scripts/dtc/dtx_diff

   1 #! /bin/bash
   2 # SPDX-License-Identifier: GPL-2.0-only
   3
   4 # Copyright (C) 2015 Frank Rowand
   5 #
   6
   7
   8 usage() {
   9
  10         # use spaces instead of tabs in the usage message
  11         cat >&2 <<eod
  12
  13 Usage:
  14
  15    `basename $0` DTx
  16         decompile DTx
  17
  18    `basename $0` DTx_1 DTx_2
  19         diff DTx_1 and DTx_2
  20
  21
  22       --annotate    synonym for -T
  23       --color       synonym for -c (requires diff with --color support)
  24        -c           enable colored output
  25        -f           print full dts in diff (--unified=99999)
  26        -h           synonym for --help
  27        -help        synonym for --help
  28       --help        print this message and exit
  29        -s SRCTREE   linux kernel source tree is at path SRCTREE
  30                         (default is current directory)
  31        -S           linux kernel source tree is at root of current git repo
  32        -T           annotate output .dts with input source file and line
  33                         (-T -T for more details)
  34        -u           unsorted, do not sort DTx
  35
  36
  37 Each DTx is processed by the dtc compiler to produce a sorted dts source
  38 file.  If DTx is a dts source file then it is pre-processed in the same
  39 manner as done for the compile of the dts source file in the Linux kernel
  40 build system ('#include' and '/include/' directives are processed).
  41
  42 If two DTx are provided, the resulting dts source files are diffed.
  43
  44 If DTx is a directory, it is treated as a DT subtree, such as
  45   /proc/device-tree.
  46
  47 If DTx contains the binary blob magic value in the first four bytes,
  48   it is treated as a binary blob (aka .dtb or FDT).
  49
  50 Otherwise DTx is treated as a dts source file (aka .dts).
  51
  52    If this script is not run from the root of the linux source tree,
  53    and DTx utilizes '#include' or '/include/' then the path of the
  54    linux source tree can be provided by '-s SRCTREE' or '-S' so that
  55    include paths will be set properly.
  56
  57    The shell variable \${ARCH} must provide the architecture containing
  58    the dts source file for include paths to be set properly for '#include'
  59    or '/include/' to be processed.
  60
  61    If DTx_1 and DTx_2 are in different architectures, then this script
  62    may not work since \${ARCH} is part of the include path.  The following
  63    workaround can be used:
  64
  65       `basename $0` ARCH=arch_of_dtx_1 DTx_1 >tmp_dtx_1.dts
  66       `basename $0` ARCH=arch_of_dtx_2 DTx_2 >tmp_dtx_2.dts
  67       `basename $0` tmp_dtx_1.dts tmp_dtx_2.dts
  68       rm tmp_dtx_1.dts tmp_dtx_2.dts
  69
  70    If DTx_1 and DTx_2 are in different directories, then this script will
  71    add the path of DTx_1 and DTx_2 to the include paths.  If DTx_2 includes
  72    a local file that exists in both the path of DTx_1 and DTx_2 then the
  73    file in the path of DTx_1 will incorrectly be included.  Possible
  74    workaround:
  75
  76       `basename $0` DTx_1 >tmp_dtx_1.dts
  77       `basename $0` DTx_2 >tmp_dtx_2.dts
  78       `basename $0` tmp_dtx_1.dts tmp_dtx_2.dts
  79       rm tmp_dtx_1.dts tmp_dtx_2.dts
  80
  81 eod
  82 }
  83
  84
  85 compile_to_dts() {
  86
  87         dtx="$1"
  88         dtc_include="$2"
  89
  90         if [ -d "${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} ${dtc_include} -I dts ) ; then
 117                         return
 118                 fi
 119
 120                 echo ""                                                      >&2
 121                 echo "Possible hints to resolve the above error:"            >&2
 122                 echo "  (hints might not fix the problem)"                   >&2
 123
 124                 hint_given=0
 125
 126                 if [ "${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 ${dtx_arch} is in file path,"   >&2
 138                         echo "  but does not match shell variable \$ARCH"    >&2
 139                         echo "  >>\$ARCH<< is: >>${ARCH}<<"                  >&2
 140                 fi
 141
 142                 if [ ! -d ${srctree}/arch/${ARCH} ] ; then
 143                         hint_given=1
 144                         echo ""                                              >&2
 145                         echo "  ${srctree}/arch/${ARCH}/ does not exist"     >&2
 146                         echo "  Is \$ARCH='${ARCH}' correct?"                >&2
 147                         echo "  Possible fix: use '-s' option"               >&2
 148
 149                         git_root=`git rev-parse --show-toplevel 2>/dev/null`
 150                         if [ -d ${git_root}/arch/ ] ; then
 151                                 echo "  Possible fix: use '-S' option"       >&2
 152                         fi
 153                 fi
 154
 155                 if [ $hint_given = 0 ] ; then
 156                         echo ""                                              >&2
 157                         echo "  No hints available."                         >&2
 158                 fi
 159
 160                 echo ""                                                      >&2
 161
 162                 exit 3
 163
 164         else
 165                 echo ""                                                     >&2
 166                 echo "ERROR: ${dtx} does not exist or is not readable"      >&2
 167                 echo ""                                                     >&2
 168                 exit 2
 169         fi
 170
 171 }
 172
 173
 174 # -----  start of script
 175
 176 annotate=""
 177 cmd_diff=0
 178 diff_flags="-u"
 179 diff_color=""
 180 dtx_file_1=""
 181 dtx_file_2=""
 182 dtc_sort="-s"
 183 help=0
 184 srctree=""
 185
 186
 187 while [ $# -gt 0 ] ; do
 188
 189         case $1 in
 190
 191         -c | --color )
 192                 if diff --color /dev/null /dev/null 2>/dev/null ; then
 193                         diff_color="--color=always"
 194                 fi
 195                 shift
 196                 ;;
 197
 198         -f )
 199                 diff_flags="--unified=999999"
 200                 shift
 201                 ;;
 202
 203         -h | -help | --help )
 204                 help=1
 205                 shift
 206                 ;;
 207
 208         -s )
 209                 srctree="$2"
 210                 shift 2
 211                 ;;
 212
 213         -S )
 214                 git_root=`git rev-parse --show-toplevel 2>/dev/null`
 215                 srctree="${git_root}"
 216                 shift
 217                 ;;
 218
 219         -T | --annotate )
 220                 if [ "${annotate}"  = "" ] ; then
 221                         annotate="-T"
 222                 elif [ "${annotate}"  = "-T" ] ; then
 223                         annotate="-T -T"
 224                 fi
 225                 shift
 226                 ;;
 227         -u )
 228                 dtc_sort=""
 229                 shift
 230                 ;;
 231
 232         *)
 233                 if [ "${dtx_file_1}"  = "" ] ; then
 234                         dtx_file_1="$1"
 235                 elif [ "${dtx_file_2}" = "" ] ; then
 236                         dtx_file_2="$1"
 237                 else
 238                         echo ""                                             >&2
 239                         echo "ERROR: Unexpected parameter: $1"              >&2
 240                         echo ""                                             >&2
 241                         exit 2
 242                 fi
 243                 shift
 244                 ;;
 245
 246         esac
 247
 248 done
 249
 250 if [ "${srctree}" = "" ] ; then
 251         srctree="."
 252 fi
 253
 254 if [ "${dtx_file_2}" != "" ]; then
 255         cmd_diff=1
 256 fi
 257
 258 if (( ${help} )) ; then
 259         usage
 260         exit 1
 261 fi
 262
 263 # this must follow check for ${help}
 264 if [ "${dtx_file_1}" = "" ]; then
 265         echo ""                                                             >&2
 266         echo "ERROR: parameter DTx required"                                >&2
 267         echo ""                                                             >&2
 268         exit 2
 269 fi
 270
 271
 272 # -----  prefer dtc from linux kernel, allow fallback to dtc in $PATH
 273
 274 if [ "${KBUILD_OUTPUT:0:2}" = ".." ] ; then
 275         __KBUILD_OUTPUT="${srctree}/${KBUILD_OUTPUT}"
 276 elif [ "${KBUILD_OUTPUT}" = "" ] ; then
 277         __KBUILD_OUTPUT="."
 278 else
 279         __KBUILD_OUTPUT="${KBUILD_OUTPUT}"
 280 fi
 281
 282 DTC="${__KBUILD_OUTPUT}/scripts/dtc/dtc"
 283
 284 if [ ! -x ${DTC} ] ; then
 285         __DTC="dtc"
 286         if grep -q "^CONFIG_DTC=y" ${__KBUILD_OUTPUT}/.config 2>/dev/null; then
 287                 make_command='
 288          make scripts'
 289         else
 290                 make_command='
 291          Enable CONFIG_DTC in the kernel configuration
 292          make scripts'
 293         fi
 294         if ( ! which ${__DTC} >/dev/null ) ; then
 295
 296                 # use spaces instead of tabs in the error message
 297                 cat >&2 <<eod
 298
 299 ERROR: unable to find a 'dtc' program
 300
 301    Preferred 'dtc' (built from Linux kernel source tree) was not found or
 302    is not executable.
 303
 304       'dtc' is: ${DTC}
 305
 306       If it does not exist, create it from the root of the Linux source tree:
 307 ${make_command}
 308
 309       If not at the root of the Linux kernel source tree -s SRCTREE or -S
 310       may need to be specified to find 'dtc'.
 311
 312       If 'O=\${dir}' is specified in your Linux builds, this script requires
 313       'export KBUILD_OUTPUT=\${dir}' or add \${dir}/scripts/dtc to \$PATH
 314       before running.
 315
 316       If \${KBUILD_OUTPUT} is a relative path, then '-s SRCDIR', -S, or run
 317       this script from the root of the Linux kernel source tree is required.
 318
 319    Fallback '${__DTC}' was also not in \${PATH} or is not executable.
 320
 321 eod
 322                 exit 2
 323         fi
 324         DTC=${__DTC}
 325 fi
 326
 327
 328 # -----  cpp and dtc flags same as for linux source tree build of .dtb files,
 329 #        plus directories of the dtx file(s)
 330
 331 dtx_path_1_dtc_include="-i `dirname ${dtx_file_1}`"
 332
 333 dtx_path_2_dtc_include=""
 334 if (( ${cmd_diff} )) ; then
 335         dtx_path_2_dtc_include="-i `dirname ${dtx_file_2}`"
 336 fi
 337
 338 cpp_flags="\
 339         -nostdinc                                  \
 340         -I${srctree}/scripts/dtc/include-prefixes  \
 341         -undef -D__DTS__"
 342
 343 DTC="\
 344         ${DTC}                                     \
 345         -i ${srctree}/scripts/dtc/include-prefixes \
 346         -O dts -qq -f ${dtc_sort} ${annotate} -o -"
 347
 348
 349 # -----  do the diff or decompile
 350
 351 if (( ${cmd_diff} )) ; then
 352
 353         diff ${diff_flags} ${diff_color} --label "${dtx_file_1}" --label "${dtx_file_2}" \
 354                 <(compile_to_dts "${dtx_file_1}" "${dtx_path_1_dtc_include}") \
 355                 <(compile_to_dts "${dtx_file_2}" "${dtx_path_2_dtc_include}")
 356
 357 else
 358
 359         compile_to_dts "${dtx_file_1}" "${dtx_path_1_dtc_include}"
 360
 361 fi