config: add support for <custom>_defconfig

Add support for platform specific and/or custom defconfig
per arch. They have to be suffixed by '_defconfig' and are
automatically detected and displayed by issuing 'make ARCH=<arch> help'.

Signed-off-by: Carmelo Amoroso <carmelo.amoroso@st.com>

diff --git a/Makefile.help b/Makefile.help
index d99cf96..a98d330 100644 (file)
--- a/Makefile.help
+++ b/Makefile.help
@@ -28,6 +28,12 @@ help:
        @echo '  oldconfig              - resolve any unresolved symbols in .config'
        @echo '  silentoldconfig        - resolve any unresolved symbols in .config, silently'
        @echo '  randconfig             - generate a random .config'
+       @$(if $(arch-defconfigs), \
+               @echo ''; \
+               echo 'Architecture specific configs ($(ARCH))'; \
+               $(foreach c, $(arch-defconfigs), \
+                       printf "  %-21s - Build for %s\\n" $(c) $(subst _defconfig,,$(c));) \
+       )
        @echo
        @echo 'Installation:'
        @echo '  install                - install both the runtime and the headers'

diff --git a/Makefile.in b/Makefile.in
index 615ee3e..75965ae 100644 (file)
--- a/Makefile.in
+++ b/Makefile.in
@@ -422,6 +422,8 @@ $(addprefix $(top_builddir),include include/bits include/sys include/config lib
 $(conf) $(mconf): | $(top_builddir)include/config $(top_builddir)extra/config/lxdialog
        $(Q)$(MAKE) -C extra/config $(@F)
 
+arch-defconfigs := $(notdir $(wildcard $(top_srcdir)extra/Configs/defconfigs/$(ARCH)/*_defconfig))
+
 menuconfig: $(mconf)
        $(Q)$< extra/Configs/Config.in
 
@@ -453,6 +455,9 @@ allnoconfig: $(conf)
 defconfig: $(conf)
        $(Q)$< -D extra/Configs/defconfigs/$(ARCH)/$@ extra/Configs/Config.in
 
+%_defconfig: $(conf)
+       $(Q)$< -D extra/Configs/defconfigs/$(ARCH)/$@ extra/Configs/Config.in
+
 menuconfig-clean-y:
        $(Q)$(MAKE) -C extra/config CLEAN_extra/config