kbuild: create a list of all built DTB files

It is useful to have a list of all *.dtb and *.dtbo files generated
from the current build.

With this commit, 'make dtbs' creates arch/*/boot/dts/dtbs-list, which
lists the dtb(o) files created in the current build. It maintains the
order of the dtb-y additions in Makefiles although the order is not
important for DTBs. It is a (good) side effect through the reuse of the
modules.order rule.

Please note this list only includes the files directly added to dtb-y.

For example, consider this case:

    foo-dtbs := foo_base.dtb foo_overlay.dtbo
    dtb-y := foo.dtb

In this example, the list will include foo.dtb, but not foo_base.dtb
or foo_overlay.dtbo.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index cd5b181060f1..b35d39022a30 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -45,6 +45,11 @@ else
 obj-y		:= $(filter-out %/, $(obj-y))
 endif
 
+ifdef need-dtbslist
+dtb-y		+= $(addsuffix /dtbs-list, $(subdir-ym))
+always-y	+= dtbs-list
+endif
+
 # Expand $(foo-objs) $(foo-y) etc. by replacing their individuals
 suffix-search = $(strip $(foreach s, $3, $($(1:%$(strip $2)=%$s))))
 # List composite targets that are constructed by combining other targets
@@ -99,6 +104,7 @@ lib-y		:= $(addprefix $(obj)/,$(lib-y))
 real-obj-y	:= $(addprefix $(obj)/,$(real-obj-y))
 real-obj-m	:= $(addprefix $(obj)/,$(real-obj-m))
 multi-obj-m	:= $(addprefix $(obj)/, $(multi-obj-m))
+dtb-y		:= $(addprefix $(obj)/, $(dtb-y))
 multi-dtb-y	:= $(addprefix $(obj)/, $(multi-dtb-y))
 real-dtb-y	:= $(addprefix $(obj)/, $(real-dtb-y))
 subdir-ym	:= $(addprefix $(obj)/,$(subdir-ym))