3 mainmenu "Buildroot $BR2_VERSION Configuration"
5 config BR2_HAVE_DOT_CONFIG
11 option env="BR2_VERSION_FULL"
19 option env="BUILD_DIR"
21 # Hidden config symbols for packages to check system gcc version
22 config BR2_HOST_GCC_VERSION
24 option env="HOST_GCC_VERSION"
26 config BR2_HOST_GCC_AT_LEAST_4_5
28 default y if BR2_HOST_GCC_VERSION = "4 5"
30 config BR2_HOST_GCC_AT_LEAST_4_6
32 default y if BR2_HOST_GCC_VERSION = "4 6"
33 select BR2_HOST_GCC_AT_LEAST_4_5
35 config BR2_HOST_GCC_AT_LEAST_4_7
37 default y if BR2_HOST_GCC_VERSION = "4 7"
38 select BR2_HOST_GCC_AT_LEAST_4_6
40 config BR2_HOST_GCC_AT_LEAST_4_8
42 default y if BR2_HOST_GCC_VERSION = "4 8"
43 select BR2_HOST_GCC_AT_LEAST_4_7
45 config BR2_HOST_GCC_AT_LEAST_4_9
47 default y if BR2_HOST_GCC_VERSION = "4 9"
48 select BR2_HOST_GCC_AT_LEAST_4_8
50 config BR2_HOST_GCC_AT_LEAST_5
52 default y if BR2_HOST_GCC_VERSION = "5"
53 select BR2_HOST_GCC_AT_LEAST_4_9
55 config BR2_HOST_GCC_AT_LEAST_6
57 default y if BR2_HOST_GCC_VERSION = "6"
58 select BR2_HOST_GCC_AT_LEAST_5
60 # Hidden boolean selected by packages in need of Java in order to build
62 config BR2_NEEDS_HOST_JAVA
65 # Hidden boolean selected by packages in need of javac in order to build
66 # (example: classpath)
67 config BR2_NEEDS_HOST_JAVAC
70 # Hidden boolean selected by packages in need of jar in order to build
71 # (example: classpath)
72 config BR2_NEEDS_HOST_JAR
75 # Hidden boolean selected by pre-built packages for x86, when they
76 # need to run on x86-64 machines (example: pre-built external
77 # toolchains, binary tools like SAM-BA, etc.).
78 config BR2_HOSTARCH_NEEDS_IA32_LIBS
81 # Hidden boolean selected by packages that need to build 32 bits
82 # binaries with the host compiler, even on 64 bits build machines (e.g
84 config BR2_HOSTARCH_NEEDS_IA32_COMPILER
87 # Hidden boolean selected by packages that need the host to have an
89 config BR2_NEEDS_HOST_UTF8_LOCALE
92 source "arch/Config.in"
100 default "wget --passive-ftp -nd -t 3"
103 string "Subversion (svn) command"
107 string "Bazaar (bzr) command"
118 config BR2_LOCALFILES
119 string "Local files retrieval command"
123 string "Secure copy (scp) command"
127 string "Secure shell (ssh) command"
131 string "Mercurial (hg) command"
135 string "zcat command"
138 Command to be used to extract a gzip'ed file to stdout. zcat
139 is identical to gunzip -c except that the former may not be
140 available on your system.
141 Default is "gzip -d -c"
142 Other possible values include "gunzip -c" or "zcat".
145 string "bzcat command"
148 Command to be used to extract a bzip2'ed file to stdout.
149 bzcat is identical to bunzip2 -c except that the former may
150 not be available on your system.
152 Other possible values include "bunzip2 -c" or "bzip2 -d -c".
155 string "xzcat command"
158 Command to be used to extract a xz'ed file to stdout.
162 string "lzcat command"
165 Command to be used to extract a lzip'ed file to stdout.
166 Default is "lzip -d -c"
168 config BR2_TAR_OPTIONS
172 Options to pass to tar when extracting the sources.
173 E.g. " -v --exclude='*.svn*'" to exclude all .svn internal files
178 config BR2_DEFCONFIG_FROM_ENV
180 option env="BR2_DEFCONFIG"
183 string "Location to save buildroot config"
184 default BR2_DEFCONFIG_FROM_ENV if BR2_DEFCONFIG_FROM_ENV != ""
185 default "$(CONFIG_DIR)/defconfig"
187 When running 'make savedefconfig', the defconfig file will be
188 saved in this location.
191 string "Download dir"
192 default "$(TOPDIR)/dl"
194 Directory to store all the source files that we need to fetch.
195 If the Linux shell environment has defined the BR2_DL_DIR
196 environment variable, then this overrides this configuration
199 The default is $(TOPDIR)/dl
203 default "$(BASE_DIR)/host"
205 Directory to store all the binary files that are built for the
206 host. This includes the cross compilation toolchain when
207 building the internal buildroot toolchain.
209 The default is $(BASE_DIR)/host
211 menu "Mirrors and Download locations"
213 config BR2_PRIMARY_SITE
214 string "Primary download site"
217 Primary site to download from. If this option is set then
218 buildroot will try to download package source first from this
219 site and try the default if the file is not found.
221 - URIs recognized by $(WGET)
222 - local URIs of the form file://absolutepath
223 - scp URIs of the form scp://[user@]host:path.
225 config BR2_PRIMARY_SITE_ONLY
226 bool "Only allow downloads from primary download site"
227 depends on BR2_PRIMARY_SITE != ""
229 If this option is enabled, downloads will only be attempted
230 from the primary download site. Other locations, like the
231 package's official download location or the backup download
232 site, will not be considered. Therefore, if the package is not
233 present on the primary site, the download fails.
235 This is useful for project developers who want to ensure that
236 the project can be built even if the upstream tarball
239 if !BR2_PRIMARY_SITE_ONLY
241 config BR2_BACKUP_SITE
242 string "Backup download site"
243 default "http://sources.buildroot.net"
245 Backup site to download from. If this option is set then
246 buildroot will fall back to download package sources from here
247 if the normal location fails.
249 config BR2_KERNEL_MIRROR
250 string "Kernel.org mirror"
251 default "https://cdn.kernel.org/pub"
253 kernel.org is mirrored on a number of servers around the
254 world. The following allows you to select your preferred
255 mirror. By default, a CDN is used, which automatically
256 redirects to a mirror geographically close to you.
258 Have a look on the kernel.org site for a list of mirrors, then
259 enter the URL to the base directory. Examples:
261 http://www.XX.kernel.org/pub (XX = country code)
262 http://mirror.aarnet.edu.au/pub/ftp.kernel.org
264 config BR2_GNU_MIRROR
265 string "GNU Software mirror"
266 default "http://ftpmirror.gnu.org"
268 GNU has multiple software mirrors scattered around the
269 world. The following allows you to select your preferred
270 mirror. By default, a generic address is used, which
271 automatically selects an up-to-date and local mirror.
273 Have a look on the gnu.org site for a list of mirrors, then
274 enter the URL to the base directory. Examples:
276 http://ftp.gnu.org/pub/gnu
277 http://mirror.aarnet.edu.au/pub/gnu
279 config BR2_LUAROCKS_MIRROR
280 string "LuaRocks mirror"
281 default "http://rocks.moonscript.org"
285 See http://luarocks.org
287 config BR2_CPAN_MIRROR
288 string "CPAN mirror (Perl packages)"
289 default "http://cpan.metacpan.org"
291 CPAN (Comprehensive Perl Archive Network) is a repository of
292 Perl packages. It has multiple software mirrors scattered
293 around the world. This option allows you to select a mirror.
295 The list of mirrors is available at:
296 http://search.cpan.org/mirror
303 int "Number of jobs to run simultaneously (0 for auto)"
306 Number of jobs to run simultaneously. If 0, determine
307 automatically according to number of CPUs on the host system.
310 bool "Enable compiler cache"
312 This option will enable the use of ccache, a compiler cache.
313 It will cache the result of previous builds to speed up future
314 builds. By default, the cache is stored in
315 $HOME/.buildroot-ccache.
317 Note that Buildroot does not try to invalidate the cache
318 contents when the compiler changes in an incompatible way.
319 Therefore, if you make a change to the compiler version and/or
320 configuration, you are responsible for purging the ccache
321 cache by removing the $HOME/.buildroot-ccache directory.
325 config BR2_CCACHE_DIR
326 string "Compiler cache location"
327 default "$(HOME)/.buildroot-ccache"
329 Where ccache should store cached files.
331 config BR2_CCACHE_INITIAL_SETUP
332 string "Compiler cache initial setup"
334 Initial ccache settings to apply, such as --max-files or
337 For example, if your project is known to require more space
338 than the default max cache size, then you might want to
339 increase the cache size to a suitable amount using the -M
342 The string you specify here is passed verbatim to ccache.
343 Refer to ccache documentation for more details.
345 These initial settings are applied after ccache has been
348 config BR2_CCACHE_USE_BASEDIR
349 bool "Use relative paths"
352 Allow ccache to convert absolute paths within the output
353 directory into relative paths.
355 During the build, many -I include directives are given with an
356 absolute path. These absolute paths end up in the hashes that
357 are computed by ccache. Therefore, when you build from a
358 different directory, the hash will be different and the cached
359 object will not be used.
361 To improve cache performance, set this option to y. This
362 allows ccache to rewrite absolute paths within the output
363 directory into relative paths. Note that only paths within the
364 output directory will be rewritten; therefore, if you change
365 BR2_HOST_DIR to point outside the output directory and
366 subsequently move it to a different location, this will lead
369 This option has as a result that the debug information in the
370 object files also has only relative paths. Therefore, make
371 sure you cd to the build directory before starting gdb. See
372 the section "COMPILING IN DIFFERENT DIRECTORIES" in the ccache
373 manual for more information.
377 config BR2_ENABLE_DEBUG
378 bool "build packages with debugging symbols"
380 Build packages with debugging symbols enabled. All libraries
381 and binaries in the 'staging' directory will have debugging
382 symbols, which allows remote debugging even if libraries and
383 binaries are stripped on the target. Whether libraries and
384 binaries are stripped on the target is controlled by the
385 BR2_STRIP_* options below.
389 prompt "gcc debug level"
392 Set the debug level for gcc
397 Debug level 1 produces minimal information, enough for making
398 backtraces in parts of the program that you don't plan to
399 debug. This includes descriptions of functions and external
400 variables, but no information about local variables and no
406 The default gcc debug level is 2
411 Level 3 includes extra information, such as all the macro
412 definitions present in the program. Some debuggers support
413 macro expansion when you use -g3.
418 prompt "strip command for binaries on target"
419 default BR2_STRIP_strip
421 config BR2_STRIP_strip
423 depends on !BR2_PACKAGE_HOST_ELF2FLT
425 Binaries and libraries in the target filesystem will be
426 stripped using the normal 'strip' command. This allows to save
427 space, mainly by removing debugging symbols. Debugging symbols
428 on the target are needed for native debugging, but not when
429 remote debugging is used.
431 config BR2_STRIP_none
434 Do not strip binaries and libraries in the target filesystem.
437 config BR2_STRIP_EXCLUDE_FILES
438 string "executables that should not be stripped"
439 depends on !BR2_STRIP_none
442 You may specify a space-separated list of binaries and
443 libraries here that should not be stripped on the target.
445 config BR2_STRIP_EXCLUDE_DIRS
446 string "directories that should be skipped when stripping"
447 depends on !BR2_STRIP_none
450 You may specify a space-separated list of directories that
451 should be skipped when stripping. Binaries and libraries in
452 these directories will not be touched. The directories should
453 be specified relative to the target directory, without leading
457 prompt "gcc optimization level"
458 default BR2_OPTIMIZE_S
460 Set the optimization level for gcc
462 config BR2_OPTIMIZE_0
463 bool "optimization level 0"
465 Do not optimize. This is the default.
467 config BR2_OPTIMIZE_1
468 bool "optimization level 1"
470 Optimize. Optimizing compilation takes somewhat more time, and
471 a lot more memory for a large function. With -O, the compiler
472 tries to reduce code size and execution time, without
473 performing any optimizations that take a great deal of
474 compilation time. -O turns on the following optimization
475 flags: -fdefer-pop -fdelayed-branch -fguess-branch-probability
476 -fcprop-registers -floop-optimize -fif-conversion
477 -fif-conversion2 -ftree-ccp -ftree-dce -ftree-dominator-opts
478 -ftree-dse -ftree-ter -ftree-lrs -ftree-sra -ftree-copyrename
479 -ftree-fre -ftree-ch -funit-at-a-time -fmerge-constants. -O
480 also turns on -fomit-frame-pointer on machines where doing so
481 does not interfere with debugging.
483 config BR2_OPTIMIZE_2
484 bool "optimization level 2"
486 Optimize even more. GCC performs nearly all supported
487 optimizations that do not involve a space-speed tradeoff. The
488 compiler does not perform loop unrolling or function inlining
489 when you specify -O2. As compared to -O, this option increases
490 both compilation time and the performance of the generated
491 code. -O2 turns on all optimization flags specified by -O. It
492 also turns on the following optimization flags:
493 -fthread-jumps -fcrossjumping -foptimize-sibling-calls
494 -fcse-follow-jumps -fcse-skip-blocks -fgcse -fgcse-lm
495 -fexpensive-optimizations -fstrength-reduce
496 -frerun-cse-after-loop -frerun-loop-opt -fcaller-saves
497 -fpeephole2 -fschedule-insns -fschedule-insns2
498 -fsched-interblock -fsched-spec -fregmove -fstrict-aliasing
499 -fdelete-null-pointer-checks -freorder-blocks
500 -freorder-functions -falign-functions -falign-jumps
501 -falign-loops -falign-labels -ftree-vrp -ftree-pre. Please
502 note the warning under -fgcse about invoking -O2 on programs
503 that use computed gotos.
505 config BR2_OPTIMIZE_3
506 bool "optimization level 3"
508 Optimize yet more. -O3 turns on all optimizations specified by
509 -O2 and also turns on the -finline-functions, -funswitch-loops
510 and -fgcse-after-reload options.
512 config BR2_OPTIMIZE_G
513 bool "optimize for debugging"
514 depends on BR2_TOOLCHAIN_GCC_AT_LEAST_4_8
516 Optimize for debugging. This enables optimizations that do not
517 interfere with debugging. It should be the optimization level
518 of choice for the standard edit-compile-debug cycle, offering
519 a reasonable level of optimization while maintaining fast
520 compilation and a good debugging experience.
522 config BR2_OPTIMIZE_S
523 bool "optimize for size"
525 Optimize for size. -Os enables all -O2 optimizations that do
526 not typically increase code size. It also performs further
527 optimizations designed to reduce code size. -Os disables the
528 following optimization flags: -falign-functions -falign-jumps
529 -falign-loops -falign-labels -freorder-blocks
530 -freorder-blocks-and-partition -fprefetch-loop-arrays
531 -ftree-vect-loop-version
535 config BR2_GOOGLE_BREAKPAD_ENABLE
536 bool "Enable google-breakpad support"
537 select BR2_PACKAGE_GOOGLE_BREAKPAD
538 depends on BR2_INSTALL_LIBSTDCPP
539 depends on BR2_HOST_GCC_AT_LEAST_4_8 # C++11
540 depends on BR2_TOOLCHAIN_GCC_AT_LEAST_4_8 # C++11
541 depends on BR2_USE_WCHAR
542 depends on BR2_TOOLCHAIN_HAS_THREADS
543 depends on (BR2_TOOLCHAIN_USES_GLIBC || BR2_TOOLCHAIN_USES_UCLIBC)
544 depends on BR2_PACKAGE_GOOGLE_BREAKPAD_ARCH_SUPPORTS
546 This option will enable the use of google breakpad, a library
547 and tool suite that allows you to distribute an application to
548 users with compiler-provided debugging information removed,
549 record crashes in compact "minidump" files, send them back to
550 your server and produce C and C++ stack traces from these
551 minidumps. Breakpad can also write minidumps on request for
552 programs that have not crashed.
554 if BR2_GOOGLE_BREAKPAD_ENABLE
556 config BR2_GOOGLE_BREAKPAD_INCLUDE_FILES
557 string "List of executables and libraries to extract symbols from"
560 You may specify a space-separated list of binaries and
561 libraries with full paths relative to $(TARGET_DIR) of which
562 debug symbols will be dumped for further use with google
565 A directory structure that can be used by minidump-stackwalk
568 $(STAGING_DIR)/usr/share/google-breakpad-symbols
573 bool "build code with Stack Smashing Protection"
574 default BR2_SSP_ALL if BR2_ENABLE_SSP # legacy
575 depends on BR2_TOOLCHAIN_HAS_SSP
577 Enable stack smashing protection support using GCC's
578 -fstack-protector option family.
581 http://www.linuxfromscratch.org/hints/downloads/files/ssp.txt
584 Note that this requires the toolchain to have SSP support.
585 This is always the case for glibc and eglibc toolchain, but is
586 optional in uClibc toolchains.
591 Disable stack-smashing protection.
593 config BR2_SSP_REGULAR
594 bool "-fstack-protector"
596 Emit extra code to check for buffer overflows, such as stack
597 smashing attacks. This is done by adding a guard variable to
598 functions with vulnerable objects. This includes functions
599 that call alloca, and functions with buffers larger than 8
600 bytes. The guards are initialized when a function is entered
601 and then checked when the function exits. If a guard check
602 fails, an error message is printed and the program exits.
604 config BR2_SSP_STRONG
605 bool "-fstack-protector-strong"
606 depends on BR2_TOOLCHAIN_GCC_AT_LEAST_4_9
608 Like -fstack-protector but includes additional functions to be
609 protected - those that have local array definitions, or have
610 references to local frame addresses.
612 comment "Stack Smashing Protection strong needs a toolchain w/ gcc >= 4.9"
613 depends on !BR2_TOOLCHAIN_GCC_AT_LEAST_4_9
616 bool "-fstack-protector-all"
618 Like -fstack-protector except that all functions are
619 protected. This option might have a significant performance
620 impact on the compiled binaries.
624 comment "Stack Smashing Protection needs a toolchain w/ SSP"
625 depends on !BR2_TOOLCHAIN_HAS_SSP
629 default BR2_SHARED_LIBS if BR2_BINFMT_SUPPORTS_SHARED
630 default BR2_STATIC_LIBS if !BR2_BINFMT_SUPPORTS_SHARED
632 Select the type of libraries you want to use on the target.
634 The default is to build dynamic libraries and use those on the
635 target filesystem, except when the architecture and/or the
636 selected binary format does not support shared libraries.
638 config BR2_STATIC_LIBS
641 Build and use only static libraries. No shared libraries will
642 be installed on the target. This potentially increases your
643 code size and should only be used if you know what you are
644 doing. Note that some packages may not be available when this
645 option is enabled, due to their need for dynamic library
648 config BR2_SHARED_LIBS
650 depends on BR2_BINFMT_SUPPORTS_SHARED
652 Build and use only shared libraries. This is the recommended
653 solution as it saves space and build time.
655 config BR2_SHARED_STATIC_LIBS
656 bool "both static and shared"
657 depends on BR2_BINFMT_SUPPORTS_SHARED
659 Build both shared and static libraries, but link executables
660 dynamically. While building both shared and static libraries
661 take more time and more disk space, having static libraries
662 may be useful to link some of the applications statically.
667 config BR2_PACKAGE_OVERRIDE_FILE
668 string "location of a package override file"
669 default "$(CONFIG_DIR)/local.mk"
671 A package override file is a short makefile that contains
672 variable definitions of the form <pkg>_OVERRIDE_SRCDIR, which
673 allows to tell Buildroot to use an existing directory as the
674 source directory for a particular package. See the Buildroot
675 documentation for more details on this feature.
677 config BR2_GLOBAL_PATCH_DIR
678 string "global patch directories"
680 You may specify a space separated list of one or more
681 directories containing global package patches. For a specific
682 version <packageversion> of a specific package <packagename>,
683 patches are applied as follows:
685 First, the default Buildroot patch set for the package is
686 applied from the package's directory in Buildroot.
688 Then for every directory - <global-patch-dir> - that exists in
689 BR2_GLOBAL_PATCH_DIR, if the directory
690 <global-patch-dir>/<packagename>/<packageversion>/ exists,
691 then all *.patch files in this directory will be applied.
693 Otherwise, if the directory <global-patch-dir>/<packagename>
694 exists, then all *.patch files in the directory will be
699 config BR2_COMPILER_PARANOID_UNSAFE_PATH
700 bool "paranoid check of library/header paths"
703 By default, when this option is disabled, when the Buildroot
704 cross-compiler will encounter an unsafe library or header path
705 (such as /usr/include, or /usr/lib), the compiler will display
708 By enabling this option, this warning is turned into an error,
709 which will completely abort the build when such unsafe paths
712 Note that this mechanism is available for both the internal
713 toolchain (through the toolchain wrapper and binutils patches)
714 and external toolchain backends (through the toolchain wrapper).
716 config BR2_REPRODUCIBLE
717 bool "Make the build reproducible (experimental)"
719 This option will remove all sources of non-reproducibility
720 from the build process. For a given Buildroot configuration,
721 this allows to generate exactly identical binaries from one
722 build to the other, including on different machines.
724 The current implementation is restricted to builds with the
725 same output directory. Many (absolute) paths are recorded in
726 intermediary files, and it is very likely that some of these
727 paths leak into the target rootfs. If you build with the
728 same O=... path, however, the result is identical.
730 This is labeled as an experimental feature, as not all
731 packages behave properly to ensure reproducibility.
737 source "toolchain/Config.in"
739 source "system/Config.in"
741 source "linux/Config.in"
743 source "package/Config.in"
745 source "fs/Config.in"
747 source "boot/Config.in"
749 source "package/Config.in.host"
751 source "Config.in.legacy"
753 source "$BR2_BUILD_DIR/.br2-external.in"