xref: /openbmc/linux/scripts/dtc/dtx_diff (revision 51bc620b) 
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       -f           print full dts in diff (--unified=99999)
24       -h           synonym for --help
25       -help        synonym for --help
26      --help        print this message and exit
27       -s SRCTREE   linux kernel source tree is at path SRCTREE
28                        (default is current directory)
29       -S           linux kernel source tree is at root of current git repo
30       -T           Annotate output .dts with input source file and line (-T -T for more details)
31       -u           unsorted, do not sort DTx
32
33
34Each DTx is processed by the dtc compiler to produce a sorted dts source
35file.  If DTx is a dts source file then it is pre-processed in the same
36manner as done for the compile of the dts source file in the Linux kernel
37build system ('#include' and '/include/' directives are processed).
38
39If two DTx are provided, the resulting dts source files are diffed.
40
41If DTx is a directory, it is treated as a DT subtree, such as
42  /proc/device-tree.
43
44If 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
47Otherwise 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
82eod
83}
84
85
86compile_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
177annotate=""
178cmd_diff=0
179diff_flags="-u"
180dtx_file_1=""
181dtx_file_2=""
182dtc_sort="-s"
183help=0
184srctree=""
185
186
187while [ $# -gt 0 ] ; do
188
189	case $1 in
190
191	-f )
192		diff_flags="--unified=999999"
193		shift
194		;;
195
196	-h | -help | --help )
197		help=1
198		shift
199		;;
200
201	-s )
202		srctree="$2"
203		shift 2
204		;;
205
206	-S )
207		git_root=`git rev-parse --show-toplevel 2>/dev/null`
208		srctree="${git_root}"
209		shift
210		;;
211
212	-T | --annotate )
213		if [ "${annotate}"  = "" ] ; then
214			annotate="-T"
215		elif [ "${annotate}"  = "-T" ] ; then
216			annotate="-T -T"
217		fi
218		shift
219		;;
220	-u )
221		dtc_sort=""
222		shift
223		;;
224
225	*)
226		if [ "${dtx_file_1}"  = "" ] ; then
227			dtx_file_1="$1"
228		elif [ "${dtx_file_2}" = "" ] ; then
229			dtx_file_2="$1"
230		else
231			echo ""                                             >&2
232			echo "ERROR: Unexpected parameter: $1"              >&2
233			echo ""                                             >&2
234			exit 2
235		fi
236		shift
237		;;
238
239	esac
240
241done
242
243if [ "${srctree}" = "" ] ; then
244	srctree="."
245fi
246
247if [ "${dtx_file_2}" != "" ]; then
248	cmd_diff=1
249fi
250
251if (( ${help} )) ; then
252	usage
253	exit 1
254fi
255
256# this must follow check for ${help}
257if [ "${dtx_file_1}" = "" ]; then
258	echo ""                                                             >&2
259	echo "ERROR: parameter DTx required"                                >&2
260	echo ""                                                             >&2
261	exit 2
262fi
263
264
265# -----  prefer dtc from linux kernel, allow fallback to dtc in $PATH
266
267if [ "${KBUILD_OUTPUT:0:2}" = ".." ] ; then
268	__KBUILD_OUTPUT="${srctree}/${KBUILD_OUTPUT}"
269elif [ "${KBUILD_OUTPUT}" = "" ] ; then
270	__KBUILD_OUTPUT="."
271else
272	__KBUILD_OUTPUT="${KBUILD_OUTPUT}"
273fi
274
275DTC="${__KBUILD_OUTPUT}/scripts/dtc/dtc"
276
277if [ ! -x ${DTC} ] ; then
278	__DTC="dtc"
279	if grep -q "^CONFIG_DTC=y" ${__KBUILD_OUTPUT}/.config 2>/dev/null; then
280		make_command='
281         make scripts'
282	else
283		make_command='
284         Enable CONFIG_DTC in the kernel configuration
285         make scripts'
286	fi
287	if ( ! which ${__DTC} >/dev/null ) ; then
288
289		# use spaces instead of tabs in the error message
290		cat >&2 <<eod
291
292ERROR: unable to find a 'dtc' program
293
294   Preferred 'dtc' (built from Linux kernel source tree) was not found or
295   is not executable.
296
297      'dtc' is: ${DTC}
298
299      If it does not exist, create it from the root of the Linux source tree:
300${make_command}
301
302      If not at the root of the Linux kernel source tree -s SRCTREE or -S
303      may need to be specified to find 'dtc'.
304
305      If 'O=\${dir}' is specified in your Linux builds, this script requires
306      'export KBUILD_OUTPUT=\${dir}' or add \${dir}/scripts/dtc to \$PATH
307      before running.
308
309      If \${KBUILD_OUTPUT} is a relative path, then '-s SRCDIR', -S, or run
310      this script from the root of the Linux kernel source tree is required.
311
312   Fallback '${__DTC}' was also not in \${PATH} or is not executable.
313
314eod
315		exit 2
316	fi
317	DTC=${__DTC}
318fi
319
320
321# -----  cpp and dtc flags same as for linux source tree build of .dtb files,
322#        plus directories of the dtx file(s)
323
324dtx_path_1_dtc_include="-i `dirname ${dtx_file_1}`"
325
326dtx_path_2_dtc_include=""
327if (( ${cmd_diff} )) ; then
328	dtx_path_2_dtc_include="-i `dirname ${dtx_file_2}`"
329fi
330
331cpp_flags="\
332	-nostdinc                                  \
333	-I${srctree}/scripts/dtc/include-prefixes  \
334	-undef -D__DTS__"
335
336DTC="\
337	${DTC}                                     \
338	-i ${srctree}/scripts/dtc/include-prefixes \
339	-O dts -qq -f ${dtc_sort} ${annotate} -o -"
340
341
342# -----  do the diff or decompile
343
344if (( ${cmd_diff} )) ; then
345
346	diff ${diff_flags} --label "${dtx_file_1}" --label "${dtx_file_2}" \
347		<(compile_to_dts "${dtx_file_1}" "${dtx_path_1_dtc_include}") \
348		<(compile_to_dts "${dtx_file_2}" "${dtx_path_2_dtc_include}")
349
350else
351
352	compile_to_dts "${dtx_file_1}" "${dtx_path_1_dtc_include}"
353
354fi
355