5 config SUPPORT_OF_CONTROL
8 menu "Device Tree Control"
9 depends on SUPPORT_OF_CONTROL
12 bool "Run-time configuration via Device Tree"
14 This feature provides for run-time configuration of U-Boot
15 via a flattened device tree.
18 bool "Board-specific manipulation of Device Tree"
20 In certain circumstances it is necessary to be able to modify
21 U-Boot's device tree (e.g. to delete device from it). This option
22 make the Device Tree writeable and provides a board-specific
23 "board_fix_fdt" callback (called during pre-relocation time), which
24 enables the board initialization to modifiy the Device Tree. The
25 modified copy is subsequently used by U-Boot after relocation.
28 bool "Enable run-time configuration via Device Tree in SPL"
29 depends on SPL && OF_CONTROL
31 Some boards use device tree in U-Boot but only have 4KB of SRAM
32 which is not enough to support device tree. Enable this option to
33 allow such boards to be supported by U-Boot SPL.
36 bool "Enable run-time configuration via Device Tree in TPL"
37 depends on TPL && OF_CONTROL
39 Some boards use device tree in U-Boot but only have 4KB of SRAM
40 which is not enough to support device tree. Enable this option to
41 allow such boards to be supported by U-Boot TPL.
44 bool "Enable use of a live tree"
47 Normally U-Boot uses a flat device tree which saves space and
48 avoids the need to unpack the tree before use. However a flat
49 tree does not support modifcation from within U-Boot since it
50 can invalidate driver-model device tree offsets. This option
51 enables a live tree which is available after relocation,
52 and can be adjusted as needed.
55 prompt "Provider of DTB for DT control"
59 bool "Separate DTB for DT control"
62 If this option is enabled, the device tree will be built and
63 placed as a separate u-boot.dtb file alongside the U-Boot image.
66 bool "Embedded DTB for DT control"
68 If this option is enabled, the device tree will be picked up and
69 built into the U-Boot image. This is suitable for local debugging
70 and development only and is not recommended for production devices.
71 Boards in the mainline U-Boot tree should not use it.
74 bool "Provided by the board at runtime"
77 If this option is enabled, the device tree will be provided by
78 the board at runtime if the board supports it, instead of being
79 bundled with the image.
82 bool "Host filed DTB for DT control"
85 If this option is enabled, DTB will be read from a file on startup.
86 This is only useful for Sandbox. Use the -d flag to U-Boot to
87 specify the file to read.
91 config DEFAULT_DEVICE_TREE
92 string "Default Device Tree for DT control"
95 This option specifies the default Device Tree used for DT control.
96 It can be overridden from the command line:
97 $ make DEVICE_TREE=<device-tree-name>
100 string "List of device tree files to include for DT control"
101 depends on SPL_LOAD_FIT || FIT_EMBED
102 default DEFAULT_DEVICE_TREE
104 This option specifies a list of device tree files to use for DT
105 control. These will be packaged into a FIT. At run-time, U-boot
106 or SPL will select the correct DT to use by examining the
107 hardware (e.g. reading a board ID value). This is a list of
108 device tree files (without the directory or .dtb suffix)
109 separated by <space>.
111 config OF_SPL_REMOVE_PROPS
112 string "List of device tree properties to drop for SPL"
113 depends on SPL_OF_CONTROL
114 default "interrupt-parent" if SPL_PINCTRL && SPL_CLK
115 default "clocks clock-names interrupt-parent" if SPL_PINCTRL
116 default "pinctrl-0 pinctrl-names interrupt-parent" if SPL_CLK
117 default "pinctrl-0 pinctrl-names clocks clock-names interrupt-parent"
119 Since SPL normally runs in a reduced memory space, the device tree
120 is cut down to only what is needed to load and start U-Boot. Only
121 nodes marked with the property "u-boot,dm-pre-reloc" will be
122 included. In addition, some properties are not used by U-Boot and
123 can be discarded. This option defines the list of properties to
126 config SPL_OF_PLATDATA
127 bool "Generate platform data for use in SPL"
128 depends on SPL_OF_CONTROL
130 For very constrained SPL environments the overhead of decoding
131 device tree nodes and converting their contents into platform data
132 is too large. This overhead includes libfdt code as well as the
133 device tree contents itself. The latter is fairly compact, but the
134 former can add 3KB or more to a Thumb 2 Image.
136 This option enables generation of platform data from the device
137 tree as C code. This code creates devices using U_BOOT_DEVICE()
138 declarations. The benefit is that it allows driver code to access
139 the platform data directly in C structures, avoidin the libfdt
142 This option works by generating C structure declarations for each
143 compatible string, then adding platform data and U_BOOT_DEVICE
144 declarations for each node. See README.platdata for more
147 config TPL_OF_PLATDATA
148 bool "Generate platform data for use in TPL"
149 depends on TPL_OF_CONTROL
151 For very constrained SPL environments the overhead of decoding
152 device tree nodes and converting their contents into platform data
153 is too large. This overhead includes libfdt code as well as the
154 device tree contents itself. The latter is fairly compact, but the
155 former can add 3KB or more to a Thumb 2 Image.
157 This option enables generation of platform data from the device
158 tree as C code. This code creates devices using U_BOOT_DEVICE()
159 declarations. The benefit is that it allows driver code to access
160 the platform data directly in C structures, avoidin the libfdt
163 This option works by generating C structure declarations for each
164 compatible string, then adding platform data and U_BOOT_DEVICE
165 declarations for each node. See README.platdata for more