xref: /linux/scripts/dtc/dtx_diff (revision 4eb7ae7a301d3586c3351e81d5c3cfe2304a1a6a)
1#! /bin/bash
2# SPDX-License-Identifier: GPL-2.0-only
3
4# Copyright (C) 2015 Frank Rowand
5#
6
7
8usage() {
9
10	# use spaces instead of tabs in the usage message
11	cat >&2 <<eod
12
13Usage:
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
36Each DTx is processed by the dtc compiler to produce a sorted dts source
37file.  If DTx is a dts source file then it is pre-processed in the same
38manner as done for the compile of the dts source file in the Linux kernel
39build system ('#include' and '/include/' directives are processed).
40
41If two DTx are provided, the resulting dts source files are diffed.
42
43If DTx is a directory, it is treated as a DT subtree, such as
44  /proc/device-tree.
45
46If 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
49Otherwise 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
84eod
85}
86
87
88compile_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
179annotate=""
180cmd_diff=0
181diff_flags="-u"
182diff_color=""
183dtx_file_1=""
184dtx_file_2=""
185dtc_sort="-s"
186help=0
187srctree=""
188
189
190while [ $# -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: $1"              >&2
243			echo ""                                             >&2
244			exit 2
245		fi
246		shift
247		;;
248
249	esac
250
251done
252
253if [ "${srctree}" = "" ] ; then
254	srctree="."
255fi
256
257if [ "${dtx_file_2}" != "" ]; then
258	cmd_diff=1
259fi
260
261if (( ${help} )) ; then
262	usage
263	exit 1
264fi
265
266# this must follow check for ${help}
267if [ "${dtx_file_1}" = "" ]; then
268	echo ""                                                             >&2
269	echo "ERROR: parameter DTx required"                                >&2
270	echo ""                                                             >&2
271	exit 2
272fi
273
274
275# -----  prefer dtc from linux kernel, allow fallback to dtc in $PATH
276
277if [ "${KBUILD_OUTPUT:0:2}" = ".." ] ; then
278	__KBUILD_OUTPUT="${srctree}/${KBUILD_OUTPUT}"
279elif [ "${KBUILD_OUTPUT}" = "" ] ; then
280	__KBUILD_OUTPUT="."
281else
282	__KBUILD_OUTPUT="${KBUILD_OUTPUT}"
283fi
284
285DTC="${__KBUILD_OUTPUT}/scripts/dtc/dtc"
286
287if [ ! -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
302ERROR: 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 '${__DTC}' was also not in \${PATH} or is not executable.
323
324eod
325		exit 2
326	fi
327	DTC=${__DTC}
328fi
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
334dtx_path_1_dtc_include="-i `dirname ${dtx_file_1}`"
335
336dtx_path_2_dtc_include=""
337if (( ${cmd_diff} )) ; then
338	dtx_path_2_dtc_include="-i `dirname ${dtx_file_2}`"
339fi
340
341cpp_flags="\
342	-nostdinc                                  \
343	-I${srctree}/scripts/dtc/include-prefixes  \
344	-undef -D__DTS__"
345
346DTC="\
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
354if (( ${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}" "${dtx_path_2_dtc_include}")
359
360else
361
362	compile_to_dts "${dtx_file_1}" "${dtx_path_1_dtc_include}"
363
364fi
365