, a library
562 and tool suite that allows you to distribute an application to
563 users with compiler-provided debugging information removed,
564 record crashes in compact "minidump" files, send them back to
565 your server and produce C and C++ stack traces from these
566 minidumps. Breakpad can also write minidumps on request for
567 programs that have not crashed.
569 if BR2_GOOGLE_BREAKPAD_ENABLE
571 config BR2_GOOGLE_BREAKPAD_INCLUDE_FILES
572 string "List of executables and libraries to extract symbols from"
575 You may specify a space-separated list of binaries and
576 libraries with full paths relative to $(TARGET_DIR) of which
577 debug symbols will be dumped for further use with google
580 A directory structure that can be used by minidump-stackwalk
583 $(STAGING_DIR)/usr/share/google-breakpad-symbols
588 bool "build code with Stack Smashing Protection"
589 default BR2_SSP_ALL if BR2_ENABLE_SSP # legacy
590 depends on BR2_TOOLCHAIN_HAS_SSP
592 Enable stack smashing protection support using GCC's
593 -fstack-protector option family.
596 http://www.linuxfromscratch.org/hints/downloads/files/ssp.txt
599 Note that this requires the toolchain to have SSP support.
600 This is always the case for glibc and eglibc toolchain, but is
601 optional in uClibc toolchains.
606 Disable stack-smashing protection.
608 config BR2_SSP_REGULAR
609 bool "-fstack-protector"
611 Emit extra code to check for buffer overflows, such as stack
612 smashing attacks. This is done by adding a guard variable to
613 functions with vulnerable objects. This includes functions
614 that call alloca, and functions with buffers larger than 8
615 bytes. The guards are initialized when a function is entered
616 and then checked when the function exits. If a guard check
617 fails, an error message is printed and the program exits.
619 config BR2_SSP_STRONG
620 bool "-fstack-protector-strong"
621 depends on BR2_TOOLCHAIN_GCC_AT_LEAST_4_9
623 Like -fstack-protector but includes additional functions to be
624 protected - those that have local array definitions, or have
625 references to local frame addresses.
627 comment "Stack Smashing Protection strong needs a toolchain w/ gcc >= 4.9"
628 depends on !BR2_TOOLCHAIN_GCC_AT_LEAST_4_9
631 bool "-fstack-protector-all"
633 Like -fstack-protector except that all functions are
634 protected. This option might have a significant performance
635 impact on the compiled binaries.
639 comment "Stack Smashing Protection needs a toolchain w/ SSP"
640 depends on !BR2_TOOLCHAIN_HAS_SSP
644 default BR2_SHARED_LIBS if BR2_BINFMT_SUPPORTS_SHARED
645 default BR2_STATIC_LIBS if !BR2_BINFMT_SUPPORTS_SHARED
647 Select the type of libraries you want to use on the target.
649 The default is to build dynamic libraries and use those on the
650 target filesystem, except when the architecture and/or the
651 selected binary format does not support shared libraries.
653 config BR2_STATIC_LIBS
656 Build and use only static libraries. No shared libraries will
657 be installed on the target. This potentially increases your
658 code size and should only be used if you know what you are
659 doing. Note that some packages may not be available when this
660 option is enabled, due to their need for dynamic library
663 config BR2_SHARED_LIBS
665 depends on BR2_BINFMT_SUPPORTS_SHARED
667 Build and use only shared libraries. This is the recommended
668 solution as it saves space and build time.
670 config BR2_SHARED_STATIC_LIBS
671 bool "both static and shared"
672 depends on BR2_BINFMT_SUPPORTS_SHARED
674 Build both shared and static libraries, but link executables
675 dynamically. While building both shared and static libraries
676 take more time and more disk space, having static libraries
677 may be useful to link some of the applications statically.
682 config BR2_PACKAGE_OVERRIDE_FILE
683 string "location of a package override file"
684 default "$(CONFIG_DIR)/local.mk"
686 A package override file is a short makefile that contains
687 variable definitions of the form <pkg>_OVERRIDE_SRCDIR, which
688 allows to tell Buildroot to use an existing directory as the
689 source directory for a particular package. See the Buildroot
690 documentation for more details on this feature.
692 config BR2_GLOBAL_PATCH_DIR
693 string "global patch directories"
695 You may specify a space separated list of one or more
696 directories containing global package patches. For a specific
697 version <packageversion> of a specific package <packagename>,
698 patches are applied as follows:
700 First, the default Buildroot patch set for the package is
701 applied from the package's directory in Buildroot.
703 Then for every directory - <global-patch-dir> - that exists in
704 BR2_GLOBAL_PATCH_DIR, if the directory
705 <global-patch-dir>/<packagename>/<packageversion>/ exists,
706 then all *.patch files in this directory will be applied.
708 Otherwise, if the directory <global-patch-dir>/<packagename>
709 exists, then all *.patch files in the directory will be
714 config BR2_COMPILER_PARANOID_UNSAFE_PATH
715 bool "paranoid check of library/header paths"
718 By default, when this option is disabled, when the Buildroot
719 cross-compiler will encounter an unsafe library or header path
720 (such as /usr/include, or /usr/lib), the compiler will display
723 By enabling this option, this warning is turned into an error,
724 which will completely abort the build when such unsafe paths
727 Note that this mechanism is available for both the internal
728 toolchain (through the toolchain wrapper and binutils patches)
729 and external toolchain backends (through the toolchain wrapper).
731 config BR2_REPRODUCIBLE
732 bool "Make the build reproducible (experimental)"
734 This option will remove all sources of non-reproducibility
735 from the build process. For a given Buildroot configuration,
736 this allows to generate exactly identical binaries from one
737 build to the other, including on different machines.
739 This is labeled as an experimental feature, as not all
740 packages behave properly to ensure reproducibility.
746 source "toolchain/Config.in"
748 source "system/Config.in"
750 source "linux/Config.in"
752 source "package/Config.in"
754 source "fs/Config.in"
756 source "boot/Config.in"
758 source "package/Config.in.host"
760 source "Config.in.legacy"
762 menu "User-provided options"
763 depends on BR2_EXTERNAL != "support/dummy-external"
765 source "$BR2_EXTERNAL/Config.in"
769 source "$BR2_BUILD_DIR/.br2-external.in"