#
# Device Tree Control
#
-# TODO:
-# This feature is not currently supported for SPL,
-# but this restriction should be removed in the future.
config SUPPORT_OF_CONTROL
bool
This feature provides for run-time configuration of U-Boot
via a flattened device tree.
+config SPL_OF_CONTROL
+ bool "Enable run-time configuration via Device Tree in SPL"
+ depends on SPL && OF_CONTROL
+ help
+ Some boards use device tree in U-Boot but only have 4KB of SRAM
+ which is not enough to support device tree. Enable this option to
+ allow such boards to be supported by U-Boot SPL.
+
choice
prompt "Provider of DTB for DT control"
depends on OF_CONTROL
bool "Embedded DTB for DT control"
help
If this option is enabled, the device tree will be picked up and
- built into the U-Boot image.
+ built into the U-Boot image. This is suitable for local debugging
+ and development only and is not recommended for production devices.
+ Boards in the mainline U-Boot tree should not use it.
config OF_HOSTFILE
bool "Host filed DTB for DT control"
config DEFAULT_DEVICE_TREE
string "Default Device Tree for DT control"
+ depends on OF_CONTROL
help
This option specifies the default Device Tree used for DT control.
It can be overridden from the command line:
$ make DEVICE_TREE=<device-tree-name>
+config OF_LIST
+ string "List of device tree files to include for DT control"
+ depends on SPL_LOAD_FIT
+ default DEFAULT_DEVICE_TREE
+ help
+ This option specifies a list of device tree files to use for DT
+ control. These will be packaged into a FIT. At run-time, SPL will
+ select the correct DT to use by examining the hardware (e.g.
+ reading a board ID value). This is a list of device tree files
+ (without the directory or .dtb suffix) separated by <space>.
+
+config OF_SPL_REMOVE_PROPS
+ string "List of device tree properties to drop for SPL"
+ depends on SPL_OF_CONTROL
+ default "interrupt-parent" if SPL_PINCTRL_FULL && SPL_CLK
+ default "clocks clock-names interrupt-parent" if SPL_PINCTRL_FULL
+ default "pinctrl-0 pinctrl-names interrupt-parent" if SPL_CLK
+ default "pinctrl-0 pinctrl-names clocks clock-names interrupt-parent"
+ help
+ Since SPL normally runs in a reduced memory space, the device tree
+ is cut down to only what is needed to load and start U-Boot. Only
+ nodes marked with the property "u-boot,dm-pre-reloc" will be
+ included. In addition, some properties are not used by U-Boot and
+ can be discarded. This option defines the list of properties to
+ discard.
+
+config SPL_OF_PLATDATA
+ bool "Generate platform data for use in SPL"
+ depends on SPL_OF_CONTROL
+ help
+ For very constrained SPL environments the overhead of decoding
+ device tree nodes and converting their contents into platform data
+ is too large. This overhead includes libfdt code as well as the
+ device tree contents itself. The latter is fairly compact, but the
+ former can add 3KB or more to a Thumb 2 Image.
+
+ This option enables generation of platform data from the device
+ tree as C code. This code creates devices using U_BOOT_DEVICE()
+ declarations. The benefit is that it allows driver code to access
+ the platform data directly in C structures, avoidin the libfdt
+ overhead.
+
+ This option works by generating C structure declarations for each
+ compatible string, then adding platform data and U_BOOT_DEVICE
+ declarations for each node. See README.platdata for more
+ information.
+
endmenu