diff options
| -rw-r--r-- | doc/develop/devicetree/control.rst | 18 | ||||
| -rw-r--r-- | dts/Kconfig | 9 | ||||
| -rw-r--r-- | scripts/Makefile.lib | 3 |
3 files changed, 30 insertions, 0 deletions
diff --git a/doc/develop/devicetree/control.rst b/doc/develop/devicetree/control.rst index 0e6f85d5af..c71570d64b 100644 --- a/doc/develop/devicetree/control.rst +++ b/doc/develop/devicetree/control.rst @@ -182,6 +182,24 @@ main file, in this order:: Only one of these is selected but of course you can #include another one within that file, to create a hierarchy of shared files. + +External .dtsi fragments +------------------------ + +Apart from describing the hardware present, U-Boot also uses its +control dtb for various configuration purposes. For example, the +public key(s) used for Verified Boot are embedded in a specific format +in a /signature node. + +As mentioned above, the U-Boot build system automatically includes a +`*-u-boot.dtsi` file, if found, containing U-Boot specific +quirks. However, some data, such as the mentioned public keys, are not +appropriate for upstream U-Boot but are better kept and maintained +outside the U-Boot repository. You can use CONFIG_DEVICE_TREE_INCLUDES +to specify a list of .dtsi files that will also be included when +building .dtb files. + + Relocation, SPL and TPL ----------------------- diff --git a/dts/Kconfig b/dts/Kconfig index fb7df533f9..4de1a70efc 100644 --- a/dts/Kconfig +++ b/dts/Kconfig @@ -147,6 +147,15 @@ config DEFAULT_DEVICE_TREE It can be overridden from the command line: $ make DEVICE_TREE=<device-tree-name> +config DEVICE_TREE_INCLUDES + string "Extra .dtsi files to include when building DT control" + depends on OF_CONTROL + help + U-Boot's control .dtb is usually built from an in-tree .dts + file, plus (if available) an in-tree U-Boot-specific .dtsi + file. This option specifies a space-separated list of extra + .dtsi files that will also be used. + config OF_LIST string "List of device tree files to include for DT control" depends on SPL_LOAD_FIT || MULTI_DTB_FIT diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 3de78d9947..93cb09ac61 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -320,8 +320,11 @@ 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 $<; $(if $(u_boot_dtsi),echo '$(pound)include "$(u_boot_dtsi)"')) > $(pre-tmp); \ + $(foreach f,$(subst $(quote),,$(CONFIG_DEVICE_TREE_INCLUDES)), \ + echo '$(pound)include "$(f)"' >> $(pre-tmp);) \ $(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $(pre-tmp) ; \ $(DTC) -O dtb -o $@ -b 0 \ -i $(dir $<) $(DTC_FLAGS) \ |