Makefile help example

help:
    @echo 'Cleaning:'
    @echo '  clean                  - delete all files created by build'
    @echo '  distclean              - delete all non-source files (including .config)'
    @echo
    @echo 'Build:'
    @echo '  all                    - make world'
    @echo '  toolchain              - build toolchain'
    @echo '  sdk                    - build relocatable SDK'
    @echo
    @echo 'Configuration:'
    @echo '  menuconfig             - interactive curses-based configurator'
    @echo '  nconfig                - interactive ncurses-based configurator'
    @echo '  xconfig                - interactive Qt-based configurator'
    @echo '  gconfig                - interactive GTK-based configurator'
    @echo '  oldconfig              - resolve any unresolved symbols in .config'
    @echo '  silentoldconfig        - Same as oldconfig, but quietly, additionally update deps'
    @echo '  olddefconfig           - Same as silentoldconfig but sets new symbols to their default value'
    @echo '  randconfig             - New config with random answer to all options'
    @echo '  defconfig              - New config with default answer to all options'
    @echo '                             BR2_DEFCONFIG, if set, is used as input'
    @echo '  savedefconfig          - Save current config to BR2_DEFCONFIG (minimal config)'
    @echo '  allyesconfig           - New config where all options are accepted with yes'
    @echo '  allnoconfig            - New config where all options are answered with no'
    @echo '  alldefconfig           - New config where all options are set to default'
    @echo '  randpackageconfig      - New config with random answer to package options'
    @echo '  allyespackageconfig    - New config where pkg options are accepted with yes'
    @echo '  allnopackageconfig     - New config where package options are answered with no'
    @echo
    @echo 'Package-specific:'
    @echo '  <pkg>                  - Build and install <pkg> and all its dependencies'
    @echo '  <pkg>-source           - Only download the source files for <pkg>'
    @echo '  <pkg>-extract          - Extract <pkg> sources'
    @echo '  <pkg>-patch            - Apply patches to <pkg>'
    @echo '  <pkg>-depends          - Build <pkg>'\''s dependencies'
    @echo '  <pkg>-configure        - Build <pkg> up to the configure step'
    @echo '  <pkg>-build            - Build <pkg> up to the build step'
    @echo '  <pkg>-show-depends     - List packages on which <pkg> depends'
    @echo '  <pkg>-show-rdepends    - List packages which have <pkg> as a dependency'
    @echo '  <pkg>-graph-depends    - Generate a graph of <pkg>'\''s dependencies'
    @echo '  <pkg>-graph-rdepends   - Generate a graph of <pkg>'\''s reverse dependencies'
    @echo '  <pkg>-dirclean         - Remove <pkg> build directory'
    @echo '  <pkg>-reconfigure      - Restart the build from the configure step'
    @echo '  <pkg>-rebuild          - Restart the build from the build step'
    $(foreach p,$(HELP_PACKAGES), \
        @echo $(sep) \
        @echo '$($(p)_NAME):' $(sep) \
        $($(p)_HELP_CMDS)$(sep))
    @echo
    @echo 'Documentation:'
    @echo '  manual                 - build manual in all formats'
    @echo '  manual-html            - build manual in HTML'
    @echo '  manual-split-html      - build manual in split HTML'
    @echo '  manual-pdf             - build manual in PDF'
    @echo '  manual-text            - build manual in text'
    @echo '  manual-epub            - build manual in ePub'
    @echo '  graph-build            - generate graphs of the build times'
    @echo '  graph-depends          - generate graph of the dependency tree'
    @echo '  graph-size             - generate stats of the filesystem size'
    @echo '  list-defconfigs        - list all defconfigs (pre-configured minimal systems)'
    @echo
    @echo 'Miscellaneous:'
    @echo '  source                 - download all sources needed for offline-build'
    @echo '  source-check           - check selected packages for valid download URLs'
    @echo '  external-deps          - list external packages used'
    @echo '  legal-info             - generate info about license compliance'
    @echo '  printvars              - dump all the internal variables'
    @echo
    @echo '  make V=0|1             - 0 => quiet build (default), 1 => verbose build'
    @echo '  make O=dir             - Locate all output files in "dir", including .config'
    @echo
    @echo 'For further details, see README, generate the Buildroot manual, or consult'
    @echo 'it on-line at http://buildroot.org/docs.html'
    @echo