Create script to diff device trees. The device tree can be in any of the forms recognized by the dtc compiler: - source - binary blob - file system tree (from /proc/devicetree) If the device tree is a source file, then it is pre-processed in the same way as it would be when built in the linux kernel source tree before diffing.
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| 1 | +#! /bin/bash | |
| 2 | + | |
| 3 | +# Copyright (C) 2015 Frank Rowand | |
| 4 | +# | |
| 5 | +# This program is free software; you can redistribute it and/or modify | |
| 6 | +# it under the terms of the GNU General Public License as published by | |
| 7 | +# the Free Software Foundation; version 2 of the License. | |
| 8 | + | |
| 9 | + | |
| 10 | +usage() { | |
| 11 | + | |
| 12 | + # use spaces instead of tabs in the usage message | |
| 13 | + cat >&2 <<eod | |
| 14 | + | |
| 15 | +Usage: | |
| 16 | + | |
| 17 | + `basename $0` DTx | |
| 18 | + decompile DTx | |
| 19 | + | |
| 20 | + `basename $0` DTx_1 DTx_2 | |
| 21 | + diff DTx_1 and DTx_2 | |
| 22 | + | |
| 23 | + | |
| 24 | + -f print full dts in diff (--unified=99999) | |
| 25 | + -h synonym for --help | |
| 26 | + -help synonym for --help | |
| 27 | + --help print this message and exit | |
| 28 | + -s SRCTREE linux kernel source tree is at path SRCTREE | |
| 29 | + (default is current directory) | |
| 30 | + -S linux kernel source tree is at root of current git repo | |
| 31 | + -u unsorted, do not sort DTx | |
| 32 | + | |
| 33 | + | |
| 34 | +Each DTx is processed by the dtc compiler to produce a sorted dts source | |
| 35 | +file. If DTx is a dts source file then it is pre-processed in the same | |
| 36 | +manner as done for the compile of the dts source file in the Linux kernel | |
| 37 | +build system ('#include' and '/include/' directives are processed). | |
| 38 | + | |
| 39 | +If two DTx are provided, the resulting dts source files are diffed. | |
| 40 | + | |
| 41 | +If DTx is a directory, it is treated as a DT subtree, such as | |
| 42 | + /proc/device-tree. | |
| 43 | + | |
| 44 | +If DTx contains the binary blob magic value in the first four bytes, | |
| 45 | + it is treated as a binary blob (aka .dtb or FDT). | |
| 46 | + | |
| 47 | +Otherwise DTx is treated as a dts source file (aka .dts). | |
| 48 | + | |
| 49 | + If this script is not run from the root of the linux source tree, | |
| 50 | + and DTx utilizes '#include' or '/include/' then the path of the | |
| 51 | + linux source tree can be provided by '-s SRCTREE' or '-S' so that | |
| 52 | + include paths will be set properly. | |
| 53 | + | |
| 54 | + The shell variable \${ARCH} must provide the architecture containing | |
| 55 | + the dts source file for include paths to be set properly for '#include' | |
| 56 | + or '/include/' to be processed. | |
| 57 | + | |
| 58 | + If DTx_1 and DTx_2 are in different architectures, then this script | |
| 59 | + may not work since \${ARCH} is part of the include path. Two possible | |
| 60 | + workarounds: | |
| 61 | + | |
| 62 | + `basename $0` \\ | |
| 63 | + <(ARCH=arch_of_dtx_1 `basename $0` DTx_1) \\ | |
| 64 | + <(ARCH=arch_of_dtx_2 `basename $0` DTx_2) | |
| 65 | + | |
| 66 | + `basename $0` ARCH=arch_of_dtx_1 DTx_1 >tmp_dtx_1.dts | |
| 67 | + `basename $0` ARCH=arch_of_dtx_2 DTx_2 >tmp_dtx_2.dts | |
| 68 | + `basename $0` tmp_dtx_1.dts tmp_dtx_2.dts | |
| 69 | + rm tmp_dtx_1.dts tmp_dtx_2.dts | |
| 70 | + | |
| 71 | + If DTx_1 and DTx_2 are in different directories, then this script will | |
| 72 | + add the path of DTx_1 and DTx_2 to the include paths. If DTx_2 includes | |
| 73 | + a local file that exists in both the path of DTx_1 and DTx_2 then the | |
| 74 | + file in the path of DTx_1 will incorrectly be included. Possible | |
| 75 | + workaround: | |
| 76 | + | |
| 77 | + `basename $0` DTx_1 >tmp_dtx_1.dts | |
| 78 | + `basename $0` DTx_2 >tmp_dtx_2.dts | |
| 79 | + `basename $0` tmp_dtx_1.dts tmp_dtx_2.dts | |
| 80 | + rm tmp_dtx_1.dts tmp_dtx_2.dts | |
| 81 | + | |
| 82 | +eod | |
| 83 | +} | |
| 84 | + | |
| 85 | + | |
| 86 | +compile_to_dts() { | |
| 87 | + | |
| 88 | + dtx="$1" | |
| 89 | + | |
| 90 | + if [ -d "${dtx}" ] ; then | |
| 91 | + | |
| 92 | + # ----- input is file tree | |
| 93 | + | |
| 94 | + if ( ! ${DTC} -I fs ${dtx} ) ; then | |
| 95 | + exit 3 | |
| 96 | + fi | |
| 97 | + | |
| 98 | + elif [ -f "${dtx}" ] && [ -r "${dtx}" ] ; then | |
| 99 | + | |
| 100 | + magic=`hexdump -n 4 -e '/1 "%02x"' ${dtx}` | |
| 101 | + if [ "${magic}" = "d00dfeed" ] ; then | |
| 102 | + | |
| 103 | + # ----- input is FDT (binary blob) | |
| 104 | + | |
| 105 | + if ( ! ${DTC} -I dtb ${dtx} ) ; then | |
| 106 | + exit 3 | |
| 107 | + fi | |
| 108 | + | |
| 109 | + return | |
| 110 | + | |
| 111 | + fi | |
| 112 | + | |
| 113 | + # ----- input is DTS (source) | |
| 114 | + | |
| 115 | + if ( cpp ${cpp_flags} -x assembler-with-cpp ${dtx} \ | |
| 116 | + | ${DTC} -I dts ) ; then | |
| 117 | + return | |
| 118 | + fi | |
| 119 | + | |
| 120 | + echo "" >&2 | |
| 121 | + echo "Possible hints to resolve the above error:" >&2 | |
| 122 | + echo " (hints might not fix the problem)" >&2 | |
| 123 | + | |
| 124 | + hint_given=0 | |
| 125 | + | |
| 126 | + if [ "${ARCH}" = "" ] ; then | |
| 127 | + hint_given=1 | |
| 128 | + echo "" >&2 | |
| 129 | + echo " shell variable \$ARCH not set" >&2 | |
| 130 | + fi | |
| 131 | + | |
| 132 | + dtx_arch=`echo "/${dtx}" | sed -e 's|.*/arch/||' -e 's|/.*||'` | |
| 133 | + | |
| 134 | + if [ "${dtx_arch}" != "" -a "${dtx_arch}" != "${ARCH}" ] ; then | |
| 135 | + hint_given=1 | |
| 136 | + echo "" >&2 | |
| 137 | + echo " architecture ${dtx_arch} is in file path," >&2 | |
| 138 | + echo " but does not match shell variable \$ARCH" >&2 | |
| 139 | + echo " (${ARCH}) does not match shell variable" >&2 | |
| 140 | + echo " \$ARCH (${ARCH})" >&2 | |
| 141 | + fi | |
| 142 | + | |
| 143 | + if [ ! -d ${srctree}/arch/${ARCH} ] ; then | |
| 144 | + hint_given=1 | |
| 145 | + echo "" >&2 | |
| 146 | + echo " ${srctree}/arch/${ARCH}/ does not exist" >&2 | |
| 147 | + echo " Is \$ARCH='${ARCH}' correct?" >&2 | |
| 148 | + echo " Possible fix: use '-s' option" >&2 | |
| 149 | + | |
| 150 | + git_root=`git rev-parse --show-toplevel 2>/dev/null` | |
| 151 | + if [ -d ${git_root}/arch/ ] ; then | |
| 152 | + echo " Possible fix: use '-S' option" >&2 | |
| 153 | + fi | |
| 154 | + fi | |
| 155 | + | |
| 156 | + if [ $hint_given = 0 ] ; then | |
| 157 | + echo "" >&2 | |
| 158 | + echo " No hints available." >&2 | |
| 159 | + fi | |
| 160 | + | |
| 161 | + echo "" >&2 | |
| 162 | + | |
| 163 | + exit 3 | |
| 164 | + | |
| 165 | + else | |
| 166 | + echo "" >&2 | |
| 167 | + echo "ERROR: ${dtx} does not exist or is not readable" >&2 | |
| 168 | + echo "" >&2 | |
| 169 | + exit 2 | |
| 170 | + fi | |
| 171 | + | |
| 172 | +} | |
| 173 | + | |
| 174 | + | |
| 175 | +# ----- start of script | |
| 176 | + | |
| 177 | +cmd_diff=0 | |
| 178 | +diff_flags="-u" | |
| 179 | +dtx_file_1="" | |
| 180 | +dtx_file_2="" | |
| 181 | +dtc_sort="-s" | |
| 182 | +help=0 | |
| 183 | +srctree="" | |
| 184 | + | |
| 185 | + | |
| 186 | +while [ $# -gt 0 ] ; do | |
| 187 | + | |
| 188 | + case $1 in | |
| 189 | + | |
| 190 | + -f ) | |
| 191 | + diff_flags="--unified=999999" | |
| 192 | + shift | |
| 193 | + ;; | |
| 194 | + | |
| 195 | + -h | -help | --help ) | |
| 196 | + help=1 | |
| 197 | + shift | |
| 198 | + ;; | |
| 199 | + | |
| 200 | + -s ) | |
| 201 | + srctree="$2" | |
| 202 | + shift 2 | |
| 203 | + ;; | |
| 204 | + | |
| 205 | + -S ) | |
| 206 | + git_root=`git rev-parse --show-toplevel 2>/dev/null` | |
| 207 | + srctree="${git_root}" | |
| 208 | + shift | |
| 209 | + ;; | |
| 210 | + | |
| 211 | + -u ) | |
| 212 | + dtc_sort="" | |
| 213 | + shift | |
| 214 | + ;; | |
| 215 | + | |
| 216 | + *) | |
| 217 | + if [ "${dtx_file_1}" = "" ] ; then | |
| 218 | + dtx_file_1="$1" | |
| 219 | + elif [ "${dtx_file_2}" = "" ] ; then | |
| 220 | + dtx_file_2="$1" | |
| 221 | + else | |
| 222 | + echo "" >&2 | |
| 223 | + echo "ERROR: Unexpected parameter: $1" >&2 | |
| 224 | + echo "" >&2 | |
| 225 | + exit 2 | |
| 226 | + fi | |
| 227 | + shift | |
| 228 | + ;; | |
| 229 | + | |
| 230 | + esac | |
| 231 | + | |
| 232 | +done | |
| 233 | + | |
| 234 | +if [ "${srctree}" = "" ] ; then | |
| 235 | + srctree="." | |
| 236 | +fi | |
| 237 | + | |
| 238 | +if [ "${dtx_file_2}" != "" ]; then | |
| 239 | + cmd_diff=1 | |
| 240 | +fi | |
| 241 | + | |
| 242 | +if (( ${help} )) ; then | |
| 243 | + usage | |
| 244 | + exit 1 | |
| 245 | +fi | |
| 246 | + | |
| 247 | +# this must follow check for ${help} | |
| 248 | +if [ "${dtx_file_1}" = "" ]; then | |
| 249 | + echo "" >&2 | |
| 250 | + echo "ERROR: parameter DTx required" >&2 | |
| 251 | + echo "" >&2 | |
| 252 | + exit 2 | |
| 253 | +fi | |
| 254 | + | |
| 255 | + | |
| 256 | +# ----- prefer dtc from linux kernel, allow fallback to dtc in $PATH | |
| 257 | + | |
| 258 | +if [ "${KBUILD_OUTPUT:0:2}" = ".." ] ; then | |
| 259 | + __KBUILD_OUTPUT="${srctree}/${KBUILD_OUTPUT}" | |
| 260 | +elif [ "${KBUILD_OUTPUT}" = "" ] ; then | |
| 261 | + __KBUILD_OUTPUT="." | |
| 262 | +else | |
| 263 | + __KBUILD_OUTPUT="${KBUILD_OUTPUT}" | |
| 264 | +fi | |
| 265 | + | |
| 266 | +DTC="${__KBUILD_OUTPUT}/scripts/dtc/dtc" | |
| 267 | + | |
| 268 | +if [ ! -x ${DTC} ] ; then | |
| 269 | + __DTC="dtc" | |
| 270 | + if ( ! which ${__DTC} >/dev/null ) ; then | |
| 271 | + | |
| 272 | + # use spaces instead of tabs in the error message | |
| 273 | + cat >&2 <<eod | |
| 274 | + | |
| 275 | +ERROR: unable to find a 'dtc' program | |
| 276 | + | |
| 277 | + Preferred 'dtc' (built from Linux kernel source tree) was not found or | |
| 278 | + is not executable. | |
| 279 | + | |
| 280 | + 'dtc' is: ${DTC} | |
| 281 | + | |
| 282 | + If it does not exist, create it from the root of the Linux source tree: | |
| 283 | + | |
| 284 | + 'make scripts'. | |
| 285 | + | |
| 286 | + If not at the root of the Linux kernel source tree -s SRCTREE or -S | |
| 287 | + may need to be specified to find 'dtc'. | |
| 288 | + | |
| 289 | + If 'O=\${dir}' is specified in your Linux builds, this script requires | |
| 290 | + 'export KBUILD_OUTPUT=\${dir}' or add \${dir}/scripts/dtc to \$PATH | |
| 291 | + before running. | |
| 292 | + | |
| 293 | + If \${KBUILD_OUTPUT} is a relative path, then '-s SRCDIR', -S, or run | |
| 294 | + this script from the root of the Linux kernel source tree is required. | |
| 295 | + | |
| 296 | + Fallback '${__DTC}' was also not in \${PATH} or is not executable. | |
| 297 | + | |
| 298 | +eod | |
| 299 | + exit 2 | |
| 300 | + fi | |
| 301 | + DTC=${__DTC} | |
| 302 | +fi | |
| 303 | + | |
| 304 | + | |
| 305 | +# ----- cpp and dtc flags same as for linux source tree build of .dtb files, | |
| 306 | +# plus directories of the dtx file(s) | |
| 307 | + | |
| 308 | +dtx_path_1_dtc_include="-i `dirname ${dtx_file_1}`" | |
| 309 | + | |
| 310 | +dtx_path_2_dtc_include="" | |
| 311 | +if (( ${cmd_diff} )) ; then | |
| 312 | + dtx_path_2_dtc_include="-i `dirname ${dtx_file_2}`" | |
| 313 | +fi | |
| 314 | + | |
| 315 | +cpp_flags="\ | |
| 316 | + -nostdinc \ | |
| 317 | + -I${srctree}/arch/${ARCH}/boot/dts \ | |
| 318 | + -I${srctree}/arch/${ARCH}/boot/dts/include \ | |
| 319 | + -I${srctree}/drivers/of/testcase-data \ | |
| 320 | + -undef -D__DTS__" | |
| 321 | + | |
| 322 | +dtc_flags="\ | |
| 323 | + -i ${srctree}/arch/${ARCH}/boot/dts/ \ | |
| 324 | + -i ${srctree}/kernel/dts \ | |
| 325 | + ${dtx_path_1_dtc_include} \ | |
| 326 | + ${dtx_path_2_dtc_include}" | |
| 327 | + | |
| 328 | +DTC="${DTC} ${dtc_flags} -O dts -qq -f ${dtc_sort} -o -" | |
| 329 | + | |
| 330 | + | |
| 331 | +# ----- do the diff or decompile | |
| 332 | + | |
| 333 | +if (( ${cmd_diff} )) ; then | |
| 334 | + | |
| 335 | + diff ${diff_flags} \ | |
| 336 | + <(compile_to_dts "${dtx_file_1}") \ | |
| 337 | + <(compile_to_dts "${dtx_file_2}") | |
| 338 | + | |
| 339 | +else | |
| 340 | + | |
| 341 | + compile_to_dts "${dtx_file_1}" | |
| 342 | + | |
| 343 | +fi | |