This piece of code converts the target suffix to the dtc -O option:
*.dtb -> -O dtb
*.dt.yaml -> -O yaml
Commit ce88c9c79455 ("kbuild: Add support to build overlays (%.dtbo)")
added the third case:
*.dtbo -> -O dtbo
This works thanks to commit 163f0469bf2e ("dtc: Allow overlays to have
.dtbo extension") in the upstream DTC, which has already been pulled in
the kernel.
However, I think it is a bit odd because "dtbo" is not a format name.
At least, it does not show up in the help message of dtc.
$ scripts/dtc/dtc --help
[ snip ]
-O, --out-format <arg>
Output formats are:
dts - device tree source text
dtb - device tree blob
yaml - device tree encoded as YAML
asm - assembler source
So, I am not a big fan of the second hunk of that change:
} else if (streq(outform, "dtbo")) {
dt_to_blob(outf, dti, outversion);
Anyway, we did not need to do this in Makefile in the first place.
guess_type_by_name() had already understood ".yaml" before commit
4f0e3a57d6eb ("kbuild: Add support for DT binding schema checks"),
and now does ".dtbo" as well.
Makefile does not need to duplicate the same logic. Let's leave it
to dtc.
Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
---
scripts/Makefile.lib | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index eee59184de64..90a4e04cd8f5 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -327,7 +327,7 @@ $(obj)/%.dtb.S: $(obj)/%.dtb FORCE
quiet_cmd_dtc = DTC $@
cmd_dtc = $(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
- $(DTC) -O $(patsubst .%,%,$(suffix $@)) -o $@ -b 0 \
+ $(DTC) -o $@ -b 0 \
$(addprefix -i,$(dir $<) $(DTC_INCLUDE)) $(DTC_FLAGS) \
-d $(depfile).dtc.tmp $(dtc-tmp) ; \
cat $(depfile).pre.tmp $(depfile).dtc.tmp > $(depfile)
--
2.27.0
