kbuild: remove obj-dtb-y, pbl-dtb-y, lwl-dtb-y syntax

The embedded DTBs are compiled by the chain of pattern rules as follows:

  %.dts -> %.dtb -> %.dtb.S -> %.dtb.o       for barebox proper
  %.dts -> %.dtb -> %.dtb.S -> %.dtb.pbl.o   for pbl

Barebox introduced {obj,pbl,lwl}-dtb-y syntax to put the intermediate
files into extra-y. The purposes of doing so were:

 [1] prevent GNU Make from deleting the intermediate files
 [2] include .*.cmd files

In contrast, Linux does not use a special syntax for embedding DTBs
into the kernel.

For example, as you see in arch/sh/boot/dts/Makefile of Linux 5.6,

   obj-y += <basename>.dtb.o

... just works.

This is because scripts/Kbuild.include specifies .SECONDARY to cater
to [1], and scripts/Makefile.build adds the intermediates to 'targets'
to deal with [2].

Barebox had already imported the same code from Linux, so you can use
obj-y instead of obj-dtb-y, like Linux.

pbl-dtb-y and lwl-dtb-y are barebox-specific cases, so I added the
%.dtb.pbl.o pattern to intermediate_targets.

Going forward, please use obj-y, pbl-y, or lwl-y.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

2 files changed, 4 insertions, 12 deletions

diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 956df9e23a..f4e7719801 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -304,10 +304,12 @@ intermediate_targets = $(foreach sfx, $(2), \
 					$(filter %$(strip $(1)), $(targets))))
 # %.asn1.o <- %.asn1.[ch] <- %.asn1
 # %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
+# %.dtb.pbl.o <- %.dtb.S <- %.dtb <- %.dts (Barebox only)
 # %.lex.o <- %.lex.c <- %.l
 # %.tab.o <- %.tab.[ch] <- %.y
 targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \
 	   $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
+	   $(call intermediate_targets, .dtb.pbl.o, .dtb.S .dtb) \
 	   $(call intermediate_targets, .lex.o, .lex.c) \
 	   $(call intermediate_targets, .tab.o, .tab.c .tab.h)
 
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 273113ff5a..604bedfc5d 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -20,16 +20,6 @@ obj-m := $(filter-out $(obj-y),$(obj-m))
 
 lib-y := $(filter-out $(obj-y), $(sort $(lib-y) $(lib-m)))
 
-
-pbl-y		+= $(pbl-dtb-y)
-obj-y		+= $(obj-dtb-y)
-extra-y		+= $(patsubst %.dtb.o,%.dtb.S,$(obj-dtb-y))
-extra-y		+= $(patsubst %.dtb.o,%.dtb,$(obj-dtb-y))
-extra-y		+= $(patsubst %.dtb.o,%.dtb.S,$(pbl-dtb-y))
-extra-y		+= $(patsubst %.dtb.o,%.dtb,$(pbl-dtb-y))
-extra-y		+= $(patsubst %.dtb.o,%.dtb.S,$(lwl-dtb-y))
-extra-y		+= $(patsubst %.dtb.o,%.dtb,$(lwl-dtb-y))
-
 # Handle objects in subdirs
 # ---------------------------------------------------------------------------
 # o if we encounter foo/ in $(obj-y), replace it by foo/built-in.o
@@ -40,9 +30,9 @@ extra-y		+= $(patsubst %.dtb.o,%.dtb,$(lwl-dtb-y))
 # lowlevel is present in the PBL if enabled
 # otherwise in barebox
 ifeq ($(CONFIG_PBL_IMAGE), y)
-pbl-y		+= $(lwl-y) $(lwl-dtb-y)
+pbl-y		+= $(lwl-y)
 else
-obj-y		+= $(lwl-y) $(lwl-dtb-y)
+obj-y		+= $(lwl-y)
 endif
 
 obj-y		+= $(obj-pbl-y)