On 11/6/25 22:08, Marek Vasut wrote:
In case DEVICE_TREE_DEBUG is set, produce a diff between the base DT and
DT with U-Boot extras, to show how much does the U-Boot DT differ from
the base DT. This is particularly useful together with OF_UPSTREAM, to
minimize the diff between upstream DTs and U-Boot DTs.
Example usage:
$ make r8a779g3_sparrowhawk_defconfig && make DEVICE_TREE_DEBUG=1
$ cat ./dts/upstream/src/arm64/renesas/r8a779g3-sparrow-hawk.dtb.diff
This still has a downside. Even 'dtc -I dts -O dts ...' applied on
base DT and U-Boot augmented DT can produce different phandle IDs
for the same node in those two DTs, which results in a lot of noise
in the resulting diff. The only way I can think of is to patch DTC
to emit full paths in those phandles instead, something like a
phandle = <&{/full/path/to/remote/end} ...>;
Signed-off-by: Marek Vasut <[email protected]>
---
Cc: Adriano Cordova <[email protected]>
Cc: Heinrich Schuchardt <[email protected]>
Cc: Ilias Apalodimas <[email protected]>
Cc: Peter Robinson <[email protected]>
Cc: Sam Edwards <[email protected]>
Cc: Tom Rini <[email protected]>
Cc: [email protected]
Hello Marek,
Without documentation developers will not know about the new feature.
Could you, please, add a doc/build/ change in the next iteration.
Tested-by: Heinrich Schuchardt <[email protected]>
---
scripts/Makefile.lib | 24 +++++++++++++++++++++++-
1 file changed, 23 insertions(+), 1 deletion(-)
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 5db2fbc418a..2d8bf3c04f4 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -386,10 +386,31 @@ ifeq ($(CONFIG_OF_LIBFDT_OVERLAY),y)
DTC_FLAGS += -@
endif
+# In case DEVICE_TREE_DEBUG is set, produce a diff between the base DT and
+# DT with U-Boot extras, to show how much does the U-Boot DT differ from
+# the base DT. This is particularly useful together with OF_UPSTREAM, to
+# minimize the diff between upstream DTs and U-Boot DTs.
+ifdef DEVICE_TREE_DEBUG
+cmd_dtc_diff = \
+ $(HOSTCC) -E $(dtc_cpp_flags) -I$(obj) -x assembler-with-cpp -o $(dtn-tmp)
$< ; \
+ $(DTC) -s -O dts -o [email protected] -b 0 \
+ -i $(dir $<) $(DTC_FLAGS) $(dtn-tmp) || \
+ (echo "Check $(shell pwd)/$< for errors" && false); \
+ $(DTC) -s -O dts -o [email protected] -b 0 \
+ -i $(dir $<) -i $(u_boot_dtsi_loc) $(DTC_FLAGS) $(dtc-tmp) || \
+ (echo "Check $(shell pwd)/$(pre-tmp) for errors" && false); \
+ (diff -Naru [email protected] [email protected] > [email protected] || true)
+
+dtn-tmp = $(subst $(comma),_,$(dot-target).dtn.tmp)
+else
+cmd_dtc_diff =
+endif
+
quiet_cmd_dtc = DTC $@
# Modified for U-Boot
# Bring in any U-Boot-specific include at the end of the file
# And finally any custom .dtsi fragments specified with
CONFIG_DEVICE_TREE_INCLUDES
+
cmd_dtc = mkdir -p $(dir ${dtc-tmp}) ; \
(cat $< > $(pre-tmp)); \
$(foreach f,$(subst $(quote),,$(dtsi_include_list)
$(CONFIG_DEVICE_TREE_INCLUDES)), \
@@ -400,7 +421,8 @@ cmd_dtc = mkdir -p $(dir ${dtc-tmp}) ; \
-d $(depfile).dtc.tmp $(dtc-tmp) || \
(echo "Check $(shell pwd)/$(pre-tmp) for errors" && false) \
; \
- sed "s:$(pre-tmp):$(<):" $(depfile).pre.tmp $(depfile).dtc.tmp >
$(depfile)
+ sed "s:$(pre-tmp):$(<):" $(depfile).pre.tmp $(depfile).dtc.tmp >
$(depfile) ; \
+ $(cmd_dtc_diff)
dtsi_include_list_deps := $(addprefix $(u_boot_dtsi_loc),$(subst $(quote),,$(dtsi_include_list)))
