1# 2# Device Tree Control 3# 4 5config SUPPORT_OF_CONTROL 6 bool 7 8config DTC 9 bool 10 11config PYLIBFDT 12 bool 13 14config DTOC 15 bool 16 select PYLIBFDT 17 18config BINMAN 19 bool 20 select DTOC 21 22menu "Device Tree Control" 23 depends on SUPPORT_OF_CONTROL 24 25config OF_CONTROL 26 bool "Run-time configuration via Device Tree" 27 select DTC 28 help 29 This feature provides for run-time configuration of U-Boot 30 via a flattened device tree. 31 32config OF_BOARD_FIXUP 33 bool "Board-specific manipulation of Device Tree" 34 help 35 In certain circumstances it is necessary to be able to modify 36 U-Boot's device tree (e.g. to delete device from it). This option 37 make the Device Tree writeable and provides a board-specific 38 "board_fix_fdt" callback (called during pre-relocation time), which 39 enables the board initialization to modifiy the Device Tree. The 40 modified copy is subsequently used by U-Boot after relocation. 41 42config SPL_OF_CONTROL 43 bool "Enable run-time configuration via Device Tree in SPL" 44 depends on SPL && OF_CONTROL 45 help 46 Some boards use device tree in U-Boot but only have 4KB of SRAM 47 which is not enough to support device tree. Enable this option to 48 allow such boards to be supported by U-Boot SPL. 49 50config TPL_OF_CONTROL 51 bool "Enable run-time configuration via Device Tree in TPL" 52 depends on TPL && OF_CONTROL 53 help 54 Some boards use device tree in U-Boot but only have 4KB of SRAM 55 which is not enough to support device tree. Enable this option to 56 allow such boards to be supported by U-Boot TPL. 57 58config OF_LIVE 59 bool "Enable use of a live tree" 60 depends on OF_CONTROL 61 help 62 Normally U-Boot uses a flat device tree which saves space and 63 avoids the need to unpack the tree before use. However a flat 64 tree does not support modification from within U-Boot since it 65 can invalidate driver-model device tree offsets. This option 66 enables a live tree which is available after relocation, 67 and can be adjusted as needed. 68 69choice 70 prompt "Provider of DTB for DT control" 71 depends on OF_CONTROL 72 73config OF_SEPARATE 74 bool "Separate DTB for DT control" 75 depends on !SANDBOX 76 help 77 If this option is enabled, the device tree will be built and 78 placed as a separate u-boot.dtb file alongside the U-Boot image. 79 80config OF_EMBED 81 bool "Embedded DTB for DT control" 82 help 83 If this option is enabled, the device tree will be picked up and 84 built into the U-Boot image. This is suitable for local debugging 85 and development only and is not recommended for production devices. 86 Boards in the mainline U-Boot tree should not use it. 87 88config OF_BOARD 89 bool "Provided by the board at runtime" 90 depends on !SANDBOX 91 help 92 If this option is enabled, the device tree will be provided by 93 the board at runtime if the board supports it, instead of being 94 bundled with the image. 95 96config OF_HOSTFILE 97 bool "Host filed DTB for DT control" 98 depends on SANDBOX 99 help 100 If this option is enabled, DTB will be read from a file on startup. 101 This is only useful for Sandbox. Use the -d flag to U-Boot to 102 specify the file to read. 103 104config OF_PRIOR_STAGE 105 bool "Prior stage bootloader DTB for DT control" 106 help 107 If this option is enabled, the device tree used for DT 108 control will be read from a device tree binary, at a memory 109 location passed to U-Boot by the prior stage bootloader. 110 111endchoice 112 113config DEFAULT_DEVICE_TREE 114 string "Default Device Tree for DT control" 115 depends on OF_CONTROL 116 help 117 This option specifies the default Device Tree used for DT control. 118 It can be overridden from the command line: 119 $ make DEVICE_TREE=<device-tree-name> 120 121config OF_LIST 122 string "List of device tree files to include for DT control" 123 depends on SPL_LOAD_FIT || MULTI_DTB_FIT 124 default DEFAULT_DEVICE_TREE 125 help 126 This option specifies a list of device tree files to use for DT 127 control. These will be packaged into a FIT. At run-time, U-boot 128 or SPL will select the correct DT to use by examining the 129 hardware (e.g. reading a board ID value). This is a list of 130 device tree files (without the directory or .dtb suffix) 131 separated by <space>. 132 133 134config DTB_RESELECT 135 bool "Support swapping dtbs at a later point in boot" 136 depends on MULTI_DTB_FIT 137 help 138 It is possible during initial boot you may need to use a generic 139 dtb until you can fully determine the board your running on. This 140 config allows boards to implement a function at a later point 141 during boot to switch to the "correct" dtb. 142 143config MULTI_DTB_FIT 144 bool "Support embedding several DTBs in a FIT image for u-boot" 145 help 146 This option provides hooks to allow U-boot to parse an 147 appended FIT image and enable board specific code to then select 148 the correct DTB to be used. Use this if you need to support 149 multiple DTBs but don't use the SPL. 150 151 152config SPL_MULTI_DTB_FIT 153 depends on SPL_LOAD_FIT && SPL_OF_CONTROL && !SPL_OF_PLATDATA 154 bool "Support embedding several DTBs in a FIT image for the SPL" 155 help 156 This option provides the SPL with the ability to select its own 157 DTB at runtime from an appended FIT image containing several DTBs. 158 This allows using the same SPL binary on multiple platforms. 159 The primary purpose is to handle different versions of 160 the same platform without tweaking the platform code if the 161 differences can be expressed in the DTBs (common examples are: bus 162 capabilities, pad configurations). 163 164config SPL_OF_LIST 165 string "List of device tree files to include for DT control in SPL" 166 depends on SPL_MULTI_DTB_FIT 167 default OF_LIST 168 help 169 This option specifies a list of device tree files to use for DT 170 control in the SPL. These will be packaged into a FIT. At run-time, 171 the SPL will select the correct DT to use by examining the 172 hardware (e.g. reading a board ID value). This is a list of 173 device tree files (without the directory or .dtb suffix) 174 separated by <space>. 175 176choice 177 prompt "SPL OF LIST compression" 178 depends on SPL_MULTI_DTB_FIT 179 default SPL_MULTI_DTB_FIT_LZO 180 181config SPL_MULTI_DTB_FIT_LZO 182 bool "LZO" 183 depends on SYS_MALLOC_F 184 select SPL_LZO 185 help 186 Compress the FIT image containing the DTBs available for the SPL 187 using LZO compression. (requires lzop on host). 188 189config SPL_MULTI_DTB_FIT_GZIP 190 bool "GZIP" 191 depends on SYS_MALLOC_F 192 select SPL_GZIP 193 help 194 Compress the FIT image containing the DTBs available for the SPL 195 using GZIP compression. (requires gzip on host) 196 197config SPL_MULTI_DTB_FIT_NO_COMPRESSION 198 bool "No compression" 199 help 200 Do not compress the FIT image containing the DTBs available for the SPL. 201 Use this options only if LZO is not available and the DTBs are very small. 202endchoice 203 204choice 205 prompt "Location of uncompressed DTBs" 206 depends on (SPL_MULTI_DTB_FIT_GZIP || SPL_MULTI_DTB_FIT_LZO) 207 default SPL_MULTI_DTB_FIT_DYN_ALLOC if SYS_MALLOC_F 208 209config SPL_MULTI_DTB_FIT_DYN_ALLOC 210 bool "Dynamically allocate the memory" 211 depends on SYS_MALLOC_F 212 213config SPL_MULTI_DTB_FIT_USER_DEFINED_AREA 214 bool "User-defined location" 215endchoice 216 217config SPL_MULTI_DTB_FIT_UNCOMPRESS_SZ 218 hex "Size of memory reserved to uncompress the DTBs" 219 depends on (SPL_MULTI_DTB_FIT_GZIP || SPL_MULTI_DTB_FIT_LZO) 220 default 0x8000 221 help 222 This is the size of this area where the DTBs are uncompressed. 223 If this area is dynamically allocated, make sure that 224 SPL_SYS_MALLOC_F_LEN is big enough to contain it. 225 226config SPL_MULTI_DTB_FIT_USER_DEF_ADDR 227 hex "Address of memory where dtbs are uncompressed" 228 depends on SPL_MULTI_DTB_FIT_USER_DEFINED_AREA 229 help 230 the FIT image containing the DTBs is uncompressed in an area defined 231 at compilation time. This is the address of this area. It must be 232 aligned on 2-byte boundary. 233 234config OF_SPL_REMOVE_PROPS 235 string "List of device tree properties to drop for SPL" 236 depends on SPL_OF_CONTROL 237 default "interrupt-parent" if SPL_PINCTRL && SPL_CLK 238 default "clocks clock-names interrupt-parent" if SPL_PINCTRL 239 default "pinctrl-0 pinctrl-names interrupt-parent" if SPL_CLK 240 default "pinctrl-0 pinctrl-names clocks clock-names interrupt-parent" 241 help 242 Since SPL normally runs in a reduced memory space, the device tree 243 is cut down to only what is needed to load and start U-Boot. Only 244 nodes marked with the property "u-boot,dm-pre-reloc" will be 245 included. In addition, some properties are not used by U-Boot and 246 can be discarded. This option defines the list of properties to 247 discard. 248 249config SPL_OF_PLATDATA 250 bool "Generate platform data for use in SPL" 251 depends on SPL_OF_CONTROL 252 select DTOC 253 help 254 For very constrained SPL environments the overhead of decoding 255 device tree nodes and converting their contents into platform data 256 is too large. This overhead includes libfdt code as well as the 257 device tree contents itself. The latter is fairly compact, but the 258 former can add 3KB or more to a Thumb 2 Image. 259 260 This option enables generation of platform data from the device 261 tree as C code. This code creates devices using U_BOOT_DEVICE() 262 declarations. The benefit is that it allows driver code to access 263 the platform data directly in C structures, avoidin the libfdt 264 overhead. 265 266 This option works by generating C structure declarations for each 267 compatible string, then adding platform data and U_BOOT_DEVICE 268 declarations for each node. See of-plat.txt for more information. 269 270config TPL_OF_PLATDATA 271 bool "Generate platform data for use in TPL" 272 depends on TPL_OF_CONTROL 273 select DTOC 274 help 275 For very constrained SPL environments the overhead of decoding 276 device tree nodes and converting their contents into platform data 277 is too large. This overhead includes libfdt code as well as the 278 device tree contents itself. The latter is fairly compact, but the 279 former can add 3KB or more to a Thumb 2 Image. 280 281 This option enables generation of platform data from the device 282 tree as C code. This code creates devices using U_BOOT_DEVICE() 283 declarations. The benefit is that it allows driver code to access 284 the platform data directly in C structures, avoidin the libfdt 285 overhead. 286 287 This option works by generating C structure declarations for each 288 compatible string, then adding platform data and U_BOOT_DEVICE 289 declarations for each node. See of-plat.txt for more information. 290 291endmenu 292 293config MKIMAGE_DTC_PATH 294 string "Path to dtc binary for use within mkimage" 295 default "dtc" 296 help 297 The mkimage host tool will, in order to generate FIT images make 298 calls to the dtc application in order to create the output. In 299 some cases the system dtc may not support all required features 300 and the path to a different version should be given here. 301