Commit ef8795f3 authored by Rob Herring's avatar Rob Herring
Browse files

dt-bindings: kbuild: Use DTB files for validation 



Switch the DT validation to use DTB files directly instead of a DTS to
YAML conversion.

The original motivation for supporting validation on DTB files was to
enable running validation on a running system (e.g. 'dt-validate
/sys/firmware/fdt') or other cases where the original source DTS is not
available.

The YAML format was not without issues. Using DTBs with the schema type
information solves some of those problems. The YAML format relies on the
DTS source level information including bracketing of properties, size
directives, and phandle tags all of which are lost in a DTB file. While
standardizing the bracketing is a good thing, it does cause a lot of
extra warnings and churn to fix them.

Another issue has been signed types are not validated correctly as sign
information is not propagated to YAML. Using the schema type information
allows for proper handling of signed types. YAML also can't represent
the full range of 64-bit integers as numbers are stored as floats by
most/all parsers.

The DTB validation works by decoding property values using the type
information in the schemas themselves. The main corner case this does
not work for is matrix types where neither dimension is fixed. For
now, checking the dimensions in these cases are skipped.

Signed-off-by: default avatarRob Herring <robh@kernel.org>
Tested-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20220310160513.1708182-3-robh@kernel.org
parent 2783a7f5

Documentation/devicetree/bindings/Makefile

+3 −4
Original line number Diff line number Diff line
@@ -26,8 +26,7 @@ $(obj)/%.example.dts: $(src)/%.yaml check_dtschema_version FORCE 
	$(call if_changed,extract_ex)



find_all_cmd = find $(srctree)/$(src) \( -name '*.yaml' ! \

		-name 'processed-schema*' ! \

		-name '*.example.dt.yaml' \)

		-name 'processed-schema*' \)



find_cmd = $(find_all_cmd) | grep -F "$(DT_SCHEMA_FILES)"

CHK_DT_DOCS := $(shell $(find_cmd))
@@ -72,9 +71,9 @@ $(obj)/processed-schema.json: $(DT_DOCS) $(src)/.yamllint check_dtschema_version 


always-y += processed-schema.json

always-$(CHECK_DT_BINDING) += $(patsubst $(srctree)/$(src)/%.yaml,%.example.dts, $(CHK_DT_DOCS))

always-$(CHECK_DT_BINDING) += $(patsubst $(srctree)/$(src)/%.yaml,%.example.dt.yaml, $(CHK_DT_DOCS))

always-$(CHECK_DT_BINDING) += $(patsubst $(srctree)/$(src)/%.yaml,%.example.dtb, $(CHK_DT_DOCS))



# Hack: avoid 'Argument list too long' error for 'make clean'. Remove most of

# build artifacts here before they are processed by scripts/Makefile.clean

clean-files = $(shell find $(obj) \( -name '*.example.dts' -o \

			-name '*.example.dt.yaml' \) -delete 2>/dev/null)
 
			-name '*.example.dtb' \) -delete 2>/dev/null)

Documentation/devicetree/bindings/writing-schema.rst

+5 −12
Original line number Diff line number Diff line
@@ -120,20 +120,13 @@ project can be installed with pip:: 


    pip3 install dtschema



Several executables (dt-doc-validate, dt-mk-schema, dt-validate) will be

installed. Ensure they are in your PATH (~/.local/bin by default).



dtc must also be built with YAML output support enabled. This requires that

libyaml and its headers be installed on the host system. For some distributions

that involves installing the development package, such as:



Debian::

Note that 'dtschema' installation requires 'swig' and Python development files

installed first. On Debian/Ubuntu systems::



  apt-get install libyaml-dev

    apt install swig python3-dev



Fedora::



  dnf -y install libyaml-devel

Several executables (dt-doc-validate, dt-mk-schema, dt-validate) will be

installed. Ensure they are in your PATH (~/.local/bin by default).



Running checks

~~~~~~~~~~~~~~

scripts/Makefile.lib

+7 −13
Original line number Diff line number Diff line
@@ -87,11 +87,6 @@ base-dtb-y := $(foreach m, $(multi-dtb-y), $(firstword $(call suffix-search, $m, 


always-y			+= $(dtb-y)



ifneq ($(CHECK_DTBS),)

always-y += $(patsubst %.dtb,%.dt.yaml, $(real-dtb-y))

always-y += $(patsubst %.dtbo,%.dt.yaml, $(real-dtb-y))

endif



# Add subdir path



extra-y		:= $(addprefix $(obj)/,$(extra-y))
@@ -347,12 +342,6 @@ cmd_dtc = $(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; 
		-d $(depfile).dtc.tmp $(dtc-tmp) ; \

	cat $(depfile).pre.tmp $(depfile).dtc.tmp > $(depfile)



$(obj)/%.dtb: $(src)/%.dts $(DTC) FORCE

	$(call if_changed_dep,dtc)



$(obj)/%.dtbo: $(src)/%.dts $(DTC) FORCE

	$(call if_changed_dep,dtc)



quiet_cmd_fdtoverlay = DTOVL   $@

      cmd_fdtoverlay = $(objtree)/scripts/dtc/fdtoverlay -o $@ -i $(real-prereqs)
@@ -360,22 +349,27 @@ $(multi-dtb-y): FORCE 
	$(call if_changed,fdtoverlay)

$(call multi_depend, $(multi-dtb-y), .dtb, -dtbs)



ifneq ($(CHECK_DTBS)$(CHECK_DT_BINDING),)

DT_CHECKER ?= dt-validate

DT_CHECKER_FLAGS ?= $(if $(DT_SCHEMA_FILES),-l $(DT_SCHEMA_FILES),-m)

DT_BINDING_DIR := Documentation/devicetree/bindings

DT_TMP_SCHEMA := $(objtree)/$(DT_BINDING_DIR)/processed-schema.json



quiet_cmd_dtb_check =	CHECK   $@

      cmd_dtb_check =	$(DT_CHECKER) $(DT_CHECKER_FLAGS) -u $(srctree)/$(DT_BINDING_DIR) -p $(DT_TMP_SCHEMA) $@

      cmd_dtb_check =	$(DT_CHECKER) $(DT_CHECKER_FLAGS) -u $(srctree)/$(DT_BINDING_DIR) -p $(DT_TMP_SCHEMA) $@ || true

endif



define rule_dtc

	$(call cmd_and_fixdep,dtc)

	$(call cmd,dtb_check)

endef



$(obj)/%.dt.yaml: $(src)/%.dts $(DTC) $(DT_TMP_SCHEMA) FORCE

$(obj)/%.dtb: $(src)/%.dts $(DTC) $(DT_TMP_SCHEMA) FORCE

	$(call if_changed_rule,dtc)



$(obj)/%.dtbo: $(src)/%.dts $(DTC) FORCE

	$(call if_changed_dep,dtc)



dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp)



# Bzip2

scripts/dtc/Makefile

+0 −13
Original line number Diff line number Diff line
@@ -17,20 +17,7 @@ fdtoverlay-objs := $(libfdt) fdtoverlay.o util.o 


# Source files need to get at the userspace version of libfdt_env.h to compile

HOST_EXTRACFLAGS += -I $(srctree)/$(src)/libfdt



ifeq ($(shell pkg-config --exists yaml-0.1 2>/dev/null && echo yes),)

ifneq ($(CHECK_DT_BINDING)$(CHECK_DTBS),)

$(error dtc needs libyaml for DT schema validation support. \

	Install the necessary libyaml development package.)

endif

HOST_EXTRACFLAGS += -DNO_YAML

else

dtc-objs	+= yamltree.o

# To include <yaml.h> installed in a non-default path

HOSTCFLAGS_yamltree.o := $(shell pkg-config --cflags yaml-0.1)

# To link libyaml installed in a non-default path

HOSTLDLIBS_dtc	:= $(shell pkg-config --libs yaml-0.1)

endif



# Generated files need one more search path to include headers in source tree

HOSTCFLAGS_dtc-lexer.lex.o := -I $(srctree)/$(src)

scripts/dtc/update-dtc-source.sh

+1 −1
Original line number Diff line number Diff line
@@ -32,7 +32,7 @@ DTC_UPSTREAM_PATH=`pwd`/../dtc 
DTC_LINUX_PATH=`pwd`/scripts/dtc



DTC_SOURCE="checks.c data.c dtc.c dtc.h flattree.c fstree.c livetree.c srcpos.c \

		srcpos.h treesource.c util.c util.h version_gen.h yamltree.c \

		srcpos.h treesource.c util.c util.h version_gen.h \

		dtc-lexer.l dtc-parser.y"

LIBFDT_SOURCE="fdt.c fdt.h fdt_addresses.c fdt_empty_tree.c \

		fdt_overlay.c fdt_ro.c fdt_rw.c fdt_strerror.c fdt_sw.c \