kbuild: use Linux Kernel build scripts

Now we are ready to switch over to real Kbuild.

This commit disables temporary scripts:
  scripts/{Makefile.build.tmp, Makefile.host.tmp}
and enables real Kbuild scripts:
  scripts/{Makefile.build,Makefile.host,Makefile.lib}.

This switch is triggered by the line in scripts/Kbuild.include
  -build := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build.tmp obj
  +build := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build obj

We need to adjust some build scripts for U-Boot.
But smaller amount of modification is preferable.

Additionally, we need to fix compiler flags which are
locally added or removed.

In Kbuild, it is not allowed to change CFLAGS locally.
Instead, ccflags-y, asflags-y, cppflags-y,
CFLAGS_$(basetarget).o, CFLAGS_REMOVE_$(basetarget).o
are prepared for that purpose.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Tested-by: Gerhard Sittig <gsi@denx.de>

2 files changed, 18 insertions, 19 deletions

diff --git a/examples/api/Makefile b/examples/api/Makefile
index db0bb34..8b79886 100644
--- a/examples/api/Makefile
+++ b/examples/api/Makefile
@@ -5,7 +5,7 @@
 #
 
 ifdef FTRACE
-CFLAGS += -finstrument-functions -DFTRACE
+ccflags-y += -finstrument-functions -DFTRACE
 endif
 
 ifeq ($(ARCH),powerpc)
@@ -33,12 +33,6 @@ EXT_COBJ_FILES-y += lib/time.o
 EXT_COBJ_FILES-y += lib/vsprintf.o
 EXT_SOBJ_FILES-$(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))
-SRCS	+= $(addprefix $(SRCTREE)/,$(EXT_SOBJ_FILES-y:.o=.S))
-SRCS	+= $(addprefix $(SRCTREE)/examples/api/,$(COBJ_FILES-y:.o=.c))
-SRCS	+= $(addprefix $(SRCTREE)/examples/api/,$(SOBJ_FILES-y:.o=.S))
-
 # Create a list of object files to be compiled
 OBJS	+= $(addprefix $(obj)/,$(SOBJ_FILES-y))
 OBJS	+= $(addprefix $(obj)/,$(COBJ_FILES-y))
@@ -54,9 +48,10 @@ $(obj)/demo.bin: $(obj)/demo
 		$(OBJCOPY) -O binary $< $@ 2>/dev/null
 
 # Rule to build generic library C files
-$(addprefix $(obj)/,$(notdir $(EXT_COBJ_FILES-y))): $(obj)/%.o: $(SRCTREE)/lib/%.c
-	$(CC) -g $(CFLAGS) -c -o $@ $<
+$(addprefix $(obj)/,$(notdir $(EXT_COBJ_FILES-y))): $(obj)/%.o: $(SRCTREE)/lib/%.c FORCE
+	$(call cmd,force_checksrc)
+	$(call if_changed_rule,cc_o_c)
 
 # Rule to build architecture-specific library assembly files
 $(addprefix $(obj)/,$(notdir $(EXT_SOBJ_FILES-y))): $(obj)/%.o: $(SRCTREE)/arch/$(ARCH)/lib/%.S
-	$(CC) -g $(CFLAGS) -c -o $@ $<
+	$(call if_changed_dep,as_o_S)
diff --git a/examples/standalone/Makefile b/examples/standalone/Makefile
index a6819f7..90e173b 100644
--- a/examples/standalone/Makefile
+++ b/examples/standalone/Makefile
@@ -6,7 +6,7 @@
 #
 
 ifdef FTRACE
-CFLAGS += -finstrument-functions -DFTRACE
+ccflags-y += -finstrument-functions -DFTRACE
 endif
 
 extra-y        := hello_world
@@ -39,10 +39,11 @@ LIBAOBJS := $(LIBAOBJS-y)
 
 LIBCOBJS = stubs.o
 
+.SECONDARY: $(call objectify,$(COBJS))
+targets += $(patsubst $(obj)/%,%,$(LIB)) $(COBJS) $(LIBAOBJS) $(LIBCOBJS)
+
 LIBOBJS	= $(addprefix $(obj)/,$(LIBAOBJS) $(LIBCOBJS))
 
-SRCS	:= $(COBJS:.o=.c) $(LIBCOBJS:.o=.c) $(LIBAOBJS:.o=.S)
-OBJS	:= $(addprefix $(obj)/,$(COBJS))
 ELF	:= $(addprefix $(obj)/,$(ELF))
 
 gcclibdir := $(shell dirname `$(CC) -print-libgcc-file-name`)
@@ -52,19 +53,22 @@ gcclibdir := $(shell dirname `$(CC) -print-libgcc-file-name`)
 # also causes the entry point of the standalone application to be
 # inconsistent.
 ifeq ($(ARCH),powerpc)
-AFLAGS := $(filter-out $(RELFLAGS),$(AFLAGS))
-CFLAGS := $(filter-out $(RELFLAGS),$(CFLAGS))
-CPPFLAGS := $(filter-out $(RELFLAGS),$(CPPFLAGS))
+# FIX ME
+CPPFLAGS := $(filter-out $(RELFLAGS), $(CPPFLAGS))
 endif
 
 # We don't want gcc reordering functions if possible.  This ensures that an
 # application's entry point will be the first function in the application's
 # source file.
-CFLAGS += $(call cc-option,-fno-toplevel-reorder)
+ccflags-y += $(call cc-option,-fno-toplevel-reorder)
 
 #########################################################################
-$(LIB):	$(LIBOBJS)
-	$(call cmd_link_o_target, $(LIBOBJS))
+
+quiet_cmd_link_lib = LD      $@
+      cmd_link_lib = $(LD) $(ld_flags) -r -o $@ $(filter $(LIBOBJS), $^)
+
+$(LIB):	$(LIBOBJS) FORCE
+	$(call if_changed,link_lib)
 
 $(ELF):
 $(obj)/%:	$(obj)/%.o $(LIB)