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.  Two possible
  63    workarounds:
  64
  65       `basename $0` \\
  66           <(ARCH=arch_of_dtx_1 `basename $0` DTx_1) \\
  67           <(ARCH=arch_of_dtx_2 `basename $0` DTx_2)
  68
  69       `basename $0` ARCH=arch_of_dtx_1 DTx_1 >tmp_dtx_1.dts
  70       `basename $0` ARCH=arch_of_dtx_2 DTx_2 >tmp_dtx_2.dts
  71       `basename $0` tmp_dtx_1.dts tmp_dtx_2.dts
  72       rm tmp_dtx_1.dts tmp_dtx_2.dts
  73
  74    If DTx_1 and DTx_2 are in different directories, then this script will
  75    add the path of DTx_1 and DTx_2 to the include paths.  If DTx_2 includes
  76    a local file that exists in both the path of DTx_1 and DTx_2 then the
  77    file in the path of DTx_1 will incorrectly be included.  Possible
  78    workaround:
  79
  80       `basename $0` DTx_1 >tmp_dtx_1.dts
  81       `basename $0` DTx_2 >tmp_dtx_2.dts
  82       `basename $0` tmp_dtx_1.dts tmp_dtx_2.dts
  83       rm tmp_dtx_1.dts tmp_dtx_2.dts
  84
  85 eod
  86 }
  87
  88
  89 compile_to_dts() {
  90
  91         dtx="$1"
  92         dtc_include="$2"
  93
  94         if [ -d "${dtx}" ] ; then
  95
  96                 # -----  input is file tree
  97
  98                 if ( ! ${DTC} -I fs ${dtx} ) ; then
  99                         exit 3
 100                 fi
 101
 102         elif [ -f "${dtx}" ] && [ -r "${dtx}" ] ; then
 103
 104                 magic=`hexdump -n 4 -e '/1 "%02x"' ${dtx}`
 105                 if [ "${magic}" = "d00dfeed" ] ; then
 106
 107                         # -----  input is FDT (binary blob)
 108
 109                         if ( ! ${DTC} -I dtb ${dtx} ) ; then
 110                                 exit 3
 111                         fi
 112
 113                         return
 114
 115                 fi
 116
 117                 # -----  input is DTS (source)
 118
 119                 if ( cpp ${cpp_flags} -x assembler-with-cpp ${dtx} \
 120                         | ${DTC} ${dtc_include} -I dts ) ; then
 121                         return
 122                 fi
 123
 124                 echo ""                                                      >&2
 125                 echo "Possible hints to resolve the above error:"            >&2
 126                 echo "  (hints might not fix the problem)"                   >&2
 127
 128                 hint_given=0
 129
 130                 if [ "${ARCH}" = "" ] ; then
 131                         hint_given=1
 132                         echo ""                                              >&2
 133                         echo "  shell variable \$ARCH not set"               >&2
 134                 fi
 135
 136                 dtx_arch=`echo "/${dtx}" | sed -e 's|.*/arch/||' -e 's|/.*||'`
 137
 138                 if [ "${dtx_arch}" != ""  -a "${dtx_arch}" != "${ARCH}" ] ; then
 139                         hint_given=1
 140                         echo ""                                              >&2
 141                         echo "  architecture ${dtx_arch} is in file path,"   >&2
 142                         echo "  but does not match shell variable \$ARCH"    >&2
 143                         echo "  >>\$ARCH<< is: >>${ARCH}<<"                  >&2
 144                 fi
 145
 146                 if [ ! -d ${srctree}/arch/${ARCH} ] ; then
 147                         hint_given=1
 148                         echo ""                                              >&2
 149                         echo "  ${srctree}/arch/${ARCH}/ does not exist"     >&2
 150                         echo "  Is \$ARCH='${ARCH}' correct?"                >&2
 151                         echo "  Possible fix: use '-s' option"               >&2
 152
 153                         git_root=`git rev-parse --show-toplevel 2>/dev/null`
 154                         if [ -d ${git_root}/arch/ ] ; then
 155                                 echo "  Possible fix: use '-S' option"       >&2
 156                         fi
 157                 fi
 158
 159                 if [ $hint_given = 0 ] ; then
 160                         echo ""                                              >&2
 161                         echo "  No hints available."                         >&2
 162                 fi
 163
 164                 echo ""                                                      >&2
 165
 166                 exit 3
 167
 168         else
 169                 echo ""                                                     >&2
 170                 echo "ERROR: ${dtx} does not exist or is not readable"      >&2
 171                 echo ""                                                     >&2
 172                 exit 2
 173         fi
 174
 175 }
 176
 177
 178 # -----  start of script
 179
 180 annotate=""
 181 cmd_diff=0
 182 diff_flags="-u"
 183 diff_color=""
 184 dtx_file_1=""
 185 dtx_file_2=""
 186 dtc_sort="-s"
 187 help=0
 188 srctree=""
 189
 190
 191 while [ $# -gt 0 ] ; do
 192
 193         case $1 in
 194
 195         -c | --color )
 196                 if diff --color /dev/null /dev/null 2>/dev/null ; then
 197                         diff_color="--color=always"
 198                 fi
 199                 shift
 200                 ;;
 201
 202         -f )
 203                 diff_flags="--unified=999999"
 204                 shift
 205                 ;;
 206
 207         -h | -help | --help )
 208                 help=1
 209                 shift
 210                 ;;
 211
 212         -s )
 213                 srctree="$2"
 214                 shift 2
 215                 ;;
 216
 217         -S )
 218                 git_root=`git rev-parse --show-toplevel 2>/dev/null`
 219                 srctree="${git_root}"
 220                 shift
 221                 ;;
 222
 223         -T | --annotate )
 224                 if [ "${annotate}"  = "" ] ; then
 225                         annotate="-T"
 226                 elif [ "${annotate}"  = "-T" ] ; then
 227                         annotate="-T -T"
 228                 fi
 229                 shift
 230                 ;;
 231         -u )
 232                 dtc_sort=""
 233                 shift
 234                 ;;
 235
 236         *)
 237                 if [ "${dtx_file_1}"  = "" ] ; then
 238                         dtx_file_1="$1"
 239                 elif [ "${dtx_file_2}" = "" ] ; then
 240                         dtx_file_2="$1"
 241                 else
 242                         echo ""                                             >&2
 243                         echo "ERROR: Unexpected parameter: $1"              >&2
 244                         echo ""                                             >&2
 245                         exit 2
 246                 fi
 247                 shift
 248                 ;;
 249
 250         esac
 251
 252 done
 253
 254 if [ "${srctree}" = "" ] ; then
 255         srctree="."
 256 fi
 257
 258 if [ "${dtx_file_2}" != "" ]; then
 259         cmd_diff=1
 260 fi
 261
 262 if (( ${help} )) ; then
 263         usage
 264         exit 1
 265 fi
 266
 267 # this must follow check for ${help}
 268 if [ "${dtx_file_1}" = "" ]; then
 269         echo ""                                                             >&2
 270         echo "ERROR: parameter DTx required"                                >&2
 271         echo ""                                                             >&2
 272         exit 2
 273 fi
 274
 275
 276 # -----  prefer dtc from linux kernel, allow fallback to dtc in $PATH
 277
 278 if [ "${KBUILD_OUTPUT:0:2}" = ".." ] ; then
 279         __KBUILD_OUTPUT="${srctree}/${KBUILD_OUTPUT}"
 280 elif [ "${KBUILD_OUTPUT}" = "" ] ; then
 281         __KBUILD_OUTPUT="."
 282 else
 283         __KBUILD_OUTPUT="${KBUILD_OUTPUT}"
 284 fi
 285
 286 DTC="${__KBUILD_OUTPUT}/scripts/dtc/dtc"
 287
 288 if [ ! -x ${DTC} ] ; then
 289         __DTC="dtc"
 290         if grep -q "^CONFIG_DTC=y" ${__KBUILD_OUTPUT}/.config 2>/dev/null; then
 291                 make_command='
 292          make scripts'
 293         else
 294                 make_command='
 295          Enable CONFIG_DTC in the kernel configuration
 296          make scripts'
 297         fi
 298         if ( ! which ${__DTC} >/dev/null ) ; then
 299
 300                 # use spaces instead of tabs in the error message
 301                 cat >&2 <<eod
 302
 303 ERROR: unable to find a 'dtc' program
 304
 305    Preferred 'dtc' (built from Linux kernel source tree) was not found or
 306    is not executable.
 307
 308       'dtc' is: ${DTC}
 309
 310       If it does not exist, create it from the root of the Linux source tree:
 311 ${make_command}
 312
 313       If not at the root of the Linux kernel source tree -s SRCTREE or -S
 314       may need to be specified to find 'dtc'.
 315
 316       If 'O=\${dir}' is specified in your Linux builds, this script requires
 317       'export KBUILD_OUTPUT=\${dir}' or add \${dir}/scripts/dtc to \$PATH
 318       before running.
 319
 320       If \${KBUILD_OUTPUT} is a relative path, then '-s SRCDIR', -S, or run
 321       this script from the root of the Linux kernel source tree is required.
 322
 323    Fallback '${__DTC}' was also not in \${PATH} or is not executable.
 324
 325 eod
 326                 exit 2
 327         fi
 328         DTC=${__DTC}
 329 fi
 330
 331
 332 # -----  cpp and dtc flags same as for linux source tree build of .dtb files,
 333 #        plus directories of the dtx file(s)
 334
 335 dtx_path_1_dtc_include="-i `dirname ${dtx_file_1}`"
 336
 337 dtx_path_2_dtc_include=""
 338 if (( ${cmd_diff} )) ; then
 339         dtx_path_2_dtc_include="-i `dirname ${dtx_file_2}`"
 340 fi
 341
 342 cpp_flags="\
 343         -nostdinc                                  \
 344         -I${srctree}/scripts/dtc/include-prefixes  \
 345         -undef -D__DTS__"
 346
 347 DTC="\
 348         ${DTC}                                     \
 349         -i ${srctree}/scripts/dtc/include-prefixes \
 350         -O dts -qq -f ${dtc_sort} ${annotate} -o -"
 351
 352
 353 # -----  do the diff or decompile
 354
 355 if (( ${cmd_diff} )) ; then
 356
 357         diff ${diff_flags} ${diff_color} --label "${dtx_file_1}" --label "${dtx_file_2}" \
 358                 <(compile_to_dts "${dtx_file_1}" "${dtx_path_1_dtc_include}") \
 359                 <(compile_to_dts "${dtx_file_2}" "${dtx_path_2_dtc_include}")
 360
 361 else
 362
 363         compile_to_dts "${dtx_file_1}" "${dtx_path_1_dtc_include}"
 364
 365 fi