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 "Enable run-time configuration via Device Tree in SPL"
19 depends on SPL && OF_CONTROL
21 Some boards use device tree in U-Boot but only have 4KB of SRAM
22 which is not enough to support device tree. Enable this option to
23 allow such boards to be supported by U-Boot SPL.
26 prompt "Provider of DTB for DT control"
30 bool "Separate DTB for DT control"
33 If this option is enabled, the device tree will be built and
34 placed as a separate u-boot.dtb file alongside the U-Boot image.
37 bool "Embedded DTB for DT control"
39 If this option is enabled, the device tree will be picked up and
40 built into the U-Boot image. This is suitable for local debugging
41 and development only and is not recommended for production devices.
42 Boards in the mainline U-Boot tree should not use it.
45 bool "Host filed DTB for DT control"
48 If this option is enabled, DTB will be read from a file on startup.
49 This is only useful for Sandbox. Use the -d flag to U-Boot to
50 specify the file to read.
54 config DEFAULT_DEVICE_TREE
55 string "Default Device Tree for DT control"
58 This option specifies the default Device Tree used for DT control.
59 It can be overridden from the command line:
60 $ make DEVICE_TREE=<device-tree-name>
63 string "List of device tree files to include for DT control"
64 depends on SPL_LOAD_FIT
65 default DEFAULT_DEVICE_TREE
67 This option specifies a list of device tree files to use for DT
68 control. These will be packaged into a FIT. At run-time, SPL will
69 select the correct DT to use by examining the hardware (e.g.
70 reading a board ID value). This is a list of device tree files
71 (without the directory or .dtb suffix) separated by <space>.
73 config OF_SPL_REMOVE_PROPS
74 string "List of device tree properties to drop for SPL"
75 depends on SPL_OF_CONTROL
76 default "interrupt-parent" if SPL_PINCTRL_FULL && SPL_CLK
77 default "clocks clock-names interrupt-parent" if SPL_PINCTRL_FULL
78 default "pinctrl-0 pinctrl-names interrupt-parent" if SPL_CLK
79 default "pinctrl-0 pinctrl-names clocks clock-names interrupt-parent"
81 Since SPL normally runs in a reduced memory space, the device tree
82 is cut down to only what is needed to load and start U-Boot. Only
83 nodes marked with the property "u-boot,dm-pre-reloc" will be
84 included. In addition, some properties are not used by U-Boot and
85 can be discarded. This option defines the list of properties to
88 config SPL_OF_PLATDATA
89 bool "Generate platform data for use in SPL"
90 depends on SPL_OF_CONTROL
92 For very constrained SPL environments the overhead of decoding
93 device tree nodes and converting their contents into platform data
94 is too large. This overhead includes libfdt code as well as the
95 device tree contents itself. The latter is fairly compact, but the
96 former can add 3KB or more to a Thumb 2 Image.
98 This option enables generation of platform data from the device
99 tree as C code. This code creates devices using U_BOOT_DEVICE()
100 declarations. The benefit is that it allows driver code to access
101 the platform data directly in C structures, avoidin the libfdt
104 This option works by generating C structure declarations for each
105 compatible string, then adding platform data and U_BOOT_DEVICE
106 declarations for each node. See README.platdata for more