xref: /openbmc/linux/scripts/dtc/dtx_diff (revision 8e74a48d) 
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
33                        (-T -T for more details)
34       -u           unsorted, do not sort DTx
35
36
37Each DTx is processed by the dtc compiler to produce a sorted dts source
38file.  If DTx is a dts source file then it is pre-processed in the same
39manner as done for the compile of the dts source file in the Linux kernel
40build system ('#include' and '/include/' directives are processed).
41
42If two DTx are provided, the resulting dts source files are diffed.
43
44If DTx is a directory, it is treated as a DT subtree, such as
45  /proc/device-tree.
46
47If DTx contains the binary blob magic value in the first four bytes,
48  it is treated as a binary blob (aka .dtb or FDT).
49
50Otherwise DTx is treated as a dts source file (aka .dts).
51
52   If this script is not run from the root of the linux source tree,
53   and DTx utilizes '#include' or '/include/' then the path of the
54   linux source tree can be provided by '-s SRCTREE' or '-S' so that
55   include paths will be set properly.
56
57   The shell variable \${ARCH} must provide the architecture containing
58   the dts source file for include paths to be set properly for '#include'
59   or '/include/' to be processed.
60
61   If DTx_1 and DTx_2 are in different architectures, then this script
62   may not work since \${ARCH} is part of the include path.  The following
63   workaround can be used:
64
65      `basename $0` ARCH=arch_of_dtx_1 DTx_1 >tmp_dtx_1.dts
66      `basename $0` ARCH=arch_of_dtx_2 DTx_2 >tmp_dtx_2.dts
67      `basename $0` tmp_dtx_1.dts tmp_dtx_2.dts
68      rm tmp_dtx_1.dts tmp_dtx_2.dts
69
70   If DTx_1 and DTx_2 are in different directories, then this script will
71   add the path of DTx_1 and DTx_2 to the include paths.  If DTx_2 includes
72   a local file that exists in both the path of DTx_1 and DTx_2 then the
73   file in the path of DTx_1 will incorrectly be included.  Possible
74   workaround:
75
76      `basename $0` DTx_1 >tmp_dtx_1.dts
77      `basename $0` DTx_2 >tmp_dtx_2.dts
78      `basename $0` tmp_dtx_1.dts tmp_dtx_2.dts
79      rm tmp_dtx_1.dts tmp_dtx_2.dts
80
81eod
82}
83
84
85compile_to_dts() {
86
87	dtx="$1"
88	dtc_include="$2"
89
90	if [ -d "${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} ${dtc_include} -I dts ) ; then
117			return
118		fi
119
120		echo ""                                                      >&2
121		echo "Possible hints to resolve the above error:"            >&2
122		echo "  (hints might not fix the problem)"                   >&2
123
124		hint_given=0
125
126		if [ "${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
176annotate=""
177cmd_diff=0
178diff_flags="-u"
179diff_color=""
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	-c | --color )
192		if diff --color /dev/null /dev/null 2>/dev/null ; then
193			diff_color="--color=always"
194		fi
195		shift
196		;;
197
198	-f )
199		diff_flags="--unified=999999"
200		shift
201		;;
202
203	-h | -help | --help )
204		help=1
205		shift
206		;;
207
208	-s )
209		srctree="$2"
210		shift 2
211		;;
212
213	-S )
214		git_root=`git rev-parse --show-toplevel 2>/dev/null`
215		srctree="${git_root}"
216		shift
217		;;
218
219	-T | --annotate )
220		if [ "${annotate}"  = "" ] ; then
221			annotate="-T"
222		elif [ "${annotate}"  = "-T" ] ; then
223			annotate="-T -T"
224		fi
225		shift
226		;;
227	-u )
228		dtc_sort=""
229		shift
230		;;
231
232	*)
233		if [ "${dtx_file_1}"  = "" ] ; then
234			dtx_file_1="$1"
235		elif [ "${dtx_file_2}" = "" ] ; then
236			dtx_file_2="$1"
237		else
238			echo ""                                             >&2
239			echo "ERROR: Unexpected parameter: $1"              >&2
240			echo ""                                             >&2
241			exit 2
242		fi
243		shift
244		;;
245
246	esac
247
248done
249
250if [ "${srctree}" = "" ] ; then
251	srctree="."
252fi
253
254if [ "${dtx_file_2}" != "" ]; then
255	cmd_diff=1
256fi
257
258if (( ${help} )) ; then
259	usage
260	exit 1
261fi
262
263# this must follow check for ${help}
264if [ "${dtx_file_1}" = "" ]; then
265	echo ""                                                             >&2
266	echo "ERROR: parameter DTx required"                                >&2
267	echo ""                                                             >&2
268	exit 2
269fi
270
271
272# -----  prefer dtc from linux kernel, allow fallback to dtc in $PATH
273
274if [ "${KBUILD_OUTPUT:0:2}" = ".." ] ; then
275	__KBUILD_OUTPUT="${srctree}/${KBUILD_OUTPUT}"
276elif [ "${KBUILD_OUTPUT}" = "" ] ; then
277	__KBUILD_OUTPUT="."
278else
279	__KBUILD_OUTPUT="${KBUILD_OUTPUT}"
280fi
281
282DTC="${__KBUILD_OUTPUT}/scripts/dtc/dtc"
283
284if [ ! -x ${DTC} ] ; then
285	__DTC="dtc"
286	if grep -q "^CONFIG_DTC=y" ${__KBUILD_OUTPUT}/.config 2>/dev/null; then
287		make_command='
288         make scripts'
289	else
290		make_command='
291         Enable CONFIG_DTC in the kernel configuration
292         make scripts'
293	fi
294	if ( ! which ${__DTC} >/dev/null ) ; then
295
296		# use spaces instead of tabs in the error message
297		cat >&2 <<eod
298
299ERROR: unable to find a 'dtc' program
300
301   Preferred 'dtc' (built from Linux kernel source tree) was not found or
302   is not executable.
303
304      'dtc' is: ${DTC}
305
306      If it does not exist, create it from the root of the Linux source tree:
307${make_command}
308
309      If not at the root of the Linux kernel source tree -s SRCTREE or -S
310      may need to be specified to find 'dtc'.
311
312      If 'O=\${dir}' is specified in your Linux builds, this script requires
313      'export KBUILD_OUTPUT=\${dir}' or add \${dir}/scripts/dtc to \$PATH
314      before running.
315
316      If \${KBUILD_OUTPUT} is a relative path, then '-s SRCDIR', -S, or run
317      this script from the root of the Linux kernel source tree is required.
318
319   Fallback '${__DTC}' was also not in \${PATH} or is not executable.
320
321eod
322		exit 2
323	fi
324	DTC=${__DTC}
325fi
326
327
328# -----  cpp and dtc flags same as for linux source tree build of .dtb files,
329#        plus directories of the dtx file(s)
330
331dtx_path_1_dtc_include="-i `dirname ${dtx_file_1}`"
332
333dtx_path_2_dtc_include=""
334if (( ${cmd_diff} )) ; then
335	dtx_path_2_dtc_include="-i `dirname ${dtx_file_2}`"
336fi
337
338cpp_flags="\
339	-nostdinc                                  \
340	-I${srctree}/scripts/dtc/include-prefixes  \
341	-undef -D__DTS__"
342
343DTC="\
344	${DTC}                                     \
345	-i ${srctree}/scripts/dtc/include-prefixes \
346	-O dts -qq -f ${dtc_sort} ${annotate} -o -"
347
348
349# -----  do the diff or decompile
350
351if (( ${cmd_diff} )) ; then
352
353	diff ${diff_flags} ${diff_color} --label "${dtx_file_1}" --label "${dtx_file_2}" \
354		<(compile_to_dts "${dtx_file_1}" "${dtx_path_1_dtc_include}") \
355		<(compile_to_dts "${dtx_file_2}" "${dtx_path_2_dtc_include}")
356
357else
358
359	compile_to_dts "${dtx_file_1}" "${dtx_path_1_dtc_include}"
360
361fi
362