diff options
| -rw-r--r-- | resources/scripts/misc/grubeditor.sh | 396 |
1 files changed, 396 insertions, 0 deletions
diff --git a/resources/scripts/misc/grubeditor.sh b/resources/scripts/misc/grubeditor.sh new file mode 100644 index 00000000..025161f3 --- /dev/null +++ b/resources/scripts/misc/grubeditor.sh @@ -0,0 +1,396 @@ +#!/bin/bash +# +# grubeditor.sh -- conveniently edit grub{test}.cfg files by automating their +# extraction with cbfstool and the user's editor of choice. +# +# Copyright (C) 2017 Zyliwax <zyliwax@protonmail.com> +# +# 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, either version 3 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see <http://www.gnu.org/licenses/>. +# + +# Usage: +# ./grubeditor.sh [options] romimage +# +# Supported options: +# +# -h | --help: show usage help +# +# -r | --realcfg: generate grub.cfg instead of grubtest.cfg +# +# -i | --inplace: do not create a .modified romfile, instead modify the +# existing file +# +# -e | --editor /path/to/editor: open the cfg file with /path/to/editor instead +# of $EDITOR +# +# -s | --swapcfg: swap grub.cfg and grubtest.cfg, incompatible with other +# options besides -i +# +# -x | --extractcfg: extract either grub.cfg or grubtest.cfg depending on +# whether -r is set +# +# -d | --diffcfg: diff grub.cfg and grubtest.cfg, incompatible with other +# options besides -D +# +# -D | --differ [/path/to/]differ: use /path/to/differ instead of "diff", can +# be an interactive program like vimdiff + +# Define the list of available option in both short and long form. +shortopts="hrie:sdD:" +longopts="help,realcfg,inplace,editor:,swapcfgs,diffcfgs,differ:" + +# Variables for modifying the program's operation +edit_realcfg=0 +edit_inplace=0 +do_swapcfgs=0 +do_diffcfgs=0 +# Path to cbfstool, filled by detect_architecture +# (Possible to provide explicitly and disclaim warranty?) +cbfstool="" +# Editor variables +use_editor="" +default_editor="vi" +editor_rawarg="" +# Differ variables +use_differ="" +default_differ="diff" +differ_rawarg="" +# Last but not least, the rom file itself +romfile="" + +# This program works primarily from a cascade of functions. Let's define them. + +get_options() { + # Test for enhanced getopt. + getopt --test > /dev/null + if [[ $? -ne 4 ]]; then + echo "Your environment lacks enhanced getopt, so you cannot run this script properly." + exit 205 + fi + + # Parse the command line options based on the previously defined values. + parsedopts=$(getopt --options ${shortopts} --longoptions ${longopts} --name "${0}" -- "$@") + if [[ $? -ne 0 ]]; then # getopt didn't approve of your arguments + echo "Unrecognized options." + exit 206 + fi + + # Use eval set to properly quote the arguments + eval set -- "$parsedopts" + + # Interpret the arguments one-by-one until you run out. + while [[ 1 ]]; do + case "$1" in + -h|--help) + show_help + # I return non-zero here just so nobody thinks we successfully edited grub.cfg + exit 200 + ;; + -r|--realcfg) + edit_realcfg=1 + shift + ;; + -i|--inplace) + edit_inplace=1 + shift + ;; + -e|--editor) + editor_rawarg="$2" + shift 2 + ;; + -s|--swapcfgs) + do_swapcfgs=1 + shift + ;; + -d|--diffcfgs) + do_diffcfgs=1 + shift + ;; + -D|--differ) + differ_rawarg="$2" + shift 2 + ;; + --) + # Stop interpreting arguments magically. + shift + break + ;; + *) + echo "Something went wrong while interpreting the arguments!" + echo "I hit \"${1}\" and don't know what to do with it." + exit 209 + ;; + esac + done + + # The only option remaining should be the input file. Ensure it was + # provided before proceeding with the rest of the script and capture it if + # it was. + if [[ $# -ne 1 ]]; then + echo "You have specified multiple (or no) input files, which is unsupported." + echo "Please rerun this command with just a single filename to remove any chance for ambiguity." + exit 210 + fi + romfile="$1" +} + +determine_architecture() { + # The cbfstool in _util is packed only for i686, x86_64, and armv7l. This + # procedure is necessary for this process to not fail. After this process + # is over, the variable $cbfstool gets filled with the appropriate value + # for use by the rest of the script. + arch="$(uname -m)" + case "${arch}" in + armv7l|i686|x86_64) + echo "Supported architecture \"${arch}\" detected. You may proceed." + cbfstool="./cbfstool/${arch}/cbfstool" + ;; + *) + echo "Unsupported architecture \"${arch}\" detected! You may not proceed." + exit 230 + ;; + esac +} + +determine_operation() { + if [[ $do_swapcfgs -eq 1 ]]; then + swap_configs + exit $? + elif [[ $do_diffcfgs -eq 1 ]]; then + diff_configs + exit $? + else + edit_config + exit $? + fi +} + +# These functions are not part of the primary function cascade but are +# referenced within them either directly or indirectly from other helper +# functions depending on the operations requested by the user. + +show_help() { + cat << HELPSCREEN +${0} -- conveniently edit grub{test}.cfg files in Libreboot ROM image files by +automating their extraction with cbfstool and the user's editor of choice. + +-h | --help: show usage help + +-r | --realcfg: generate grub.cfg instead of grubtest.cfg + +-i | --inplace: do not create a .modified romfile, instead modify the +existing file + +-e | --editor [/path/to/]editor: open the cfg file with /path/to/editor instead +of the value of \$EDITOR + +-s | --swapcfg: swap grub.cfg and grubtest.cfg + +-d | --diffcfg: diff grub.cfg and grubtest.cfg + +-D | --differ [/path/to/]differ: use /path/to/differ instead of "diff", can be +an interactive program like vimdiff +HELPSCREEN +} + +swap_configs() { + # Procedure: + # 1. Call cbfstool twice, once each to extract grub.cfg and grubtest.cfg. + # 2. If --inplace not specified, copy ${romfile} to ${romfile}.modified and + # implement remaining steps on this copy. Otherwise, implement remaining + # steps on ${romfile}. + # 3. Call cbfstool twice, once each to delete grub.cfg and grubtest.cfg + # from romfile. + # 4. Call cbfstool twice, once to embed grubtest.cfg as grub.cfg into + # romfile and again to embed grub.cfg as grubtest.cfg into romfile. + # 5. Delete the extracted grub.cfg and grubtest.cfg files. + # 6. You're done! + + # Extract config files from provided romfile. + ${cbfstool} ${romfile} extract -n grub.cfg -f /tmp/real2test.cfg + ${cbfstool} ${romfile} extract -n grubtest.cfg -f /tmp/test2real.cfg + + # Determine whether to edit inplace or make a copy. + if [[ $edit_inplace -eq 1 ]]; then + outfile="${romfile}" + else + cp "${romfile}" "${romfile}.modified" + outfile="${romfile}.modified" + fi + + # Remove config files from the output file. + ${cbfstool} ${outfile} remove -n grub.cfg + ${cbfstool} ${outfile} remove -n grubtest.cfg + + # Embed new configs into the output file. + ${cbfstool} ${outfile} add -t raw -n grub.cfg -f /tmp/test2real.cfg + ${cbfstool} ${outfile} add -t raw -n grubtest.cfg -f /tmp/real2test.cfg + + # Delete the tempfiles. + rm /tmp/test2real.cfg /tmp/real2test.cfg +} + +diff_configs() { + # Procedure: + # 1. Call cbfstool twice, once to extract grub.cfg and grubtest.cfg. + # 2. Execute ${use_differ} grub.cfg grubtest.cfg #. + # 3. Delete the extracted grub.cfg and grubtest.cfg files. + # 4. You're done! + + # Determine the differ command to use. + find_differ + + # Extract config files from provided romfile. + ${cbfstool} ${romfile} extract -n grub.cfg -f /tmp/grub_tmpdiff.cfg + ${cbfstool} ${romfile} extract -n grubtest.cfg -f /tmp/grubtest_tmpdiff.cfg + + # Run the differ command with real as first option, test as second option. + ${use_differ} /tmp/grub_tmpdiff.cfg /tmp/grubtest_tmpdiff.cfg +} + +edit_config() { + # Procedure: + # 1. If --realcfg specified, set ${thisconfig} to "grub.cfg". Otherwise, + # set ${thisconfig} to "grubtest.cfg". + # 2. Call cbfstool once to extract ${thisconfig} from ${romfile}. + # 3. Run ${use_editor} ${thisconfig}. + # 4. If ${use_editor} returns zero, proceed with update procedure: + # 5. Call cbfstool once to extract ${thisconfig} from ${romfile}. + # 6. Quietly diff the extracted file with the edited file. If diff returns + # zero, take no action: warn the user that the files were the same, delete + # both files, then skip the remaining steps (you're done)! Otherwise, the + # files are different and you must continue with the update procedure. + # 7. If --inplace not specified, copy ${romfile} to ${romfile}.modified and + # implement remaining steps on this copy. Otherwise, implement remaining + # steps on ${romfile}. + # 8. Call cbfstool once to delete internal pre-update ${thisconfig} from + # the rom file. + # 9. Call cbfstool once to embed the updated ${thisconfig} that was just + # edited into the rom file. + # 10. Alert the user of success (either explicitly or by not saying + # anything, either way return zero). + # 11. You're done! + + # Determine the editor command to use. + find_editor + + # Determine whether we are editing the real config or the test config. + if [[ $edit_realcfg -eq 1 ]]; then + thisconfig="grub.cfg" + else + thisconfig="grubtest.cfg" + fi + + # Extract the desired configuration file from the romfile. + tmp_editme="/tmp/${thisconfig%.cfg}_editme.cfg" + ${cbfstool} ${romfile} extract -n ${thisconfig} -f ${tmp_editme} + + # Launch the editor! + ${use_editor} ${tmp_editme} + + # Did the user commit the edit? + if [[ $? -eq 0 ]]; then + # See if it actually changed from what exists in the cbfs. + tmp_refcfg="/tmp/${thisconfig%.cfg}_ref.cfg" + ${cbfstool} ${romfile} extract -n ${thisconfig} -f ${tmp_refcfg} + # Diff the files as quietly as possible. + diff -q ${tmp_editme} ${tmp_refcfg} &> /dev/null + if [[ $? -ne 0 ]]; then + # The files differ, so it won't be frivolous to update the config. + # See if the user wants to edit the file in place. + # (This code should really be genericized and placed in a function + # to avoid repetition.) + if [[ $edit_inplace -eq 1 ]]; then + outfile="${romfile}" + else + cp "${romfile}" "${romfile}.modified" + outfile="${romfile}.modified" + fi + # Remove the old config, add in the new one. + ${cbfstool} ${outfile} remove -n ${thisconfig} + ${cbfstool} ${outfile} add -t raw -n ${thisconfig} -f ${tmp_editme} + else + echo "No changes to config file. Not updating the ROM image." + fi + # We are done with the config files. Delete them. + rm ${tmp_editme} + rm ${tmp_refcfg} + fi +} + +find_differ() { + found_differ=0 + + if [[ -n "${differ_rawarg}" ]]; then + which "${differ_rawarg}" &> /dev/null + if [[ $? -eq 0 ]]; then + echo "Using differ \"${differ_rawarg}\"..." + use_differ="${differ_rawarg}" + found_differ=1 + else + echo "The provided \"${differ_rawarg}\" is not a valid command!" + echo "Defaulting to ${default_differ}..." + use_differ="${default_differ}" + fi + fi + + if [[ $found_differ -eq 1 ]]; then + return + else + echo "Defaulting to ${default_differ}..." + use_differ="${default_differ}" + fi +} + +find_editor() { + found_editor=0 + + if [[ -n "${editor_rawarg}" ]]; then + which "${editor_rawarg}" &> /dev/null + if [[ $? -eq 0 ]]; then + echo "Using editor \"${editor_rawarg}\"..." + use_editor="${editor_rawarg}" + found_editor=1 + else + echo "The provided \"${editor_rawarg}\" is not a valid command!" + echo "Defaulting to ${default_editor}..." + use_editor="${default_editor}" + fi + fi + + if [[ $found_editor -eq 1 ]]; then + return + else + if [[ -n "${EDITOR}" ]]; then + which "${EDITOR}" &> /dev/null + if [[ $? -ne 0 ]]; then + echo "Your \$EDITOR is defined as ${EDITOR}, but is not a valid command!" + echo "(This is bad. I highly suggest fixing this in your ~/.bashrc.)" + echo "Defaulting to ${default_editor}..." + use_editor="${default_editor}" + else + echo "Using your defined \$EDITOR \"$EDITOR\"..." + use_editor="${EDITOR}" + fi + else + echo "\$EDITOR blank, defaulting to ${default_editor}..." + use_editor="${default_editor}" + fi + fi +} + +# Run through the primary function cascade. +get_options $@ +determine_architecture +determine_operation |