kbuild: consolidate version and timestamp headers generation

- Generate include/generated/{timestamp.h, version.h}
   more simply by using filechk rule.

 - Add $(UBOOTRELEASE) variable and re-write u-boot.imx rule
   more simply.

 - Rename U_BOOT_VERSION in Makefile to UBOOTVERSION

   Before this commit, the same variable name, "U_BOOT_VERSION"
   was used for two different strings.

   One of them was defined in Makefile.
   It takes the form like "2014.01-rc1" and used in
   makefiles and script files.

   The other is defined in include/generated/version.h
   It takes the form like "U-Boot 2014.01-rc1-00010-gbe6d426-dirty"
   and used in C and Aseembler.

   It is confusing when grepping the source tree. So, this commit
   renames the former to UBOOTVERSION.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
diff --git a/Makefile b/Makefile
index d187e6b..7f8d8b5 100644
--- a/Makefile
+++ b/Makefile
@@ -180,9 +180,6 @@
 
 #########################################################################
 
-TIMESTAMP_FILE = include/generated/timestamp_autogenerated.h
-VERSION_FILE = include/generated/version_autogenerated.h
-
 HOSTARCH := $(shell uname -m | \
 	sed -e s/i.86/x86/ \
 	    -e s/sun4u/sparc64/ \
@@ -356,9 +353,11 @@
 		   -fno-builtin -ffreestanding
 KBUILD_AFLAGS   := -D__ASSEMBLY__
 
-U_BOOT_VERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
+# Read UBOOTRELEASE from include/config/uboot.release (if it exists)
+UBOOTRELEASE = $(shell cat include/config/uboot.release 2> /dev/null)
+UBOOTVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
 
-export VERSION PATCHLEVEL SUBLEVEL U_BOOT_VERSION
+export VERSION PATCHLEVEL SUBLEVEL UBOOTRELEASE UBOOTVERSION
 export ARCH CPU BOARD VENDOR SOC
 export CONFIG_SHELL HOSTCC HOSTCFLAGS HOSTLDFLAGS CROSS_COMPILE AS LD CC
 export CPP AR NM LDR STRIP OBJCOPY OBJDUMP
@@ -411,6 +410,9 @@
 # Detect when mixed targets is specified, and make a second invocation
 # of make so .config is not included in this case either (for *config).
 
+version_h := include/generated/version_autogenerated.h
+timestamp_h := include/generated/timestamp_autogenerated.h
+
 no-dot-config-targets := clean clobber mrproper distclean \
 			 help %docs check% coccicheck \
 			 backup
@@ -582,8 +584,6 @@
 cpp_flags := $(KBUILD_CPPFLAGS) $(CPPFLAGS) $(UBOOTINCLUDE) $(NOSTDINC_FLAGS)
 c_flags := $(KBUILD_CFLAGS) $(cpp_flags)
 
-.PHONY : $(VERSION_FILE) $(TIMESTAMP_FILE)
-
 #########################################################################
 # U-Boot objects....order is important (i.e. start must be first)
 
@@ -786,8 +786,7 @@
 		tools/mkimage -A $(ARCH) -T firmware -C none \
 		-O u-boot -a $(CONFIG_SYS_TEXT_BASE) \
 		-e $(CONFIG_SYS_UBOOT_START) \
-		-n $(shell sed -n -e 's/.*U_BOOT_VERSION//p' $(VERSION_FILE) | \
-			sed -e 's/"[	 ]*$$/ for $(BOARD) board"/') \
+		-n "U-Boot $(UBOOTRELEASE) for $(BOARD) board" \
 		-d $< $@
 
 u-boot.imx: u-boot.bin
@@ -943,13 +942,22 @@
 $(u-boot-dirs): depend prepare scripts
 	$(Q)$(MAKE) $(build)=$@
 
-tools: $(TIMESTAMP_FILE) $(VERSION_FILE)
+tools: prepare
 # The "tools" are needed early
 $(filter-out tools, $(u-boot-dirs)): tools
 # The "examples" conditionally depend on U-Boot (say, when USE_PRIVATE_LIBGCC
 # is "yes"), so compile examples after U-Boot is compiled.
 examples: $(filter-out examples, $(u-boot-dirs))
 
+define filechk_uboot.release
+	echo "$(UBOOTVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
+endef
+
+# Store (new) UBOOTRELEASE string in include/config/uboot.release
+include/config/uboot.release: Makefile FORCE
+	$(call filechk,uboot.release)
+
+
 # Things we need to do before we recursively start building the kernel
 # or the modules are listed in "prepare".
 # A multi level approach is used. prepareN is processed before prepareN-1.
@@ -962,7 +970,7 @@
 # prepare3 is used to check if we are building in a separate output directory,
 # and if so do:
 # 1) Check that make has not been executed in the kernel src $(srctree)
-prepare3:
+prepare3: include/config/uboot.release
 ifneq ($(KBUILD_SRC),)
 	@$(kecho) '  Using $(srctree) as source for u-boot'
 	$(Q)if [ -f $(srctree)/include/config.mk ]; then \
@@ -975,7 +983,7 @@
 # prepare2 creates a makefile if using a separate output directory
 prepare2: prepare3 outputmakefile
 
-prepare1: prepare2
+prepare1: prepare2 $(version_h) $(timestamp_h)
 	@:
 
 archprepare: prepare1 scripts_basic
@@ -986,6 +994,27 @@
 # All the preparing..
 prepare: prepare0
 
+# Generate some files
+# ---------------------------------------------------------------------------
+
+define filechk_version.h
+	(echo \#define PLAIN_VERSION \"$(UBOOTRELEASE)\"; \
+	echo \#define U_BOOT_VERSION \"U-Boot \" PLAIN_VERSION; \
+	echo \#define CC_VERSION_STRING \"$$($(CC) --version | head -n 1)\"; \
+	echo \#define LD_VERSION_STRING \"$$($(LD) --version | head -n 1)\"; )
+endef
+
+define filechk_timestamp.h
+	(LC_ALL=C date +'#define U_BOOT_DATE "%b %d %C%y"'; \
+	LC_ALL=C date +'#define U_BOOT_TIME "%T"')
+endef
+
+$(version_h): $(srctree)/Makefile FORCE
+	$(call filechk,version.h)
+
+$(timestamp_h): $(srctree)/Makefile FORCE
+	$(call filechk,timestamp.h)
+
 #
 # Auto-generate the autoconf.mk file (which is included by all makefiles)
 #
@@ -1009,16 +1038,16 @@
 include/autoconf.mk: include/config.h
 	$(call cmd,autoconf)
 
-u-boot.lds: $(LDSCRIPT) depend
+u-boot.lds: $(LDSCRIPT) depend prepare
 		$(CPP) $(cpp_flags) $(LDPPFLAGS) -ansi -D__ASSEMBLY__ -P - <$< >$@
 
-nand_spl:	$(TIMESTAMP_FILE) $(VERSION_FILE) depend prepare
+nand_spl: depend prepare
 		$(MAKE) $(build)=nand_spl/board/$(BOARDDIR) all
 
 u-boot-nand.bin:	nand_spl u-boot.bin
 		cat nand_spl/u-boot-spl-16k.bin u-boot.bin > u-boot-nand.bin
 
-spl/u-boot-spl.bin: tools depend prepare 
+spl/u-boot-spl.bin: tools depend prepare
 		$(MAKE) obj=spl -f $(srctree)/spl/Makefile all
 
 tpl/u-boot-tpl.bin: tools depend prepare
@@ -1026,7 +1055,7 @@
 
 # Explicitly make _depend in subdirs containing multiple targets to prevent
 # parallel sub-makes creating .depend files simultaneously.
-depend dep:	$(TIMESTAMP_FILE) $(VERSION_FILE) \
+depend dep:	\
 		include/generated/generic-asm-offsets.h \
 		include/generated/asm-offsets.h
 
@@ -1127,27 +1156,7 @@
 		false; \
 	fi
 
-$(VERSION_FILE):
-		@mkdir -p $(dir $(VERSION_FILE))
-		@( localvers='$(shell $(TOPDIR)/scripts/setlocalversion $(TOPDIR))' ; \
-		   printf '#define PLAIN_VERSION "%s%s"\n' \
-			"$(U_BOOT_VERSION)" "$${localvers}" ; \
-		   printf '#define U_BOOT_VERSION "U-Boot %s%s"\n' \
-			"$(U_BOOT_VERSION)" "$${localvers}" ; \
-		) > $@.tmp
-		@( printf '#define CC_VERSION_STRING "%s"\n' \
-		 '$(shell $(CC) --version | head -n 1)' )>>  $@.tmp
-		@( printf '#define LD_VERSION_STRING "%s"\n' \
-		 '$(shell $(LD) -v | head -n 1)' )>>  $@.tmp
-		@cmp -s $@ $@.tmp && rm -f $@.tmp || mv -f $@.tmp $@
-
-$(TIMESTAMP_FILE):
-		@mkdir -p $(dir $(TIMESTAMP_FILE))
-		@LC_ALL=C date +'#define U_BOOT_DATE "%b %d %C%y"' > $@.tmp
-		@LC_ALL=C date +'#define U_BOOT_TIME "%T"' >> $@.tmp
-		@cmp -s $@ $@.tmp && rm -f $@.tmp || mv -f $@.tmp $@
-
-env: depend scripts_basic
+env: scripts_basic
 	$(Q)$(MAKE) $(build)=tools/$@
 
 tools-all: HOST_TOOLS_ALL=y