| # | |
| # Device Tree Control | |
| # | |
| config SUPPORT_OF_CONTROL | |
| bool | |
| menu "Device Tree Control" | |
| depends on SUPPORT_OF_CONTROL | |
| config OF_CONTROL | |
| bool "Run-time configuration via Device Tree" | |
| help | |
| This feature provides for run-time configuration of U-Boot | |
| via a flattened device tree. | |
| config OF_BOARD_FIXUP | |
| bool "Board-specific manipulation of Device Tree" | |
| help | |
| In certain circumstances it is necessary to be able to modify | |
| U-Boot's device tree (e.g. to delete device from it). This option | |
| make the Device Tree writeable and provides a board-specific | |
| "board_fix_fdt" callback (called during pre-relocation time), which | |
| enables the board initialization to modifiy the Device Tree. The | |
| modified copy is subsequently used by U-Boot after relocation. | |
| 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 | |
| config OF_SEPARATE | |
| bool "Separate DTB for DT control" | |
| depends on !SANDBOX | |
| help | |
| If this option is enabled, the device tree will be built and | |
| placed as a separate u-boot.dtb file alongside the U-Boot image. | |
| config OF_EMBED | |
| 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. 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" | |
| depends on SANDBOX | |
| help | |
| If this option is enabled, DTB will be read from a file on startup. | |
| This is only useful for Sandbox. Use the -d flag to U-Boot to | |
| specify the file to read. | |
| endchoice | |
| 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 && SPL_CLK | |
| default "clocks clock-names interrupt-parent" if SPL_PINCTRL | |
| 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 |