xref: /linux/scripts/dtc/dtx_diff (revision 74ce1896c6c65b2f8cccbf59162d542988835835)
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
10usage() {
11
12	# use spaces instead of tabs in the usage message
13	cat >&2 <<eod
14
15Usage:
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
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="$1"
89
90	if [ -d "${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
176cmd_diff=0
177diff_flags="-u"
178dtx_file_1=""
179dtx_file_2=""
180dtc_sort="-s"
181help=0
182srctree=""
183
184
185while [ $# -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: $1"              >&2
223			echo ""                                             >&2
224			exit 2
225		fi
226		shift
227		;;
228
229	esac
230
231done
232
233if [ "${srctree}" = "" ] ; then
234	srctree="."
235fi
236
237if [ "${dtx_file_2}" != "" ]; then
238	cmd_diff=1
239fi
240
241if (( ${help} )) ; then
242	usage
243	exit 1
244fi
245
246# this must follow check for ${help}
247if [ "${dtx_file_1}" = "" ]; then
248	echo ""                                                             >&2
249	echo "ERROR: parameter DTx required"                                >&2
250	echo ""                                                             >&2
251	exit 2
252fi
253
254
255# -----  prefer dtc from linux kernel, allow fallback to dtc in $PATH
256
257if [ "${KBUILD_OUTPUT:0:2}" = ".." ] ; then
258	__KBUILD_OUTPUT="${srctree}/${KBUILD_OUTPUT}"
259elif [ "${KBUILD_OUTPUT}" = "" ] ; then
260	__KBUILD_OUTPUT="."
261else
262	__KBUILD_OUTPUT="${KBUILD_OUTPUT}"
263fi
264
265DTC="${__KBUILD_OUTPUT}/scripts/dtc/dtc"
266
267if [ ! -x ${DTC} ] ; then
268	__DTC="dtc"
269	if grep -q "^CONFIG_DTC=y" ${__KBUILD_OUTPUT}/.config 2>/dev/null; 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
282ERROR: 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 '${__DTC}' was also not in \${PATH} or is not executable.
303
304eod
305		exit 2
306	fi
307	DTC=${__DTC}
308fi
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
314dtx_path_1_dtc_include="-i `dirname ${dtx_file_1}`"
315
316dtx_path_2_dtc_include=""
317if (( ${cmd_diff} )) ; then
318	dtx_path_2_dtc_include="-i `dirname ${dtx_file_2}`"
319fi
320
321cpp_flags="\
322	-nostdinc                                  \
323	-I${srctree}/arch/${ARCH}/boot/dts         \
324	-I${srctree}/scripts/dtc/include-prefixes  \
325	-I${srctree}/drivers/of/testcase-data      \
326	-undef -D__DTS__"
327
328dtc_flags="\
329	-i ${srctree}/arch/${ARCH}/boot/dts/ \
330	-i ${srctree}/kernel/dts             \
331	${dtx_path_1_dtc_include}            \
332	${dtx_path_2_dtc_include}"
333
334DTC="${DTC} ${dtc_flags} -O dts -qq -f ${dtc_sort} -o -"
335
336
337# -----  do the diff or decompile
338
339if (( ${cmd_diff} )) ; then
340
341	diff ${diff_flags} --label "${dtx_file_1}" --label "${dtx_file_2}" \
342		<(compile_to_dts "${dtx_file_1}") \
343		<(compile_to_dts "${dtx_file_2}")
344
345else
346
347	compile_to_dts "${dtx_file_1}"
348
349fi
350