kbuild: support building signle targets

Import build rules of single targets from Linux 3.13.

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

Makefile

@@ -1267,6 +1267,58 @@ scripts: ;
 endif #ifeq ($(config-targets),1)
 endif #ifeq ($(mixed-targets),1)
 
+# Single targets
+# ---------------------------------------------------------------------------
+# Single targets are compatible with:
+# - build with mixed source and output
+# - build with separate output dir 'make O=...'
+# - external modules
+#
+#  target-dir => where to store outputfile
+#  build-dir  => directory in kernel source tree to use
+
+ifeq ($(KBUILD_EXTMOD),)
+        build-dir  = $(patsubst %/,%,$(dir $@))
+        target-dir = $(dir $@)
+else
+        zap-slash=$(filter-out .,$(patsubst %/,%,$(dir $@)))
+        build-dir  = $(KBUILD_EXTMOD)$(if $(zap-slash),/$(zap-slash))
+        target-dir = $(if $(KBUILD_EXTMOD),$(dir $<),$(dir $@))
+endif
+
+%.s: %.c prepare scripts FORCE
+	$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
+%.i: %.c prepare scripts FORCE
+	$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
+%.o: %.c prepare scripts FORCE
+	$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
+%.lst: %.c prepare scripts FORCE
+	$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
+%.s: %.S prepare scripts FORCE
+	$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
+%.o: %.S prepare scripts FORCE
+	$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
+%.symtypes: %.c prepare scripts FORCE
+	$(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
+
+# Modules
+/: prepare scripts FORCE
+	$(cmd_crmodverdir)
+	$(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
+	$(build)=$(build-dir)
+%/: prepare scripts FORCE
+	$(cmd_crmodverdir)
+	$(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
+	$(build)=$(build-dir)
+%.ko: prepare scripts FORCE
+	$(cmd_crmodverdir)
+	$(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1)   \
+	$(build)=$(build-dir) $(@:.ko=.o)
+	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
+
+# FIXME Should go into a make.lib or something 
+# ===========================================================================
+
 quiet_cmd_rmdirs = $(if $(wildcard $(rm-dirs)),CLEAN   $(wildcard $(rm-dirs)))
       cmd_rmdirs = rm -rf $(rm-dirs)