On Thu, Dec 31, 2015 at 3:12 AM, Frank Rowand <frowand.list@xxxxxxxxx> wrote: > From: Frank Rowand <frank.rowand@xxxxxxxxxxxxxx> > > Create script to diff device trees. > > The device tree can be in any of the forms recognized by the dtc compiler: > - source > - binary blob > - file system tree (from /proc/devicetree) > > If the device tree is a source file, then it is pre-processed in the > same way as it would be when built in the linux kernel source tree > before diffing. In general, I'd like to see some of this move to dtc and the kernel dependencies minimized. > > Signed-off-by: Frank Rowand <frank.rowand@xxxxxxxxxxxxxx> > --- > > Tools to develop and debug device tree are somewhat inadequate. This is a > small step in improving the situation. > > Rationale for and examples of using the script are provided in slides > 1 - 78 of the elce 2015 presentation "Solving Device Tree Issues", > which can be found at: > > http://elinux.org/images/0/04/Dt_debugging_elce_2015_151006_0421.pdf > > (The script was named dtdiff instead of dtx_diff in the presentation.) > > > scripts/dtc/dtx_diff | 368 +++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 368 insertions(+) > > Index: b/scripts/dtc/dtx_diff > =================================================================== > --- /dev/null > +++ b/scripts/dtc/dtx_diff > @@ -0,0 +1,368 @@ > +#! /bin/bash Add "-e" by default? > + > +# Copyright (C) 2015 Frank Rowand > +# > +# This program is free software; you can redistribute it and/or modify > +# it under the terms of the GNU General Public License as published by > +# the Free Software Foundation; version 2 of the License. > + > + > +usage() { > + > + # use spaces instead of tabs in the usage message > + cat >&2 <<eod > + > +Usage: > + > + `basename $0` DTx > + decompile DTx > + > + `basename $0` DTx_1 DTx_2 > + diff DTx_1 and DTx_2 > + > + > + -f print full dts in diff (--unified=99999) > + -h synonym for --help > + -help synonym for --help > + --help print this message and exit > + -s SRCTREE linux kernel source tree is at path SRCTREE > + (default is current directory) > + -S linux kernel source tree is at root of current git repo Can't this be detected? There are some cases of kernel trees which are not in git. > + -u unsorted, do not sort DTx > + > + > +Each DTx is processed by the dtc compiler to produce a sorted dts source > +file. If DTx is a dts source file then it is pre-processed in the same > +manner as done for the compile of the dts source file in the Linux kernel > +build system ('#include' and '/include/' directives are processed). > + > +If two DTx are provided, the resulting dts source files are diffed. > + > +If DTx is a directory, it is treated as a DT subtree, such as > + /proc/device-tree. > + > +If DTx contains the binary blob magic value in the first four bytes, > + it is treated as a binary blob (aka .dtb or FDT). > + > +Otherwise DTx is treated as a dts source file (aka .dts). > + > + If this script is not run from the root of the linux source tree, > + and DTx utilizes '#include' or '/include/' then the path of the > + linux source tree can be provided by '-s SRCTREE' or '-S' so that > + include paths will be set properly. > + > + The shell variable \${ARCH} must provide the architecture containing > + the dts source file for include paths to be set properly for '#include' > + or '/include/' to be processed. > + > + If DTx_1 and DTx_2 are in different architectures, then this script > + may not work since \${ARCH} is part of the include path. Two possible > + workarounds: > + > + `basename $0` \\ > + <(ARCH=arch_of_dtx_1 `basename $0` DTx_1) \\ > + <(ARCH=arch_of_dtx_2 `basename $0` DTx_2) > + > + `basename $0` ARCH=arch_of_dtx_1 DTx_1 >tmp_dtx_1.dts > + `basename $0` ARCH=arch_of_dtx_2 DTx_2 >tmp_dtx_2.dts > + `basename $0` tmp_dtx_1.dts tmp_dtx_2.dts > + rm tmp_dtx_1.dts tmp_dtx_2.dts > + > + If DTx_1 and DTx_2 are in different directories, then this script will > + add the path of DTx_1 and DTx_2 to the include paths. If DTx_2 includes > + a local file that exists in both the path of DTx_1 and DTx_2 then the > + file in the path of DTx_1 will incorrectly be included. Possible > + workaround: > + > + `basename $0` DTx_1 >tmp_dtx_1.dts > + `basename $0` DTx_2 >tmp_dtx_2.dts > + `basename $0` tmp_dtx_1.dts tmp_dtx_2.dts > + rm tmp_dtx_1.dts tmp_dtx_2.dts > + > +eod > +} > + > + > +compile_to_dts() { > + > + dtx="$1" > + > + if [ -d "${dtx}" ] ; then > + > + # ----- input is file tree > + > + if ( ! ${DTC} -I fs ${dtx} ) ; then > + exit 3 > + fi > + > + elif [ -f "${dtx}" ] && [ -r "${dtx}" ] ; then > + > + magic=`hexdump -n 4 -e '/1 "%02x"' ${dtx}` > + if [ "${magic}" = "d00dfeed" ] ; then Perhaps this auto-detection should be part of dtc? > + > + # ----- input is FDT (binary blob) > + > + if ( ! ${DTC} -I dtb ${dtx} ) ; then > + exit 3 > + fi > + > + else > + > + # ----- input is DTS (source) > + > + if ( cpp ${cpp_flags} -x assembler-with-cpp ${dtx} | ${DTC} -I dts ) ; then > + return > + fi > + > + echo "" >&2 > + echo "Possible hints to resolve the above error:" >&2 > + echo " (hints might not fix the problem)" >&2 > + > + hint_given=0 > + > + if [ "${ARCH}" = "" ] ; then > + hint_given=1 > + echo "" >&2 > + echo " shell variable \$ARCH not set" >&2 > + fi > + > + dtx_arch=`echo "/${dtx}" | sed -e 's|.*/arch/||' -e 's|/.*||'` > + > + if [ "${dtx_arch}" != "" -a "${dtx_arch}" != "${ARCH}" ] ; then > + hint_given=1 > + echo "" >&2 > + echo " architecture ${dtx_arch} is in file path, but" >&2 > + echo " does not match shell variable \$ARCH (${ARCH})" >&2 > + fi > + > + if [ ! -d ${srctree}/arch/${ARCH} ] ; then > + hint_given=1 > + echo "" >&2 > + echo " ${srctree}/arch/${ARCH}/ does not exist" >&2 > + echo " Is \$ARCH='${ARCH}' correct?" >&2 > + echo " Possible fix: use '-s' option" >&2 > + > + git_root=`git rev-parse --show-toplevel 2>/dev/null` > + if [ -d ${git_root}/arch/ ] ; then > + echo " Possible fix: use '-S' option" >&2 > + fi > + fi > + > + if [ $hint_given = 0 ] ; then > + echo "" >&2 > + echo " No hints available." >&2 > + fi > + > + echo "" >&2 > + > + exit 3 > + > + fi > + else > + echo "" >&2 > + echo "ERROR: ${dtx} does not exist or is not readable" >&2 > + echo "" >&2 > + exit 2 > + fi > + > +} > + > + > +# ----- start of script > + > +cmd_diff=0 > +diff_flags="-u" > +dtx_file_1="" > +dtx_file_2="" > +dtc_sort="-s" > +help=0 > +srctree="" > + > + > +while [ $# -gt 0 ] ; do > + > + case $1 in > + > + -f ) > + diff_flags="--unified=999999" > + shift > + ;; > + > + -h | -help | --help ) > + help=1 > + shift > + ;; > + > + -s ) > + srctree="$2" > + shift 2 > + ;; > + > + -S ) > + git_root=`git rev-parse --show-toplevel 2>/dev/null` > + srctree="${git_root}" > + shift > + ;; > + > + -u ) > + dtc_sort="" > + shift > + ;; > + > + *) > + if [ "${dtx_file_1}" = "" ] ; then > + dtx_file_1="$1" > + elif [ "${dtx_file_2}" = "" ] ; then > + dtx_file_2="$1" > + else > + echo "" >&2 > + echo "ERROR: Unexpected parameter: $1" >&2 > + echo "" >&2 > + exit 2 > + fi > + shift > + ;; > + > + esac > + > +done > + > +if [ "${srctree}" = "" ] ; then > + srctree="." > +fi > + > +if [ "${dtx_file_2}" != "" ]; then > + cmd_diff=1 > +fi > + > +if (( ${help} )) ; then > + usage > + exit 1 > +fi > + > +# this must follow check for ${help} > +if [ "${dtx_file_1}" = "" ]; then > + echo "" >&2 > + echo "ERROR: parameter DTx required" >&2 > + echo "" >&2 > + exit 2 > +fi > + > + > +# ----- prefer dtc from linux kernel, allow fallback to dtc in $PATH > + > +if [ "${KBUILD_OUTPUT:0:2}" = ".." ] ; then > + __KBUILD_OUTPUT="${srctree}/${KBUILD_OUTPUT}" > +elif [ "${KBUILD_OUTPUT}" = "" ] ; then > + __KBUILD_OUTPUT="." > +else > + __KBUILD_OUTPUT="${KBUILD_OUTPUT}" > +fi > + > +DTC="${__KBUILD_OUTPUT}/scripts/dtc/dtc" > + > +if [ ! -x ${DTC} ] ; then > + __DTC="dtc" > + if ( ! which ${__DTC} >/dev/null ) ; then > + > + # use spaces instead of tabs in the error message > + cat >&2 <<eod > + > +ERROR: unable to find a 'dtc' program > + > + Preferred 'dtc' (built from Linux kernel source tree) was not found or > + is not executable. > + > + 'dtc' is: ${DTC} > + > + If it does not exist, create it from the root of the Linux source tree: > + > + 'make scripts'. > + > + If not at the root of the Linux kernel source tree -s SRCTREE or -S > + may need to be specified to find 'dtc'. > + > + If 'O=\${dir}' is specified in your Linux builds, this script requires > + 'export KBUILD_OUTPUT=\${dir}' or add \${dir}/scripts/dtc to \$PATH > + before running. > + > + If \${KBUILD_OUTPUT} is a relative path, then '-s SRCDIR', -S, or run > + this script from the root of the Linux kernel source tree is required. > + > + Fallback '${__DTC}' was also not in \${PATH} or is not executable. > + > +eod > + exit 2 > + fi > + DTC=${__DTC} > +fi > + > + > +# ----- cpp and dtc flags same as for linux source tree build of .dtb files, > +# plus directories of the dtx file(s) > + > +dtx_path_1_dtc_include="-i `dirname ${dtx_file_1}`" > + > +dtx_path_2_dtc_include="" > +if (( ${cmd_diff} )) ; then > + dtx_path_2_dtc_include="-i `dirname ${dtx_file_2}`" > +fi > + > +cpp_flags="\ > + -nostdinc \ > + -I${srctree}/arch/${ARCH}/boot/dts \ > + -I${srctree}/arch/${ARCH}/boot/dts/include \ > + -I${srctree}/arch/${ARCH}/boot/dts/include/dt-bindings \ kernel doesn't use this path. The less dependency on ARCH, the better. The dependency in the kernel is artificial. > + -I${srctree}/drivers/of/testcase-data \ > + -undef -D__DTS__" > + > +_dts_makefile="" > + > +if [ -f ${srctree}/arch/${ARCH}/boot/dts/Makefile ] ; then > + _dts_makefile="${srctree}/arch/${ARCH}/boot/dts/Makefile" > +elif [ -f ${srctree}/arch/${ARCH}/boot/Makefile ] ; then > + # arch/powerpc > + _dts_makefile="${srctree}/arch/${ARCH}/boot/Makefile" We need to move PPC to be in line with other arches rather than working around it. > +fi > + > +if [ "${_dts_makefile}" != "" ] ; then > + arch_dtc_flags=`grep DTC_FLAGS ${_dts_makefile} \ We should just kill DTC_FLAGS being per arch. Plus it is only used for padding, so it is irrelevant to this tool. > + | grep -v "^#" \ > + | sed -e 's|.*=||' ` > +else > + arch_dtc_flags="" > +fi > + > +dtc_flags="\ > + -i ${srctree}/arch/${ARCH}/boot/dts/ \ > + -i ${srctree}/kernel/dts \ > + ${dtx_path_1_dtc_include} \ > + ${dtx_path_2_dtc_include} \ > + ${arch_dtc_flags}" > + > +DTC="${DTC} ${dtc_flags} -O dts -qq -f ${dtc_sort} -o -" > + > + > +# ----- do the diff or decompile > + > +if (( ${cmd_diff} )) ; then > + > + diff ${diff_flags} \ > + <(compile_to_dts "${dtx_file_1}") \ > + <(compile_to_dts "${dtx_file_2}") > + > +else > + > + compile_to_dts "${dtx_file_1}" > + > +fi > + > + > +# ============================================================================== > +# ______________________________________________________________________________ > +# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - > +# ______________________________________________________________________________ > +# vi config follows: > +# > +# add "set modelines" to ~/.exrc or ~/.vimrc to set tabs automatically > +# ex:set tabstop=4 shiftwidth=4 sts=4: Kernel standard is 8 characters. I assume that applies to bash files too. Rob -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
