The attached patch implements dependency tracking for coreboot.

Obviously compile time increases slightly because more work has to be done, but
I'm sure the benefit of having to rm -rf build less often is worth it :-)

Other small changes:
* be a bit more verbose on some of the created files
* move -O2 from compiler rule into bootblock_romccflags
* drop rule needed for util/*.c -> build/*.o as x86emu no longer lives in util.

Signed-off-by: Stefan Reinauer <stepan@coresystems.de>

Index: src/lib/Makefile.inc
===================================================================
--- src/lib/Makefile.inc	(revision 5279)
+++ src/lib/Makefile.inc	(working copy)
@@ -28,8 +28,4 @@
 
 obj-$(CONFIG_BOOTSPLASH) += jpeg.o
 
-ifdef POST_EVALUATION
-$(obj)/lib/version.o :: $(obj)/build.h
-endif
-
 smmobj-y += memcpy.o
Index: src/arch/i386/Makefile.bootblock.inc
===================================================================
--- src/arch/i386/Makefile.bootblock.inc	(revision 5279)
+++ src/arch/i386/Makefile.bootblock.inc	(working copy)
@@ -44,27 +44,34 @@
 bootblock_inc += $(obj)/mainboard/$(MAINBOARDDIR)/bootblock.inc
 bootblock_inc += $(src)/arch/i386/lib/walkcbfs.S
 
-bootblock_romccflags := -mcpu=i386
+bootblock_romccflags := -mcpu=i386 -O2
 ifeq ($(CONFIG_SSE),y)
-bootblock_romccflags := -mcpu=k7 -msse
+bootblock_romccflags := -mcpu=k7 -msse -O2
 endif
 
 $(obj)/bootblock/ldscript.ld: $(bootblock_ldscripts) $(obj)/ldoptions
+	@printf "    GEN        $(subst $(obj)/,,$(@))\n"
 	mkdir -p $(obj)/bootblock
 	printf '$(foreach ldscript,ldoptions $(bootblock_lds),INCLUDE "$(ldscript)"\n)' > $@
 
 $(obj)/bootblock/bootblock.c: $(bootblock_inc)
+	@printf "    GEN        $(subst $(obj)/,,$(@))\n"
 	mkdir -p $(obj)/bootblock
 	printf '$(foreach crt0,config.h $(bootblock_inc),#include "$(crt0)"\n)' > $@
 
 $(obj)/mainboard/$(MAINBOARDDIR)/bootblock.o: $(obj)/mainboard/$(MAINBOARDDIR)/bootblock.s
+	@printf "    CC         $(subst $(obj)/,,$(@))\n"
 	$(CC) -I$(obj) -Wa,-acdlns -c -o $@ $<  > $(dir $@)/crt0.disasm
 
 $(obj)/mainboard/$(MAINBOARDDIR)/bootblock.s: $(obj)/bootblock/bootblock.c
+	@printf "    CC         $(subst $(obj)/,,$(@))\n"
 	$(CC) -x assembler-with-cpp -DASSEMBLY -E -I$(src)/include -I$(src)/arch/i386/include -I$(obj) -I$(obj)/bootblock -include $(obj)/config.h -I. -I$(src) $< > $@.new && mv $@.new $@
 
 $(obj)/mainboard/$(MAINBOARDDIR)/bootblock.inc: $(src)/arch/i386/init/$(subst ",,$(CONFIG_BOOTBLOCK_SOURCE)) $(obj)/romcc
-	$(obj)/romcc $(bootblock_romccflags) -O2 $(ROMCCFLAGS) $(INCLUDES) $< -o $@
+	@printf "    ROMCC      $(subst $(obj)/,,$(@)) $(<)\n"
+	$(CC) -MM -MT$(obj)/mainboard/$(MAINBOARDDIR)/bootblock.inc \
+		$< > $(obj)/mainboard/$(MAINBOARDDIR)/bootblock.inc.d
+	$(obj)/romcc $(bootblock_romccflags) $(ROMCCFLAGS) $(INCLUDES) $< -o $@
 
 $(obj)/bootblock.elf: $(obj)/mainboard/$(MAINBOARDDIR)/bootblock.o $(obj)/bootblock/ldscript.ld
 	@printf "    LINK       $(subst $(obj)/,,$(@))\n"
@@ -87,6 +94,7 @@
 	$(OBJCOPY) -O binary $(obj)/romstage.elf $@
 
 $(obj)/romstage/ldscript.ld: $(ldscripts) $(obj)/ldoptions
+	@printf "    GEN        $(subst $(obj)/,,$(@))\n"
 	mkdir -p $(obj)/romstage
 	printf '$(foreach ldscript,ldoptions location.ld $(ldscripts),INCLUDE "$(ldscript:$(obj)/%=%)"\n)' > $@
 
@@ -96,9 +104,11 @@
 	printf '$(foreach crt0,config.h $(crt0s),#include "$(crt0:$(obj)/%=%)"\n)' > $@
 
 $(obj)/mainboard/$(MAINBOARDDIR)/crt0.initobj.o: $(obj)/mainboard/$(MAINBOARDDIR)/crt0.s
+	@printf "    CC         $(subst $(obj)/,,$(@))\n"
 	$(CC) -I$(obj) -Wa,-acdlns -c -o $@ $<  > $(dir $@)/crt0.disasm
 
 $(obj)/mainboard/$(MAINBOARDDIR)/crt0.s: $(src)/arch/i386/init/crt0.S.lb $(obj)/romstage/crt0_includes.h
+	@printf "    CC         $(subst $(obj)/,,$(@))\n"
 	$(CC) -x assembler-with-cpp -DASSEMBLY -E -I$(src)/include -I$(src)/arch/i386/include -I$(obj) -I$(obj)/romstage -include $(obj)/config.h -I. -I$(src) $< > $@.new && mv $@.new $@
 
 endif
Index: src/arch/i386/Makefile.bigbootblock.inc
===================================================================
--- src/arch/i386/Makefile.bigbootblock.inc	(revision 5279)
+++ src/arch/i386/Makefile.bigbootblock.inc	(working copy)
@@ -23,10 +23,12 @@
 	printf '$(foreach crt0,config.h $(crt0s),#include "$(crt0:$(obj)/%=%)"\n)' > $@
 
 $(obj)/mainboard/$(MAINBOARDDIR)/crt0.initobj.o: $(obj)/mainboard/$(MAINBOARDDIR)/crt0.s
-	$(CC) -I$(obj) -Wa,-acdlns -c -o $@ $<  > $(dir $@)/crt0.disasm
+	@printf "    CC         $(subst $(obj)/,,$(@))\n"
+	$(CC) -MMD -I$(obj) -Wa,-acdlns -c -o $@ $<  > $(dir $@)/crt0.disasm
 
 $(obj)/mainboard/$(MAINBOARDDIR)/crt0.s: $(src)/arch/i386/init/crt0.S.lb $(obj)/crt0_includes.h
-	$(CC) -x assembler-with-cpp -DASSEMBLY -E -I$(src)/include -I$(src)/arch/i386/include -I$(obj) -include $(obj)/config.h -I. -I$(src) $< > $@.new && mv $@.new $@
+	@printf "    CC         $(subst $(obj)/,,$(@))\n"
+	$(CC) -MMD -x assembler-with-cpp -DASSEMBLY -E -I$(src)/include -I$(src)/arch/i386/include -I$(obj) -include $(obj)/config.h -I. -I$(src) $< > $@.new && mv $@.new $@
 
 $(obj)/coreboot: $(initobjs) $(obj)/ldscript.ld
 	@printf "    LINK       $(subst $(obj)/,,$(@))\n"
Index: src/arch/i386/Makefile.inc
===================================================================
--- src/arch/i386/Makefile.inc	(revision 5279)
+++ src/arch/i386/Makefile.inc	(working copy)
@@ -25,6 +25,7 @@
 COREBOOT_ROM_DEPENDENCIES+=$(CONFIG_FALLBACK_BOOTSPLASH_FILE)
 endif
 $(obj)/coreboot.rom: $(obj)/coreboot.pre $(obj)/coreboot_ram $(CBFSTOOL) $(call strip_quotes,$(COREBOOT_ROM_DEPENDENCIES))
+	printf "    CBFS       $(subst $(obj)/,,$(@))\n"
 	cp $(obj)/coreboot.pre $@.tmp
 	if [ -f fallback/coreboot_apc ]; \
 	then \
@@ -199,15 +200,17 @@
 else
 
 $(obj)/mainboard/$(MAINBOARDDIR)/ap_romstage.o: $(src)/mainboard/$(MAINBOARDDIR)/ap_romstage.c $(obj)/option_table.h
-	$(CC) $(CFLAGS) -I$(src) -I. -c -S  $(src)/mainboard/$(MAINBOARDDIR)/ap_romstage.c -o $@
+	@printf "    CC         $(subst $(obj)/,,$(@))\n"
+	$(CC) -MMD $(CFLAGS) -I$(src) -I. -c -S  $(src)/mainboard/$(MAINBOARDDIR)/ap_romstage.c -o $@
 
-$(obj)/mainboard/$(MAINBOARDDIR)/romstage.inc: $(src)/mainboard/$(MAINBOARDDIR)/romstage.c $(OPTION_TABLE_H) $(obj)/build.h
+$(obj)/mainboard/$(MAINBOARDDIR)/romstage.pre.inc: $(src)/mainboard/$(MAINBOARDDIR)/romstage.c $(OPTION_TABLE_H) $(obj)/build.h
 	printf "    CC         romstage.inc\n"
-	$(CC) $(CFLAGS) -include $(obj)/build.h -I$(src) -I. -c -S $< -o $@.tmp1
+	$(CC) -MMD $(CFLAGS) -include $(obj)/build.h -I$(src) -I. -c -S $< -o $@
+
+$(obj)/mainboard/$(MAINBOARDDIR)/romstage.inc: $(obj)/mainboard/$(MAINBOARDDIR)/romstage.pre.inc
 	printf "    POST       romstage.inc\n"
-	sed -e 's/\.rodata/.rom.data/g' -e 's/\.text/.section .rom.text/g' $@.tmp1 > $@.tmp
+	sed -e 's/\.rodata/.rom.data/g' -e 's/\.text/.section .rom.text/g' $^ > $@.tmp
 	mv $@.tmp $@
-	rm -f $@.tmp1
 endif
 
 else
Index: Makefile
===================================================================
--- Makefile	(revision 5279)
+++ Makefile	(working copy)
@@ -216,11 +216,7 @@
 de$(EMPTY)fine $(1)_$(2)_template
 $(obj)/$$(1)%$(3).o: src/$$(1)%.$(2) $(obj)/config.h
 	printf "    CC         $$$$(subst $$$$(obj)/,,$$$$(@))\n"
-	$(CC) $(4) $$$$(CFLAGS) -c -o $$$$@ $$$$<
-
-$(obj)/$$(1)%$(3).o: obj/$$(1)%.$(2) $(obj)/config.h
-	printf "    CC         $$$$(subst $$$$(obj)/,,$$$$(@))\n"
-	$(CC) $(4) $$$$(CFLAGS) -c -o $$$$@ $$$$<
+	$(CC) $(4) -MMD $$$$(CFLAGS) -c -o $$$$@ $$$$<
 en$(EMPTY)def
 endef
 
@@ -245,6 +241,9 @@
 $(eval $(call usetemplate,smmobjs,c))
 $(eval $(call usetemplate,smmobjs,S))
 
+DEPENDENCIES = $(objs:.o=.d) $(initobjs:.o=.d) $(drivers:.o=.d) $(smmobjs:.o=.d)
+-include $(DEPENDENCIES)
+
 printall:
 	@echo objs:=$(objs)
 	@echo initobjs:=$(initobjs)
@@ -252,6 +251,7 @@
 	@echo smmobjs:=$(smmobjs)
 	@echo alldirs:=$(alldirs)
 	@echo allsrc=$(allsrc)
+	@echo DEPENDENCIES=$(DEPENDENCIES)
 	@echo LIBGCC_FILE_NAME=$(LIBGCC_FILE_NAME)
 
 printcrt0s:
@@ -316,12 +316,13 @@
 
 clean-for-update: doxygen-clean
 	rm -f $(objs) $(initobjs) $(drivers) $(smmobjs) .xcompile
+	rm -f $(DEPENDENCIES)
 	rm -f $(obj)/coreboot_ram* $(obj)/coreboot.romstage $(obj)/coreboot.pre* $(obj)/coreboot.bootblock $(obj)/coreboot.a
 	rm -rf $(obj)/bootblock* $(obj)/romstage* $(obj)/location.*
 	rm -f $(obj)/option_table.* $(obj)/crt0_includes.h $(obj)/ldscript
 	rm -f $(obj)/mainboard/$(MAINBOARDDIR)/static.c $(obj)/mainboard/$(MAINBOARDDIR)/config.py $(obj)/mainboard/$(MAINBOARDDIR)/static.dot
 	rm -f $(obj)/mainboard/$(MAINBOARDDIR)/crt0.s $(obj)/mainboard/$(MAINBOARDDIR)/crt0.disasm
-	rm -f $(obj)/mainboard/$(MAINBOARDDIR)/failover.inc $(obj)/mainboard/$(MAINBOARDDIR)/romstage.inc 
+	rm -f $(obj)/mainboard/$(MAINBOARDDIR)/romstage.inc 
 	rm -f $(obj)/mainboard/$(MAINBOARDDIR)/bootblock.* $(obj)/mainboard/$(MAINBOARDDIR)/dsdt.*
 	rm -f $(obj)/cpu/x86/smm/smm_bin.c $(obj)/cpu/x86/smm/smm.* $(obj)/cpu/x86/smm/smm
 	rmdir -p $(alldirs) 2>/dev/null >/dev/null || true