scripts/dtc/dtx_diff

   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         dtc_include="$2"
  90
  91         if [ -d "${dtx}" ] ; then
  92
  93                 # -----  input is file tree
  94
  95                 if ( ! ${DTC} -I fs ${dtx} ) ; then
  96                         exit 3
  97                 fi
  98
  99         elif [ -f "${dtx}" ] && [ -r "${dtx}" ] ; then
 100
 101                 magic=`hexdump -n 4 -e '/1 "%02x"' ${dtx}`
 102                 if [ "${magic}" = "d00dfeed" ] ; then
 103
 104                         # -----  input is FDT (binary blob)
 105
 106                         if ( ! ${DTC} -I dtb ${dtx} ) ; then
 107                                 exit 3
 108                         fi
 109
 110                         return
 111
 112                 fi
 113
 114                 # -----  input is DTS (source)
 115
 116                 if ( cpp ${cpp_flags} -x assembler-with-cpp ${dtx} \
 117                         | ${DTC} ${dtc_include} -I dts ) ; then
 118                         return
 119                 fi
 120
 121                 echo ""                                                      >&2
 122                 echo "Possible hints to resolve the above error:"            >&2
 123                 echo "  (hints might not fix the problem)"                   >&2
 124
 125                 hint_given=0
 126
 127                 if [ "${ARCH}" = "" ] ; then
 128                         hint_given=1
 129                         echo ""                                              >&2
 130                         echo "  shell variable \$ARCH not set"               >&2
 131                 fi
 132
 133                 dtx_arch=`echo "/${dtx}" | sed -e 's|.*/arch/||' -e 's|/.*||'`
 134
 135                 if [ "${dtx_arch}" != ""  -a "${dtx_arch}" != "${ARCH}" ] ; then
 136                         hint_given=1
 137                         echo ""                                              >&2
 138                         echo "  architecture ${dtx_arch} is in file path,"   >&2
 139                         echo "  but does not match shell variable \$ARCH"    >&2
 140                         echo "  >>\$ARCH<< is: >>${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 grep -q "^CONFIG_DTC=y" ${__KBUILD_OUTPUT}/.config 2>/dev/null; then
 271                 make_command='
 272          make scripts'
 273         else
 274                 make_command='
 275          Enable CONFIG_DTC in the kernel configuration
 276          make scripts'
 277         fi
 278         if ( ! which ${__DTC} >/dev/null ) ; then
 279
 280                 # use spaces instead of tabs in the error message
 281                 cat >&2 <<eod
 282
 283 ERROR: unable to find a 'dtc' program
 284
 285    Preferred 'dtc' (built from Linux kernel source tree) was not found or
 286    is not executable.
 287
 288       'dtc' is: ${DTC}
 289
 290       If it does not exist, create it from the root of the Linux source tree:
 291 ${make_command}
 292
 293       If not at the root of the Linux kernel source tree -s SRCTREE or -S
 294       may need to be specified to find 'dtc'.
 295
 296       If 'O=\${dir}' is specified in your Linux builds, this script requires
 297       'export KBUILD_OUTPUT=\${dir}' or add \${dir}/scripts/dtc to \$PATH
 298       before running.
 299
 300       If \${KBUILD_OUTPUT} is a relative path, then '-s SRCDIR', -S, or run
 301       this script from the root of the Linux kernel source tree is required.
 302
 303    Fallback '${__DTC}' was also not in \${PATH} or is not executable.
 304
 305 eod
 306                 exit 2
 307         fi
 308         DTC=${__DTC}
 309 fi
 310
 311
 312 # -----  cpp and dtc flags same as for linux source tree build of .dtb files,
 313 #        plus directories of the dtx file(s)
 314
 315 dtx_path_1_dtc_include="-i `dirname ${dtx_file_1}`"
 316
 317 dtx_path_2_dtc_include=""
 318 if (( ${cmd_diff} )) ; then
 319         dtx_path_2_dtc_include="-i `dirname ${dtx_file_2}`"
 320 fi
 321
 322 cpp_flags="\
 323         -nostdinc                                  \
 324         -I${srctree}/scripts/dtc/include-prefixes  \
 325         -undef -D__DTS__"
 326
 327 DTC="\
 328         ${DTC}                                     \
 329         -i ${srctree}/scripts/dtc/include-prefixes \
 330         -O dts -qq -f ${dtc_sort} -o -"
 331
 332
 333 # -----  do the diff or decompile
 334
 335 if (( ${cmd_diff} )) ; then
 336
 337         diff ${diff_flags} --label "${dtx_file_1}" --label "${dtx_file_2}" \
 338                 <(compile_to_dts "${dtx_file_1}" "${dtx_path_1_dtc_include}") \
 339                 <(compile_to_dts "${dtx_file_2}" "${dtx_path_2_dtc_include}")
 340
 341 else
 342
 343         compile_to_dts "${dtx_file_1}" "${dtx_path_1_dtc_include}"
 344
 345 fi