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1 | # | |
2 | # Device Tree Control | |
3 | # | |
4 | ||
5 | config SUPPORT_OF_CONTROL | |
6 | bool | |
7 | ||
8 | menu "Device Tree Control" | |
9 | depends on SUPPORT_OF_CONTROL | |
10 | ||
11 | config OF_CONTROL | |
12 | bool "Run-time configuration via Device Tree" | |
13 | help | |
14 | This feature provides for run-time configuration of U-Boot | |
15 | via a flattened device tree. | |
16 | ||
17 | config SPL_OF_CONTROL | |
18 | bool "Enable run-time configuration via Device Tree in SPL" | |
19 | depends on SPL && OF_CONTROL | |
20 | help | |
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. | |
24 | ||
25 | choice | |
26 | prompt "Provider of DTB for DT control" | |
27 | depends on OF_CONTROL | |
28 | ||
29 | config OF_SEPARATE | |
30 | bool "Separate DTB for DT control" | |
31 | depends on !SANDBOX | |
32 | help | |
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. | |
35 | ||
36 | config OF_EMBED | |
37 | bool "Embedded DTB for DT control" | |
38 | help | |
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. | |
43 | ||
44 | config OF_HOSTFILE | |
45 | bool "Host filed DTB for DT control" | |
46 | depends on SANDBOX | |
47 | help | |
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. | |
51 | ||
52 | endchoice | |
53 | ||
54 | config DEFAULT_DEVICE_TREE | |
55 | string "Default Device Tree for DT control" | |
56 | depends on OF_CONTROL | |
57 | help | |
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> | |
61 | ||
62 | config OF_LIST | |
63 | string "List of device tree files to include for DT control" | |
64 | depends on SPL_LOAD_FIT | |
65 | default DEFAULT_DEVICE_TREE | |
66 | help | |
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>. | |
72 | ||
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" | |
80 | help | |
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 | |
86 | discard. | |
87 | ||
88 | config SPL_OF_PLATDATA | |
89 | bool "Generate platform data for use in SPL" | |
90 | depends on SPL_OF_CONTROL | |
91 | help | |
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. | |
97 | ||
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 | |
102 | overhead. | |
103 | ||
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 | |
107 | information. | |
108 | ||
109 | endmenu |