Makefile.inc: Add x86 bootblock as a separate target

Some platforms don't need a top aligned bootblock in cbfs like Intel
APL or modern AMD platforms as the bootblock is loaded differently.
So they don't need the top aligned cbfs bootblock.

To not clutter the main make file move out adding the bootblock.

Change-Id: I4de9d7fedf1ae5a37a3310dd42eb07b44c030930
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/56122
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Raul Rangel <rrangel@chromium.org>

Makefile.inc

@@ -1105,18 +1105,8 @@ endif
 $(shell rm -f $(obj)/coreboot.pre)
 
 ifneq ($(CONFIG_UPDATE_IMAGE),y)
-$(obj)/coreboot.pre: $(objcbfs)/bootblock.bin $$(prebuilt-files) $(CBFSTOOL) $(obj)/fmap.fmap $(obj)/fmap.desc
+$(obj)/coreboot.pre: $$(prebuilt-files) $(CBFSTOOL) $(obj)/fmap.fmap $(obj)/fmap.desc
 	$(CBFSTOOL) $@.tmp create -M $(obj)/fmap.fmap -r $(shell cat $(obj)/fmap.desc)
-ifeq ($(CONFIG_ARCH_X86),y)
-	$(CBFSTOOL) $@.tmp add \
-		-f $(objcbfs)/bootblock.bin \
-		-n bootblock \
-		-t bootblock \
-		$(TXTIBB) \
-		-b -$(call file-size,$(objcbfs)/bootblock.bin) $(cbfs-autogen-attributes) \
-		$(TS_OPTIONS) \
-		$(CBFSTOOL_ADD_CMD_OPTIONS)
-endif # ifeq ($(CONFIG_ARCH_X86),y)
 	$(prebuild-files) true
 	mv $@.tmp $@
 else # ifneq ($(CONFIG_UPDATE_IMAGE),y)

src/arch/x86/Makefile.inc

@@ -100,6 +100,13 @@ else
 $(eval $(call early_x86_stage,bootblock,elf64-x86-64))
 endif
 
+ifneq ($(CONFIG_UPDATE_IMAGE),y)
+$(call add_intermediate, add_bootblock, $(objcbfs)/bootblock.bin)
+	@printf "    CBFS       $(subst $(obj)/,,$(@))\n"
+	$(CBFSTOOL) $< add -f $(objcbfs)/bootblock.bin  -n bootblock -t bootblock $(TXTIBB) -b -$(call file-size,$(objcbfs)/bootblock.bin) \
+	$(cbfs-autogen-attributes) $(TS_OPTIONS) $(CBFSTOOL_ADD_CMD_OPTIONS)
+endif
+
 $(call src-to-obj,bootblock,$(dir)/walkcbfs.S): $(obj)/fmap_config.h
 bootblock-y += walkcbfs.S