5 config SUPPORT_OF_CONTROL
11 menu "Device Tree Control"
12 depends on SUPPORT_OF_CONTROL
15 bool "Run-time configuration via Device Tree"
18 This feature provides for run-time configuration of U-Boot
19 via a flattened device tree.
22 bool "Board-specific manipulation of Device Tree"
24 In certain circumstances it is necessary to be able to modify
25 U-Boot's device tree (e.g. to delete device from it). This option
26 make the Device Tree writeable and provides a board-specific
27 "board_fix_fdt" callback (called during pre-relocation time), which
28 enables the board initialization to modifiy the Device Tree. The
29 modified copy is subsequently used by U-Boot after relocation.
32 bool "Enable run-time configuration via Device Tree in SPL"
33 depends on SPL && OF_CONTROL
35 Some boards use device tree in U-Boot but only have 4KB of SRAM
36 which is not enough to support device tree. Enable this option to
37 allow such boards to be supported by U-Boot SPL.
40 bool "Enable run-time configuration via Device Tree in TPL"
41 depends on TPL && OF_CONTROL
43 Some boards use device tree in U-Boot but only have 4KB of SRAM
44 which is not enough to support device tree. Enable this option to
45 allow such boards to be supported by U-Boot TPL.
48 bool "Enable use of a live tree"
51 Normally U-Boot uses a flat device tree which saves space and
52 avoids the need to unpack the tree before use. However a flat
53 tree does not support modifcation from within U-Boot since it
54 can invalidate driver-model device tree offsets. This option
55 enables a live tree which is available after relocation,
56 and can be adjusted as needed.
59 prompt "Provider of DTB for DT control"
63 bool "Separate DTB for DT control"
66 If this option is enabled, the device tree will be built and
67 placed as a separate u-boot.dtb file alongside the U-Boot image.
70 bool "Embedded DTB for DT control"
72 If this option is enabled, the device tree will be picked up and
73 built into the U-Boot image. This is suitable for local debugging
74 and development only and is not recommended for production devices.
75 Boards in the mainline U-Boot tree should not use it.
78 bool "Provided by the board at runtime"
81 If this option is enabled, the device tree will be provided by
82 the board at runtime if the board supports it, instead of being
83 bundled with the image.
86 bool "Host filed DTB for DT control"
89 If this option is enabled, DTB will be read from a file on startup.
90 This is only useful for Sandbox. Use the -d flag to U-Boot to
91 specify the file to read.
95 config DEFAULT_DEVICE_TREE
96 string "Default Device Tree for DT control"
99 This option specifies the default Device Tree used for DT control.
100 It can be overridden from the command line:
101 $ make DEVICE_TREE=<device-tree-name>
104 string "List of device tree files to include for DT control"
105 depends on SPL_LOAD_FIT || FIT_EMBED
106 default DEFAULT_DEVICE_TREE
108 This option specifies a list of device tree files to use for DT
109 control. These will be packaged into a FIT. At run-time, U-boot
110 or SPL will select the correct DT to use by examining the
111 hardware (e.g. reading a board ID value). This is a list of
112 device tree files (without the directory or .dtb suffix)
113 separated by <space>.
115 config OF_SPL_REMOVE_PROPS
116 string "List of device tree properties to drop for SPL"
117 depends on SPL_OF_CONTROL
118 default "interrupt-parent" if SPL_PINCTRL && SPL_CLK
119 default "clocks clock-names interrupt-parent" if SPL_PINCTRL
120 default "pinctrl-0 pinctrl-names interrupt-parent" if SPL_CLK
121 default "pinctrl-0 pinctrl-names clocks clock-names interrupt-parent"
123 Since SPL normally runs in a reduced memory space, the device tree
124 is cut down to only what is needed to load and start U-Boot. Only
125 nodes marked with the property "u-boot,dm-pre-reloc" will be
126 included. In addition, some properties are not used by U-Boot and
127 can be discarded. This option defines the list of properties to
130 config SPL_OF_PLATDATA
131 bool "Generate platform data for use in SPL"
132 depends on SPL_OF_CONTROL
134 For very constrained SPL environments the overhead of decoding
135 device tree nodes and converting their contents into platform data
136 is too large. This overhead includes libfdt code as well as the
137 device tree contents itself. The latter is fairly compact, but the
138 former can add 3KB or more to a Thumb 2 Image.
140 This option enables generation of platform data from the device
141 tree as C code. This code creates devices using U_BOOT_DEVICE()
142 declarations. The benefit is that it allows driver code to access
143 the platform data directly in C structures, avoidin the libfdt
146 This option works by generating C structure declarations for each
147 compatible string, then adding platform data and U_BOOT_DEVICE
148 declarations for each node. See README.platdata for more
151 config TPL_OF_PLATDATA
152 bool "Generate platform data for use in TPL"
153 depends on TPL_OF_CONTROL
155 For very constrained SPL environments the overhead of decoding
156 device tree nodes and converting their contents into platform data
157 is too large. This overhead includes libfdt code as well as the
158 device tree contents itself. The latter is fairly compact, but the
159 former can add 3KB or more to a Thumb 2 Image.
161 This option enables generation of platform data from the device
162 tree as C code. This code creates devices using U_BOOT_DEVICE()
163 declarations. The benefit is that it allows driver code to access
164 the platform data directly in C structures, avoidin the libfdt
167 This option works by generating C structure declarations for each
168 compatible string, then adding platform data and U_BOOT_DEVICE
169 declarations for each node. See README.platdata for more
174 config MKIMAGE_DTC_PATH
175 string "Path to dtc binary for use within mkimage"
178 The mkimage host tool will, in order to generate FIT images make
179 calls to the dtc application in order to create the output. In
180 some cases the system dtc may not support all required features
181 and the path to a different version should be given here.