| # |
| # Device Tree Control |
| # |
| |
| config SUPPORT_OF_CONTROL |
| bool |
| |
| config DTC |
| bool |
| |
| menu "Device Tree Control" |
| depends on SUPPORT_OF_CONTROL |
| |
| config OF_CONTROL |
| bool "Run-time configuration via Device Tree" |
| select DTC |
| 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. |
| |
| config TPL_OF_CONTROL |
| bool "Enable run-time configuration via Device Tree in TPL" |
| depends on TPL && 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 TPL. |
| |
| config OF_LIVE |
| bool "Enable use of a live tree" |
| depends on OF_CONTROL |
| help |
| Normally U-Boot uses a flat device tree which saves space and |
| avoids the need to unpack the tree before use. However a flat |
| tree does not support modifcation from within U-Boot since it |
| can invalidate driver-model device tree offsets. This option |
| enables a live tree which is available after relocation, |
| and can be adjusted as needed. |
| |
| 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_BOARD |
| bool "Provided by the board at runtime" |
| depends on !SANDBOX |
| help |
| If this option is enabled, the device tree will be provided by |
| the board at runtime if the board supports it, instead of being |
| bundled with the image. |
| |
| 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 || MULTI_DTB_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, U-boot |
| or 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 DTB_RESELECT |
| bool "Support swapping dtbs at a later point in boot" |
| depends on MULTI_DTB_FIT |
| help |
| It is possible during initial boot you may need to use a generic |
| dtb until you can fully determine the board your running on. This |
| config allows boards to implement a function at a later point |
| during boot to switch to the "correct" dtb. |
| |
| config MULTI_DTB_FIT |
| bool "Support embedding several DTBs in a FIT image for u-boot" |
| help |
| This option provides hooks to allow U-boot to parse an |
| appended FIT image and enable board specific code to then select |
| the correct DTB to be used. Use this if you need to support |
| multiple DTBs but don't use the SPL. |
| |
| 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. |
| |
| config TPL_OF_PLATDATA |
| bool "Generate platform data for use in TPL" |
| depends on TPL_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 |
| |
| config MKIMAGE_DTC_PATH |
| string "Path to dtc binary for use within mkimage" |
| default "dtc" |
| help |
| The mkimage host tool will, in order to generate FIT images make |
| calls to the dtc application in order to create the output. In |
| some cases the system dtc may not support all required features |
| and the path to a different version should be given here. |