Makefile: descend into subdirectories only when CONFIG_API is defined

All objects under api/ and examples/api/ directories are selected
by CONFIG_API.
So we can move CONFIG_API switch to the top Makefile.

In order to use CONFIG_API, the definition of SUBDIR_EXAMPLES-y
must be moved after "sinlude $(obj)include/autoconf.mk".

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>

Makefile

@@ -136,7 +136,6 @@ unexport CDPATH
 # The "examples" conditionally depend on U-Boot (say, when USE_PRIVATE_LIBGCC
 # is "yes"), so compile examples after U-Boot is compiled.
 SUBDIR_TOOLS = tools
-SUBDIR_EXAMPLES = examples/standalone examples/api
 SUBDIRS = $(SUBDIR_TOOLS)
 
 .PHONY : $(SUBDIRS) $(VERSION_FILE) $(TIMESTAMP_FILE)
@@ -150,8 +149,10 @@ all:
 sinclude $(obj)include/autoconf.mk.dep
 sinclude $(obj)include/autoconf.mk
 
+SUBDIR_EXAMPLES-y := examples/standalone
+SUBDIR_EXAMPLES-$(CONFIG_API) += examples/api
 ifndef CONFIG_SANDBOX
-SUBDIRS += $(SUBDIR_EXAMPLES)
+SUBDIRS += $(SUBDIR_EXAMPLES-y)
 endif
 
 # load ARCH, BOARD, and CPU configuration
@@ -277,7 +278,7 @@ LIBS-y += drivers/usb/phy/
 LIBS-y += drivers/usb/ulpi/
 LIBS-y += common/
 LIBS-y += lib/libfdt/
-LIBS-y += api/
+LIBS-$(CONFIG_API) += api/
 LIBS-y += post/
 LIBS-y += test/
 
@@ -362,7 +363,7 @@ endif
 
 build := -f $(TOPDIR)/scripts/Makefile.build -C
 
-all:		$(ALL-y) $(SUBDIR_EXAMPLES)
+all:		$(ALL-y) $(SUBDIR_EXAMPLES-y)
 
 $(obj)u-boot.dtb:	checkdtc $(obj)u-boot
 		$(MAKE) $(build) dts binary
@@ -550,7 +551,7 @@ $(LIBS):	depend $(SUBDIR_TOOLS)
 $(SUBDIRS):	depend
 		$(MAKE) -C $@ all
 
-$(SUBDIR_EXAMPLES): $(obj)u-boot
+$(SUBDIR_EXAMPLES-y): $(obj)u-boot
 
 $(LDSCRIPT):	depend
 		$(MAKE) -C $(dir $@) $(notdir $@)

api/Makefile

@@ -4,5 +4,6 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
-obj-$(CONFIG_API) += api.o api_display.o api_net.o api_storage.o \
-		       api_platform-$(ARCH).o
+obj-y += api.o api_display.o api_net.o api_storage.o
+obj-$(CONFIG_ARM) += api_platform-arm.o
+obj-$(CONFIG_PPC) += api_platform-powerpc.c

examples/api/Makefile

@@ -14,25 +14,22 @@ endif
 include $(TOPDIR)/config.mk
 
 # Resulting ELF and binary exectuables will be named demo and demo.bin
-OUTPUT-$(CONFIG_API) = $(obj)demo
-OUTPUT = $(OUTPUT-y)
+OUTPUT = $(obj)demo
 
 # Source files located in the examples/api directory
-SOBJ_FILES-$(CONFIG_API) += crt0.o
-COBJ_FILES-$(CONFIG_API) += demo.o
-COBJ_FILES-$(CONFIG_API) += glue.o
-COBJ_FILES-$(CONFIG_API) += libgenwrap.o
+SOBJ_FILES-y += crt0.o
+COBJ_FILES-y += demo.o
+COBJ_FILES-y += glue.o
+COBJ_FILES-y += libgenwrap.o
 
 # Source files which exist outside the examples/api directory
-EXT_COBJ_FILES-$(CONFIG_API) += lib/crc32.o
-EXT_COBJ_FILES-$(CONFIG_API) += lib/ctype.o
-EXT_COBJ_FILES-$(CONFIG_API) += lib/div64.o
-EXT_COBJ_FILES-$(CONFIG_API) += lib/string.o
-EXT_COBJ_FILES-$(CONFIG_API) += lib/time.o
-EXT_COBJ_FILES-$(CONFIG_API) += lib/vsprintf.o
-ifeq ($(ARCH),powerpc)
-EXT_SOBJ_FILES-$(CONFIG_API) += arch/powerpc/lib/ppcstring.o
-endif
+EXT_COBJ_FILES-y += lib/crc32.o
+EXT_COBJ_FILES-y += lib/ctype.o
+EXT_COBJ_FILES-y += lib/div64.o
+EXT_COBJ_FILES-y += lib/string.o
+EXT_COBJ_FILES-y += lib/time.o
+EXT_COBJ_FILES-y += lib/vsprintf.o
+EXT_SOBJ_FILES-$(CONFIG_PPC) += arch/powerpc/lib/ppcstring.o
 
 # Create a list of source files so their dependencies can be auto-generated
 SRCS	+= $(addprefix $(SRCTREE)/,$(EXT_COBJ_FILES-y:.o=.c))