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="$1"
  89
  90         if [ -d "${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 ${dtx_arch} is in file path,"   >&2
 138                         echo "  but does not match shell variable \$ARCH"    >&2
 139                         echo "  >>\$ARCH<< is: >>${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 cmd_diff=0
 177 diff_flags="-u"
 178 dtx_file_1=""
 179 dtx_file_2=""
 180 dtc_sort="-s"
 181 help=0
 182 srctree=""
 183
 184
 185 while [ $# -gt 0 ] ; do
 186
 187         case $1 in
 188
 189         -f )
 190                 diff_flags="--unified=999999"
 191                 shift
 192                 ;;
 193
 194         -h | -help | --help )
 195                 help=1
 196                 shift
 197                 ;;
 198
 199         -s )
 200                 srctree="$2"
 201                 shift 2
 202                 ;;
 203
 204         -S )
 205                 git_root=`git rev-parse --show-toplevel 2>/dev/null`
 206                 srctree="${git_root}"
 207                 shift
 208                 ;;
 209
 210         -u )
 211                 dtc_sort=""
 212                 shift
 213                 ;;
 214
 215         *)
 216                 if [ "${dtx_file_1}"  = "" ] ; then
 217                         dtx_file_1="$1"
 218                 elif [ "${dtx_file_2}" = "" ] ; then
 219                         dtx_file_2="$1"
 220                 else
 221                         echo ""                                             >&2
 222                         echo "ERROR: Unexpected parameter: $1"              >&2
 223                         echo ""                                             >&2
 224                         exit 2
 225                 fi
 226                 shift
 227                 ;;
 228
 229         esac
 230
 231 done
 232
 233 if [ "${srctree}" = "" ] ; then
 234         srctree="."
 235 fi
 236
 237 if [ "${dtx_file_2}" != "" ]; then
 238         cmd_diff=1
 239 fi
 240
 241 if (( ${help} )) ; then
 242         usage
 243         exit 1
 244 fi
 245
 246 # this must follow check for ${help}
 247 if [ "${dtx_file_1}" = "" ]; then
 248         echo ""                                                             >&2
 249         echo "ERROR: parameter DTx required"                                >&2
 250         echo ""                                                             >&2
 251         exit 2
 252 fi
 253
 254
 255 # -----  prefer dtc from linux kernel, allow fallback to dtc in $PATH
 256
 257 if [ "${KBUILD_OUTPUT:0:2}" = ".." ] ; then
 258         __KBUILD_OUTPUT="${srctree}/${KBUILD_OUTPUT}"
 259 elif [ "${KBUILD_OUTPUT}" = "" ] ; then
 260         __KBUILD_OUTPUT="."
 261 else
 262         __KBUILD_OUTPUT="${KBUILD_OUTPUT}"
 263 fi
 264
 265 DTC="${__KBUILD_OUTPUT}/scripts/dtc/dtc"
 266
 267 if [ ! -x ${DTC} ] ; then
 268         __DTC="dtc"
 269         if grep -q "^CONFIG_DTC=y" ${__KBUILD_OUTPUT}/.config ; then
 270                 make_command='
 271          make scripts'
 272         else
 273                 make_command='
 274          Enable CONFIG_DTC in the kernel configuration
 275          make scripts'
 276         fi
 277         if ( ! which ${__DTC} >/dev/null ) ; then
 278
 279                 # use spaces instead of tabs in the error message
 280                 cat >&2 <<eod
 281
 282 ERROR: unable to find a 'dtc' program
 283
 284    Preferred 'dtc' (built from Linux kernel source tree) was not found or
 285    is not executable.
 286
 287       'dtc' is: ${DTC}
 288
 289       If it does not exist, create it from the root of the Linux source tree:
 290 ${make_command}
 291
 292       If not at the root of the Linux kernel source tree -s SRCTREE or -S
 293       may need to be specified to find 'dtc'.
 294
 295       If 'O=\${dir}' is specified in your Linux builds, this script requires
 296       'export KBUILD_OUTPUT=\${dir}' or add \${dir}/scripts/dtc to \$PATH
 297       before running.
 298
 299       If \${KBUILD_OUTPUT} is a relative path, then '-s SRCDIR', -S, or run
 300       this script from the root of the Linux kernel source tree is required.
 301
 302    Fallback '${__DTC}' was also not in \${PATH} or is not executable.
 303
 304 eod
 305                 exit 2
 306         fi
 307         DTC=${__DTC}
 308 fi
 309
 310
 311 # -----  cpp and dtc flags same as for linux source tree build of .dtb files,
 312 #        plus directories of the dtx file(s)
 313
 314 dtx_path_1_dtc_include="-i `dirname ${dtx_file_1}`"
 315
 316 dtx_path_2_dtc_include=""
 317 if (( ${cmd_diff} )) ; then
 318         dtx_path_2_dtc_include="-i `dirname ${dtx_file_2}`"
 319 fi
 320
 321 cpp_flags="\
 322         -nostdinc                                  \
 323         -I${srctree}/arch/${ARCH}/boot/dts         \
 324         -I${srctree}/arch/${ARCH}/boot/dts/include \
 325         -I${srctree}/drivers/of/testcase-data      \
 326         -undef -D__DTS__"
 327
 328 dtc_flags="\
 329         -i ${srctree}/arch/${ARCH}/boot/dts/ \
 330         -i ${srctree}/kernel/dts             \
 331         ${dtx_path_1_dtc_include}            \
 332         ${dtx_path_2_dtc_include}"
 333
 334 DTC="${DTC} ${dtc_flags} -O dts -qq -f ${dtc_sort} -o -"
 335
 336
 337 # -----  do the diff or decompile
 338
 339 if (( ${cmd_diff} )) ; then
 340
 341         diff ${diff_flags} \
 342                 <(compile_to_dts "${dtx_file_1}") \
 343                 <(compile_to_dts "${dtx_file_2}")
 344
 345 else
 346
 347         compile_to_dts "${dtx_file_1}"
 348
 349 fi