1# 2# Device Tree Control 3# 4 5config SUPPORT_OF_CONTROL 6 bool 7 8menu "Device Tree Control" 9 depends on SUPPORT_OF_CONTROL 10 11config 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 17config 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 25choice 26 prompt "Provider of DTB for DT control" 27 depends on OF_CONTROL 28 29config 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 36config 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 44config 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 52endchoice 53 54config 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 62config 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 73config 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 88config 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 109endmenu 110