xref: /openbmc/linux/scripts/dtc/dtx_diff (revision ba61bb17) 
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	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
177cmd_diff=0
178diff_flags="-u"
179dtx_file_1=""
180dtx_file_2=""
181dtc_sort="-s"
182help=0
183srctree=""
184
185
186while [ $# -gt 0 ] ; do
187
188	case $1 in
189
190	-f )
191		diff_flags="--unified=999999"
192		shift
193		;;
194
195	-h | -help | --help )
196		help=1
197		shift
198		;;
199
200	-s )
201		srctree="$2"
202		shift 2
203		;;
204
205	-S )
206		git_root=`git rev-parse --show-toplevel 2>/dev/null`
207		srctree="${git_root}"
208		shift
209		;;
210
211	-u )
212		dtc_sort=""
213		shift
214		;;
215
216	*)
217		if [ "${dtx_file_1}"  = "" ] ; then
218			dtx_file_1="$1"
219		elif [ "${dtx_file_2}" = "" ] ; then
220			dtx_file_2="$1"
221		else
222			echo ""                                             >&2
223			echo "ERROR: Unexpected parameter: $1"              >&2
224			echo ""                                             >&2
225			exit 2
226		fi
227		shift
228		;;
229
230	esac
231
232done
233
234if [ "${srctree}" = "" ] ; then
235	srctree="."
236fi
237
238if [ "${dtx_file_2}" != "" ]; then
239	cmd_diff=1
240fi
241
242if (( ${help} )) ; then
243	usage
244	exit 1
245fi
246
247# this must follow check for ${help}
248if [ "${dtx_file_1}" = "" ]; then
249	echo ""                                                             >&2
250	echo "ERROR: parameter DTx required"                                >&2
251	echo ""                                                             >&2
252	exit 2
253fi
254
255
256# -----  prefer dtc from linux kernel, allow fallback to dtc in $PATH
257
258if [ "${KBUILD_OUTPUT:0:2}" = ".." ] ; then
259	__KBUILD_OUTPUT="${srctree}/${KBUILD_OUTPUT}"
260elif [ "${KBUILD_OUTPUT}" = "" ] ; then
261	__KBUILD_OUTPUT="."
262else
263	__KBUILD_OUTPUT="${KBUILD_OUTPUT}"
264fi
265
266DTC="${__KBUILD_OUTPUT}/scripts/dtc/dtc"
267
268if [ ! -x ${DTC} ] ; then
269	__DTC="dtc"
270	if grep -q "^CONFIG_DTC=y" ${__KBUILD_OUTPUT}/.config 2>/dev/null; then
271		make_command='
272         make scripts'
273	else
274		make_command='
275         Enable CONFIG_DTC in the kernel configuration
276         make scripts'
277	fi
278	if ( ! which ${__DTC} >/dev/null ) ; then
279
280		# use spaces instead of tabs in the error message
281		cat >&2 <<eod
282
283ERROR: unable to find a 'dtc' program
284
285   Preferred 'dtc' (built from Linux kernel source tree) was not found or
286   is not executable.
287
288      'dtc' is: ${DTC}
289
290      If it does not exist, create it from the root of the Linux source tree:
291${make_command}
292
293      If not at the root of the Linux kernel source tree -s SRCTREE or -S
294      may need to be specified to find 'dtc'.
295
296      If 'O=\${dir}' is specified in your Linux builds, this script requires
297      'export KBUILD_OUTPUT=\${dir}' or add \${dir}/scripts/dtc to \$PATH
298      before running.
299
300      If \${KBUILD_OUTPUT} is a relative path, then '-s SRCDIR', -S, or run
301      this script from the root of the Linux kernel source tree is required.
302
303   Fallback '${__DTC}' was also not in \${PATH} or is not executable.
304
305eod
306		exit 2
307	fi
308	DTC=${__DTC}
309fi
310
311
312# -----  cpp and dtc flags same as for linux source tree build of .dtb files,
313#        plus directories of the dtx file(s)
314
315dtx_path_1_dtc_include="-i `dirname ${dtx_file_1}`"
316
317dtx_path_2_dtc_include=""
318if (( ${cmd_diff} )) ; then
319	dtx_path_2_dtc_include="-i `dirname ${dtx_file_2}`"
320fi
321
322cpp_flags="\
323	-nostdinc                                  \
324	-I${srctree}/scripts/dtc/include-prefixes  \
325	-undef -D__DTS__"
326
327DTC="\
328	${DTC}                                     \
329	-i ${srctree}/scripts/dtc/include-prefixes \
330	-O dts -qq -f ${dtc_sort} -o -"
331
332
333# -----  do the diff or decompile
334
335if (( ${cmd_diff} )) ; then
336
337	diff ${diff_flags} --label "${dtx_file_1}" --label "${dtx_file_2}" \
338		<(compile_to_dts "${dtx_file_1}" "${dtx_path_1_dtc_include}") \
339		<(compile_to_dts "${dtx_file_2}" "${dtx_path_2_dtc_include}")
340
341else
342
343	compile_to_dts "${dtx_file_1}" "${dtx_path_1_dtc_include}"
344
345fi
346