xref: /openbmc/linux/scripts/dtc/dtx_diff (revision 3381df09)
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 (-T -T for more details)
33        -u           unsorted, do not sort DTx
34 
35 
36 Each DTx is processed by the dtc compiler to produce a sorted dts source
37 file.  If DTx is a dts source file then it is pre-processed in the same
38 manner as done for the compile of the dts source file in the Linux kernel
39 build system ('#include' and '/include/' directives are processed).
40 
41 If two DTx are provided, the resulting dts source files are diffed.
42 
43 If DTx is a directory, it is treated as a DT subtree, such as
44   /proc/device-tree.
45 
46 If DTx contains the binary blob magic value in the first four bytes,
47   it is treated as a binary blob (aka .dtb or FDT).
48 
49 Otherwise DTx is treated as a dts source file (aka .dts).
50 
51    If this script is not run from the root of the linux source tree,
52    and DTx utilizes '#include' or '/include/' then the path of the
53    linux source tree can be provided by '-s SRCTREE' or '-S' so that
54    include paths will be set properly.
55 
56    The shell variable \${ARCH} must provide the architecture containing
57    the dts source file for include paths to be set properly for '#include'
58    or '/include/' to be processed.
59 
60    If DTx_1 and DTx_2 are in different architectures, then this script
61    may not work since \${ARCH} is part of the include path.  Two possible
62    workarounds:
63 
64       `basename $0` \\
65           <(ARCH=arch_of_dtx_1 `basename $0` DTx_1) \\
66           <(ARCH=arch_of_dtx_2 `basename $0` DTx_2)
67 
68       `basename $0` ARCH=arch_of_dtx_1 DTx_1 >tmp_dtx_1.dts
69       `basename $0` ARCH=arch_of_dtx_2 DTx_2 >tmp_dtx_2.dts
70       `basename $0` tmp_dtx_1.dts tmp_dtx_2.dts
71       rm tmp_dtx_1.dts tmp_dtx_2.dts
72 
73    If DTx_1 and DTx_2 are in different directories, then this script will
74    add the path of DTx_1 and DTx_2 to the include paths.  If DTx_2 includes
75    a local file that exists in both the path of DTx_1 and DTx_2 then the
76    file in the path of DTx_1 will incorrectly be included.  Possible
77    workaround:
78 
79       `basename $0` DTx_1 >tmp_dtx_1.dts
80       `basename $0` DTx_2 >tmp_dtx_2.dts
81       `basename $0` tmp_dtx_1.dts tmp_dtx_2.dts
82       rm tmp_dtx_1.dts tmp_dtx_2.dts
83 
84 eod
85 }
86 
87 
88 compile_to_dts() {
89 
90 	dtx="$1"
91 	dtc_include="$2"
92 
93 	if [ -d "${dtx}" ] ; then
94 
95 		# -----  input is file tree
96 
97 		if ( ! ${DTC} -I fs ${dtx} ) ; then
98 			exit 3
99 		fi
100 
101 	elif [ -f "${dtx}" ] && [ -r "${dtx}" ] ; then
102 
103 		magic=`hexdump -n 4 -e '/1 "%02x"' ${dtx}`
104 		if [ "${magic}" = "d00dfeed" ] ; then
105 
106 			# -----  input is FDT (binary blob)
107 
108 			if ( ! ${DTC} -I dtb ${dtx} ) ; then
109 				exit 3
110 			fi
111 
112 			return
113 
114 		fi
115 
116 		# -----  input is DTS (source)
117 
118 		if ( cpp ${cpp_flags} -x assembler-with-cpp ${dtx} \
119 			| ${DTC} ${dtc_include} -I dts ) ; then
120 			return
121 		fi
122 
123 		echo ""                                                      >&2
124 		echo "Possible hints to resolve the above error:"            >&2
125 		echo "  (hints might not fix the problem)"                   >&2
126 
127 		hint_given=0
128 
129 		if [ "${ARCH}" = "" ] ; then
130 			hint_given=1
131 			echo ""                                              >&2
132 			echo "  shell variable \$ARCH not set"               >&2
133 		fi
134 
135 		dtx_arch=`echo "/${dtx}" | sed -e 's|.*/arch/||' -e 's|/.*||'`
136 
137 		if [ "${dtx_arch}" != ""  -a "${dtx_arch}" != "${ARCH}" ] ; then
138 			hint_given=1
139 			echo ""                                              >&2
140 			echo "  architecture ${dtx_arch} is in file path,"   >&2
141 			echo "  but does not match shell variable \$ARCH"    >&2
142 			echo "  >>\$ARCH<< is: >>${ARCH}<<"                  >&2
143 		fi
144 
145 		if [ ! -d ${srctree}/arch/${ARCH} ] ; then
146 			hint_given=1
147 			echo ""                                              >&2
148 			echo "  ${srctree}/arch/${ARCH}/ does not exist"     >&2
149 			echo "  Is \$ARCH='${ARCH}' correct?"                >&2
150 			echo "  Possible fix: use '-s' option"               >&2
151 
152 			git_root=`git rev-parse --show-toplevel 2>/dev/null`
153 			if [ -d ${git_root}/arch/ ] ; then
154 				echo "  Possible fix: use '-S' option"       >&2
155 			fi
156 		fi
157 
158 		if [ $hint_given = 0 ] ; then
159 			echo ""                                              >&2
160 			echo "  No hints available."                         >&2
161 		fi
162 
163 		echo ""                                                      >&2
164 
165 		exit 3
166 
167 	else
168 		echo ""                                                     >&2
169 		echo "ERROR: ${dtx} does not exist or is not readable"      >&2
170 		echo ""                                                     >&2
171 		exit 2
172 	fi
173 
174 }
175 
176 
177 # -----  start of script
178 
179 annotate=""
180 cmd_diff=0
181 diff_flags="-u"
182 diff_color=""
183 dtx_file_1=""
184 dtx_file_2=""
185 dtc_sort="-s"
186 help=0
187 srctree=""
188 
189 
190 while [ $# -gt 0 ] ; do
191 
192 	case $1 in
193 
194 	-c | --color )
195 		if diff --color /dev/null /dev/null 2>/dev/null ; then
196 			diff_color="--color=always"
197 		fi
198 		shift
199 		;;
200 
201 	-f )
202 		diff_flags="--unified=999999"
203 		shift
204 		;;
205 
206 	-h | -help | --help )
207 		help=1
208 		shift
209 		;;
210 
211 	-s )
212 		srctree="$2"
213 		shift 2
214 		;;
215 
216 	-S )
217 		git_root=`git rev-parse --show-toplevel 2>/dev/null`
218 		srctree="${git_root}"
219 		shift
220 		;;
221 
222 	-T | --annotate )
223 		if [ "${annotate}"  = "" ] ; then
224 			annotate="-T"
225 		elif [ "${annotate}"  = "-T" ] ; then
226 			annotate="-T -T"
227 		fi
228 		shift
229 		;;
230 	-u )
231 		dtc_sort=""
232 		shift
233 		;;
234 
235 	*)
236 		if [ "${dtx_file_1}"  = "" ] ; then
237 			dtx_file_1="$1"
238 		elif [ "${dtx_file_2}" = "" ] ; then
239 			dtx_file_2="$1"
240 		else
241 			echo ""                                             >&2
242 			echo "ERROR: Unexpected parameter: $1"              >&2
243 			echo ""                                             >&2
244 			exit 2
245 		fi
246 		shift
247 		;;
248 
249 	esac
250 
251 done
252 
253 if [ "${srctree}" = "" ] ; then
254 	srctree="."
255 fi
256 
257 if [ "${dtx_file_2}" != "" ]; then
258 	cmd_diff=1
259 fi
260 
261 if (( ${help} )) ; then
262 	usage
263 	exit 1
264 fi
265 
266 # this must follow check for ${help}
267 if [ "${dtx_file_1}" = "" ]; then
268 	echo ""                                                             >&2
269 	echo "ERROR: parameter DTx required"                                >&2
270 	echo ""                                                             >&2
271 	exit 2
272 fi
273 
274 
275 # -----  prefer dtc from linux kernel, allow fallback to dtc in $PATH
276 
277 if [ "${KBUILD_OUTPUT:0:2}" = ".." ] ; then
278 	__KBUILD_OUTPUT="${srctree}/${KBUILD_OUTPUT}"
279 elif [ "${KBUILD_OUTPUT}" = "" ] ; then
280 	__KBUILD_OUTPUT="."
281 else
282 	__KBUILD_OUTPUT="${KBUILD_OUTPUT}"
283 fi
284 
285 DTC="${__KBUILD_OUTPUT}/scripts/dtc/dtc"
286 
287 if [ ! -x ${DTC} ] ; then
288 	__DTC="dtc"
289 	if grep -q "^CONFIG_DTC=y" ${__KBUILD_OUTPUT}/.config 2>/dev/null; then
290 		make_command='
291          make scripts'
292 	else
293 		make_command='
294          Enable CONFIG_DTC in the kernel configuration
295          make scripts'
296 	fi
297 	if ( ! which ${__DTC} >/dev/null ) ; then
298 
299 		# use spaces instead of tabs in the error message
300 		cat >&2 <<eod
301 
302 ERROR: unable to find a 'dtc' program
303 
304    Preferred 'dtc' (built from Linux kernel source tree) was not found or
305    is not executable.
306 
307       'dtc' is: ${DTC}
308 
309       If it does not exist, create it from the root of the Linux source tree:
310 ${make_command}
311 
312       If not at the root of the Linux kernel source tree -s SRCTREE or -S
313       may need to be specified to find 'dtc'.
314 
315       If 'O=\${dir}' is specified in your Linux builds, this script requires
316       'export KBUILD_OUTPUT=\${dir}' or add \${dir}/scripts/dtc to \$PATH
317       before running.
318 
319       If \${KBUILD_OUTPUT} is a relative path, then '-s SRCDIR', -S, or run
320       this script from the root of the Linux kernel source tree is required.
321 
322    Fallback '${__DTC}' was also not in \${PATH} or is not executable.
323 
324 eod
325 		exit 2
326 	fi
327 	DTC=${__DTC}
328 fi
329 
330 
331 # -----  cpp and dtc flags same as for linux source tree build of .dtb files,
332 #        plus directories of the dtx file(s)
333 
334 dtx_path_1_dtc_include="-i `dirname ${dtx_file_1}`"
335 
336 dtx_path_2_dtc_include=""
337 if (( ${cmd_diff} )) ; then
338 	dtx_path_2_dtc_include="-i `dirname ${dtx_file_2}`"
339 fi
340 
341 cpp_flags="\
342 	-nostdinc                                  \
343 	-I${srctree}/scripts/dtc/include-prefixes  \
344 	-undef -D__DTS__"
345 
346 DTC="\
347 	${DTC}                                     \
348 	-i ${srctree}/scripts/dtc/include-prefixes \
349 	-O dts -qq -f ${dtc_sort} ${annotate} -o -"
350 
351 
352 # -----  do the diff or decompile
353 
354 if (( ${cmd_diff} )) ; then
355 
356 	diff ${diff_flags} ${diff_color} --label "${dtx_file_1}" --label "${dtx_file_2}" \
357 		<(compile_to_dts "${dtx_file_1}" "${dtx_path_1_dtc_include}") \
358 		<(compile_to_dts "${dtx_file_2}" "${dtx_path_2_dtc_include}")
359 
360 else
361 
362 	compile_to_dts "${dtx_file_1}" "${dtx_path_1_dtc_include}"
363 
364 fi
365