AMiRo-OS

################################################################################

# AMiRo-OS is an operating system designed for the Autonomous Mini Robot       #

# (AMiRo) platform.                                                            #

# Copyright (C) 2016..2019  Thomas Schöpping et al.                            #

#                                                                              #

# 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/>.        #

#                                                                              #

# This research/work was supported by the Cluster of Excellence Cognitive      #

# Interaction Technology 'CITEC' (EXC 277) at Bielefeld University, which is   #

# funded by the German Research Foundation (DFG).                              #

################################################################################

#!/bin/bash

################################################################################

# GENERIC FUNCTIONS                                                            #

################################################################################

### print an error message #####################################################

# Prints a error <message> to standard output.

#If variable 'LOG_FILE' is specified, the message is also appended to the given file.

#

# usage:      printError <message>

# arguments:  <message>

#                 Message string to print.

# return:     n/a

#

function printError {

  local string="ERROR:   $1"

  # if a log file is specified

  if [ -n "$LOG_FILE" ]; then

    printf "[$(date '+%Y-%m-%d %H:%M:%S')] $string" >> $LOG_FILE

  fi

  printf "$(tput setaf 1)>>> $string$(tput sgr 0)" 1>&2

}

### print a warning message ####################################################

# Prints a warning <message> to standard output.

#If variable 'LOG_FILE' is specified, the message is also appended to the given file.

#

# usage:      printMessage <message>

# arguments:  <message>

#                 Message string to print.

# return:     n/a

#

function printWarning {

  local string="WARNING: $1"

  # if a log file is specified

  if [ -n "$LOG_FILE" ]; then

    printf "[$(date '+%Y-%m-%d %H:%M:%S')] $string" >> $LOG_FILE

  fi

  printf "$(tput setaf 3)>>> $string$(tput sgr 0)"

}

### print an information message ###############################################

# Prints an information <message> to standard output.

#If variable 'LOG_FILE' is specified, the message is also appended to the given file.

#

# usage:      printInfo <message>

# arguments:  <message>

#                 Message string to print.

# return:     n/a

#

function printInfo {

  local string="INFO:    $1"

  # if a log file is specified

  if [ -n "$LOG_FILE" ]; then

    printf "[$(date '+%Y-%m-%d %H:%M:%S')] $string" >> $LOG_FILE

  fi

  printf "$(tput setaf 2)>>> $string$(tput sgr 0)"

}

### print a message to file ####################################################

# Appends a <message> to a log file, specified by the variable 'LOG_FILE'.

#

# usage       printLog <message>

# arguments:  <message>

#                 Message string to print.

# return:     n/a

#

function printLog {

  local string="LOG:     $1"

  # if a log file is specified

  if [ -n "$LOG_FILE" ]; then

    printf "[$(date '+%Y-%m-%d %H:%M:%S')] $string" >> $LOG_FILE

  fi

}

### exit the script normally ###################################################

# Prints a delimiter and exits the script normally (returns 0).

#

# usage:      quitScript

# arguments:  n/a

# return:     0

#                 No error or warning occurred.

#

function quitScript {

  printInfo "exiting $(realpath ${BASH_SOURCE[0]})\n"

  printf "\n"

  printf "######################################################################\n"

  exit 0

}

### read a user input ##########################################################

# Reads a single character user input from a set up <options> and stores it in

# a given <return> variable.

#

# usage:      readUserInput <options> <return>

# arguments:  <options>

#                 String definiing the set of valid characters.

#                 If the string is empty, the user can input any character.

#             <return>

#                 Variable to store the selected character to.

# return:     n/a

#

function readUserInput {

  local input=""

  # read user input

  while [ -z $input ] || ( [ -n "$1" ] && [[ ! $input =~ ^[$1]$ ]] ); do

    read -p "your selection: " -n 1 -e input

    if [ -z $input ] || ( [ -n "$1" ] && [[ ! $input =~ ^[$1]$ ]] ); then

      printWarning "[$input] is no valid action\n"

    fi

  done

  printLog "[$input] has been selected\n"

  eval $2="$input"

}

### check whether argument is an option ########################################

# Checks a <string> whether it is an option.

# Options are defined to either start with '--' followed by any string, or

# to start with a single '-' followed by a single character, or

# to start with a single '-' followed by a single character, a '=' and any string.

# Examples: '--option', '--option=arg', '-o', '-o=arg', '--'

#

# usage:      parseIsOption <string>

# arguments:  <string>

#                 A string to check whether it is an option.

# return:     0

#                 <string> is an option.

#             -1

#                 <string> is not an option.

#

function parseIsOption {

  if [[ "$1" =~ ^-(.$|.=.*) ]] || [[ "$1" =~ ^--.* ]]; then

    return 0

  else

    return -1

  fi

}

### set the log file ###########################################################

# Sets a specified <infile> as log file and checks whether it already exists.

# If so, the log may either be appended to the file, its content can be cleared,

# or no log is generated at all.

# The resulting path is stored in <outvar>.

#

# usage:      setLogFile [--option=<option>] [--quiet] <infile> <outvar>

# arguments:  --option=<option>

#                 Select what to do if <file> already exists.

#                 Possible values are 'a', 'c', 'r' and 'n'.

#                 - a: append (starts with a separator)

#                 - c: continue (does not insert a seperator)

#                 - r: delete and restart

#                 - n: no log

#                 If no option is secified but <file> exists, an interactive selection is provided.

#             --quiet

#                 Suppress all messages.

#             <infile>

#                 Path of the wanted log file.

#             <outvar>

#                 Variable to store the path of the log file to.

# return:     0

#                 No error or warning occurred.

#             -1

#                 Error: invalid input

#

function setLogFile {

  local filepath=""

  local option=""

  local quiet=false

  # parse arguments

  local otherargs=()

  while [ $# -gt 0 ]; do

    if ( parseIsOption $1 ); then

      case "$1" in

        -o=*|--option=*)

          option=${1#*=}; shift 1;;

        -o*|--option*)

          option="$2"; shift 2;;

        -q|--quiet)

          quiet=true; shift 1;;

        *)

          printError "invalid option: $1\n"; shift 1;;

      esac

    else

      otherargs+=("$1")

      shift 1

    fi

  done

  filepath=$(realpath ${otherargs[0]})

  # if file already exists

  if [ -e $filepath ]; then

    # if no option was specified, ask what to do

    if [ -z "$option" ]; then

      printWarning "log file $filepath already esists\n"

      local userinput=""

      printf "Select what to do:\n"

      printf "  [A] - append log\n"

      printf "  [R] - restart log (delete existing file)\n"

      printf "  [N] - no log\n"

      readUserInput "AaRrNn" userinput

      option=${userinput,,}

    fi

    # evaluate option

    case "$option" in

      a|c)

        if [ $quiet = false ]; then

          printInfo "appending log to $filepath\n"

        fi

        if [ $option != c ]; then

          printf "\n" >> $filepath

          printf "######################################################################\n" >> $filepath

          printf "\n" >> $filepath

        fi

        ;;

      r)

        echo -n "" > $filepath

        if [ $quiet = false ]; then

          printInfo "content of $filepath wiped\n"

        fi

        ;;

      n)

        if [ $quiet = false ]; then

          printInfo "no log file will be generated\n"

        fi

        filepath=""

        ;;

      *) # sanity check (return error)

        printError "unexpected argument: $option\n"; return -1;;

    esac

  else

    if [ $quiet = false ]; then

      printInfo "log file set to $filepath\n"

    fi

  fi

  eval ${otherargs[1]}="$filepath"

  return 0

}

### check whether commands are available #######################################

# Checks whether the specified commands are available and can be executed.

#

# usage:      checkCommands [<command> <command> ...]

# arguments:  <command>

#                 Name of the command to check.

# return:     0

#                 All requested commands are available.

#             >0

#                 Number of requested commands that were not found.

#             -1

#                 No argument given.

#

function checkCommands {

  local status=0

  # return if no argument was specified

  if [ $# -eq 0 ]; then

    return -1

  fi

  # check all specified commands

  while [ $# -gt 0 ]; do

    command -v $1 &>/dev/null

    if [ $? -ne 0 ]; then

      printWarning "Command '$1' not available.\n"

      status=$((status + 1))

    fi

    shift 1

  done

  return $status

}

################################################################################

# SPECIFIC FUNCTIONS                                                           #

################################################################################

### print welcome text #########################################################

# Prints a welcome message to standard out.

#

# usage:      printWelcomeText

# arguments:  n/a

# return:     n/a

#

function printWelcomeText {

  printf "######################################################################\n"

  printf "#                                                                    #\n"

  printf "#              Welcome to the ChibiOS submodule setup!               #\n"

  printf "#                                                                    #\n"

  printf "######################################################################\n"

  printf "#                                                                    #\n"

  printf "# Copyright (c) 2016..2019  Thomas Schöpping                         #\n"

  printf "#                                                                    #\n"

  printf "# This is free software; see the source for copying conditions.      #\n"

  printf "# There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR  #\n"

  printf "# A PARTICULAR PURPOSE. The development of this software was         #\n"

  printf "# supported by the Excellence Cluster EXC 227 Cognitive Interaction  #\n"

  printf "# Technology. The Excellence Cluster EXC 227 is a grant of the       #\n"

  printf "# Deutsche Forschungsgemeinschaft (DFG) in the context of the German #\n"

  printf "# Excellence Initiative.                                             #\n"

  printf "#                                                                    #\n"

  printf "######################################################################\n"

}

### print help #################################################################

# Prints a help text to standard out.

#

# usage:      printHelp

# arguments:  n/a

# return:     n/a

#

function printHelp {

  printInfo "printing help text\n"

  printf "usage:    $(basename ${BASH_SOURCE[0]}) [-h|--help] [-i|--init] [-p|--patch] [-d|--documentation=<option>] [-w|--wipe] [-q|--quit] [--log=<file>]\n"

  printf "options:  -h, --help\n"

  printf "              Print this help text.\n"

  printf "          -i, --init\n"

  printf "              Initialize ChibiOS submodule.\n"

  printf "          -p, --patch,\n"

  printf "              Apply patches to ChibiOS.\n"

  printf "          -d, --documentation <option>\n"

  printf "              Possible options are: 'g' and 'o' (can be combined).\n"

  printf "              - g: Generate HTML documentation of ChibiOS.\n"

  printf "              - o: Open HTML documentation of ChibiOS.\n"

  printf "          -w, --wipe\n"

  printf "              Wipe ChibiOS submodule.\n"

  printf "          -q, --quit\n"

  printf "              Quit the script.\n"

  printf "          --log=<file>\n"

  printf "              Specify a log file.\n"

}

### initialize ChibiOS submodule ###############################################

# Initializes the ChibiOS Git submodule.

#

# usage:      initChibiOS

# arguments:  n/a

# return:     0

#                 No error or warning occurred.

#             1

#                 Warning: Aborted by user.

#             -1

#                 Error: Unexpected user input.

#             -1

#                 Error: Missing dependency.

#

function initChibiOS {

  printInfo "initializing ChibiOS submodule...\n"

  local userdir=$(pwd)

  local kerneldir=$(dirname $(realpath ${BASH_SOURCE[0]}))

  local chibiosdir=${kerneldir}/ChibiOS

  # if the kernel folder is not empty

  if [ ! -z "$(ls -A $chibiosdir)" ]; then

    printWarning "$chibiosdir is not empty. Delete and reinitialize? [y/n]\n"

    local userinput=""

    readUserInput "YyNn" userinput

    case "$userinput" in

      Y|y)

        wipeChibiOS

        ;;

      N|n)

        printWarning "ChibiOS initialization aborted by user\n"

        return 1

        ;;

      *) # sanity check (return error)

        printError "unexpected input: $userinput\n"; return -1;;

    esac

  fi

  # check dependencies

  checkCommands git

  if [ $? -ne 0 ]; then

    printError "Missing dependencies detected.\n"

    return -2

  fi

  # initialize submodule to default branch

  cd $kerneldir

  git submodule update --init $chibiosdir 2>&1 | tee -a $LOG_FILE

  while [ ${PIPESTATUS[0]} -ne 0 ]; do

    printWarning "initialitaion failed. Retry? [y/n]\n"

    local userinput=""

    readUserInput "YyNn" userinput

    case "$userinput" in

      Y|y)

        git submodule update --init $chibiosdir 2>&1 | tee -a $LOG_FILE;;

      N|n)

        printWarning "ChibiOS initialization aborted by user\n"

        cd $userdir

        return 1

        ;;

      *) # sanity check (return error)

        printError "unexpected input: $userinput\n"; return -1;;

    esac

  done

  cd $userdir

  return 0

}

### patch ChibiOS ##############################################################

# Applies patches to ChibiOS submodule.

#

# usage:      patchChibiOS

# arguments:  n/a

# return:     0

#                 No error or warning occurred.

#             1

#                 Warning: ChibiOS not initialized yet.

#             2

#                 Warning: Setup aborted by user.

#             -1

#                 Error: Unexpected user input.

#

function patchChibiOS {

  printInfo "applying patches to ChibiOS\n"

  local userdir=$(pwd)

  local kerneldir=$(dirname $(realpath ${BASH_SOURCE[0]}))

  local chibiosdir=${kerneldir}/ChibiOS

  local git_branch_patched="AMiRo-OS"

  # check dependencies

  checkCommands git

  if [ $? -ne 0 ]; then

    printError "Missing dependencies detected.\n"

    return -2

  fi

  # if the ChibiOS folder is empty

  if [ -z "$(ls -A $chibiosdir)" ]; then

    printWarning "$chibiosdir is empty. Please initialize first.\n"

    return 1

  else 

    # get some information from Git

    cd $chibiosdir

    local git_branch_current=$(git rev-parse --abbrev-ref HEAD)

    local git_branches=$(git for-each-ref --format="%(refname)")

    local git_dirtyfiles=($(git ls-files -dmo --exclude-standard --exclude=/doc))

    cd $userdir

    local issues=0

    # if the current branch is already $git_branch_patched

    if [ "$git_branch_current" = "$git_branch_patched" ]; then

      issues=$((issues + 1))

      printWarning "current branch is already $git_branch_patched\n"

    fi

    # if the current branch is bot $git_branch_patched, but another branch $git_branch_patched already exists

    if [ "$git_branch_current" != "$git_branch_patched" ] && [[ "$git_branches" = *"$git_branch_patched"* ]]; then

      issues=$((issues + 1))

      printWarning "another branch $git_branch_patched already exists\n"

    fi

    # if there are untracked, modified, or deleted files

    if [ ${#git_dirtyfiles[@]} != 0 ]; then

      issues=$((issues + 1))

      printWarning "there are ${#git_dirtyfiles[@]} untracked, modified, or deleted files\n"

    fi

    if [ $issues -gt 0 ]; then

      local userinput=""

      printWarning "$issues issues detected. Do you want to continue? [y/n]\n"

      readUserInput "YyNn" userinput

      case "$userinput" in

        Y|y)

          ;;

        N|n)

          printfWarning "ChibiOS patching aborted by user\n"

          return 2

          ;;

        *) # sanity check (return error)

          printError "unexpected input: $userinput\n"; return -1;;

      esac

    fi

    # create a new branch and apply the patches

    local patches=${kerneldir}/patches/*.patch

    cd $chibiosdir

    git checkout -b "$git_branch_patched" 2>&1 | tee -a $LOG_FILE

    for patch in $patches; do

      cp $patch .

      patch=$(basename $patch)

      printInfo "applying ${patch}...\n"

      git apply --whitespace=nowarn --ignore-space-change --ignore-whitespace < $patch 2>&1 | tee -a $LOG_FILE

      rm $patch

#      # These lines are disabled for safety reasons:

#      #   Filed commits are detected as valid changes by the super-project.

#      #   This may lead to errorneous updates of the super-project, as to point to one of these commit hashes.

#      #   Since these commits are not pushed upstream, initialization of the super-project will therefore fail, because

#      #   the referenced hashed (after patching) do not exist in a clean copy of this sub-project.

#      git add $(git ls-files -dmo --exclude-standard --exclude=/doc) $(git diff --name-only) 2>&1 | tee -a $LOG_FILE

#      git commit --message="$patch applied" 2>&1 | tee -a $LOG_FILE

    done

    cd $userdir

    return 0

  fi

}

### ChibiOS dcoumentation setup ################################################

#

# usage:      documentation [<option>]

# arguments:  <option>

#                 Can be either 'g' or 'o' to generate or open HTML documentation respectively.

# return:     0

#                 No error or warning occurred.

#             1

#                 Warning: Kernel not nitialized yet.

#             2

#                 Warning: Setup aborted by user.

#             3

#                 Warning: Issues occurred.

#             -1

#                 Error: Unexpected user input.

#             -2

#                 Error: Missing dependencies.

#

function documentation {

  local userdir=$(pwd)

  local kerneldir=$(dirname $(realpath ${BASH_SOURCE[0]}))

  local chibiosdir=${kerneldir}/ChibiOS

  # if the ChibiOS folder is empty

  if [ -z "$(ls -A $chibiosdir)" ]; then

    printWarning "$chibiosdir is empty. Please initialize first.\n"

    return 1

  else

    local option="";

    # if no argument was specified, ask what to do

    if [ $# -eq 0 ]; then

      printInfo "ChibiOS documentation setup\n"

      printf "Please select one of the following actions:\n"

      printf "  [G] - generate HTML documentation\n"

      printf "  [O] - open HTML documentation\n"

      printf "  [A] - abort this setup\n"

      local userinput

      readUserInput "GgOoAa" userinput

      option=${userinput,,}

      if [ $option = "a" ]; then

        printInfo "ChibiOS documentation setup aborted by user\n"

        return 2

      fi

    else

      option="$1"

    fi

    local issues=0

    case "$option" in

      # generate HTML documentation

      g)

        # check dependencies

        checkCommands doxygen

        if [ $? -ne 0 ]; then

          printError "Missing dependencies detected.\n"

          return -2

        fi

        # ChibiOS/HAL: check if required files exis

        if [ -f ${chibiosdir}/doc/hal/makehtml.sh ]; then

          printInfo "generating ChibiOS/HAL documentation...\n"

          cd ${chibiosdir}/doc/hal

          ${chibiosdir}/doc/hal/makehtml.sh 2>&1 | tee -a $LOG_FILE

          cd $userdir

          printInfo "access ChibiOS/HAL documentation via ${chibiosdir}doc/hal/html/index.html\n"

        else

          issues=$((issues + 1))

          printError "could not generate ChibiOS/HAL documentation\n"

        fi

        # ChibiOS/RT: check if required files exis

        if [ -f ${chibiosdir}/doc/rt/makehtml.sh ]; then

          printInfo "generating ChibiOS/RT documentation...\n"

          cd ${chibiosdir}/doc/rt

          ${chibiosdir}/doc/rt/makehtml.sh 2>&1 | tee -a $LOG_FILE

          cd $userdir

          printInfo "access ChibiOS/RT documentation via ${chibiosdir}doc/rt/html/index.html\n"

        else

          issues=$((issues + 1))

          printError "could not generate ChibiOS/RT documentation\n"

        fi

        # ChibiOS/NIL: check if required files exis

        if [ -f ${chibiosdir}/doc/nil/makehtml.sh ]; then

          printInfo "generating ChibiOS/NIL documentation...\n"

          cd ${chibiosdir}/doc/nil

          ${chibiosdir}/doc/nil/makehtml.sh 2>&1 | tee -a $LOG_FILE

          cd $userdir

          printInfo "access ChibiOS/NIL documentation via ${chibiosdir}edoc/nil/html/index.html\n"

        else

          issues=$((issues + 1))

          printError "could not generate ChibiOS/NIL documentation\n"

        fi

        ;;

      # open HTML documentation

      o)

        # ChibiOS/HAL: check if required files exis

        if [ -f ${chibiosdir}/doc/hal/html/index.html ]; then

          printInfo "open ChibiOS/HAL documentation\n"

          xdg-open ${chibiosdir}/doc/hal/html/index.html &> /dev/null &

        else

          issues=$((issues + 1))

          printError "could not open ChibiOS/HAL documentation\n"

        fi

        # ChibiOS/RT: check if required files exis

        if [ -f ${chibiosdir}/doc/rt/html/index.html ]; then

          printInfo "open ChibiOS/RT documentation\n"

          xdg-open ${chibiosdir}/doc/rt/html/index.html &> /dev/null &

        else

          issues=$((issues + 1))

          printError "could not open ChibiOS/RT documentation\n"

        fi

        # ChibiOS/NIL: check if required files exis

        if [ -f ${chibiosdir}/doc/nil/html/index.html ]; then

          printInfo "open ChibiOS/NIL documentation\n"

          xdg-open ${chibiosdir}/doc/nil/html/index.html &> /dev/null &

        else

          issues=$((issues + 1))

          printError "could not open ChibiOS/NIL documentation\n"

        fi

        ;;

      *) # sanity check (return error)

        printError "unexpected input: $userinput\n"; return -1;;

    esac

    if [ $issues -gt 0 ]; then

      return 3

    else

      return 0

    fi

  fi

}

### reset ChibiOS submodule and wipe directory #################################

# Resets the ChibiOS Git submodule and wipes the directory.

#

# usage:      wipeChibiOS

# arguments:  n/a

# return:     0

#                 No error or warning occurred.

#             1

#                 Warning: Submodule directory is already empty.

#             2

#                 Warning: Wiping aborted by user.

#             -1

#                 Error: Unexpected user input.

#

function wipeChibiOS {

  printInfo "reset and wipe Git submodule $kerneldir\n"

  local userdir=$(pwd)

  local kerneldir=$(dirname $(realpath ${BASH_SOURCE[0]}))

  local chibiosdir=${kerneldir}/ChibiOS

  local git_branch_patched="AMiRo-OS"

  # check dependencies

  checkCommands git

  if [ $? -ne 0 ]; then

    printError "Missing dependencies detected.\n"

    return -2

  fi

  # if the ChibiOS folder is empty

  if [ -z "$(ls -A $chibiosdir)" ]; then

    printInfo "$chibiosdir is alread empty\n"

    return 1

  else 

    # get some information from Git

    cd $kerneldir

    local git_basehash=($(git ls-tree -d HEAD $kerneldir)); git_basehash=${git_basehash[2]}

    cd $chibiosdir

    local git_branch_current=$(git rev-parse --abbrev-ref HEAD)

    local git_difftobase="$(git diff ${git_basehash}..HEAD)"

    local git_commits=$(git log --format=oneline ${git_basehash}..HEAD)

    local git_dirtyfiles=($(git ls-files -dmo --exclude-standard --exclude=/doc))

    cd $userdir

    local issues=0

    # if the HEAD is neither detached, nor is the current branch $git_branch_patched

    if [ "$git_branch_current" != "HEAD" ] && [ "$git_branch_current" != "$git_branch_patched" ]; then

      issues=$((issues + 1))

      printWarning "modifications to ChibiOS Git submodule detected\n"

    fi

    # if HEAD is ahead of submodule base commit but with more than just applied patches

    if [ -n "$git_difftobase" ] && [ -n "$(echo $git_commits | grep -Ev '\.patch applied$')" ]; then

      issues=$((issues + 1))

      printWarning "HEAD is ahead of submodule base by unexpected commits\n"

    fi

    # if there are untracked, modified, or deleted files

    if [ ${#git_dirtyfiles[@]} != 0 ]; then

      issues=$((issues + 1))

      printWarning "there are ${#git_dirtyfiles[@]} untracked, modified, or deleted files\n"

    fi

    if [ $issues -gt 0 ]; then

      local userinput=""

      printWarning "$issues issues detected. Do you want to continue? [y/n]\n"

      readUserInput "YyNn" userinput

      case "$userinput" in

        Y|y)

          ;;

        N|n)

          printfWarning "wiping ChibiOS Git submodule aborted by user\n"

          return 2

          ;;

        *) # sanity check (return error)

          printError "unexpected input: $userinput\n"; return -1;;

      esac

    fi

    # checkout base commit and delete all local branches

    cd $kerneldir

    git submodule update --force --checkout $kerneldir | tee -a $LOG_FILE

    cd $chibiosdir

    local git_branches=($(git for-each-ref --format="%(refname)"))

    for branch in $git_branches; do

      if [[ $branch = *"heads/"* ]]; then

        git branch -D ${branch##*/} | tee -a $LOG_FILE

      fi

    done

    cd $userdir

    # deinitialize ChibiOS submodule and delete any remaining files

    cd $kerneldir

    git submodule deinit -f $chibiosdir 2>&1 | tee -a $LOG_FILE

    rm -rf $chibiosdir/*

    cd $userdir

    return 0

  fi

}

### main function of this script ###############################################

# The kernel setup provides comfortable initialization, patching, documentation

# generation and cleanup for ChibiOS.

#

# usage:      see function printHelp

# arguments:  see function printHelp

# return:     0

#                 No error or warning occurred.

#

function main {

  # print welcome/info text if not suppressed

  if [[ $@ != *"--noinfo"* ]]; then

    printWelcomeText

  else

    printf "######################################################################\n"

  fi

  printf "\n"

  # if --help or -h was specified, print the help text and exit

  if [[ $@ == *"--help"* || $@ == *"-h"* ]]; then

    printHelp

    printf "\n"

    quitScript

  fi

  # set log file if specified

  if [[ $@ == *"--log"* ]] || [[ $@ == *"--LOG"* ]]; then

    # get the parameter (file name)

    local cmdidx=1

    while [[ ! "${!cmdidx}" = "--log"* ]] && [[ ! "${!cmdidx}" = "--LOG"* ]]; do

      cmdidx=$[cmdidx + 1]

    done

    local cmd="${!cmdidx}"

    local logfile=""

    if [[ "$cmd" = "--log="* ]] || [[ "$cmd" = "--LOG="* ]]; then

      logfile=${cmd#*=}

    else

      local filenameidx=$((cmdidx + 1))

      logfile="${!filenameidx}"

    fi

    # optionally force silent appending

    if [[ "$cmd" = "--LOG"* ]]; then

      setLogFile --option=c --quiet "$logfile" LOG_FILE

    else

      setLogFile "$logfile" LOG_FILE

      printf "\n"

    fi

  fi

  # log script name

  printLog "this is $(realpath ${BASH_SOURCE[0]})\n"

  # parse arguments

  local otherargs=()

  while [ $# -gt 0 ]; do

    if ( parseIsOption $1 ); then

      case "$1" in

        -h|--help) # already handled; ignore

          shift 1;;

        -i|--init)

           initChibiOS; printf "\n"; shift 1;;

        -p|--patch)

           patchChibiOS; printf "\n"; shift 1;;

        -d=*|--documentation=*)

           documentation "${1#*=}"; printf "\n"; shift 1;;

        -d|--documentation)

           if ( ! parseIsOption $2 ); then

             documentation "$2"; printf "\n"; shift 2

           else

             documentation; printf "\n"; shift 1

           fi;;

        -w|--wipe)

          wipeChibiOS; printf "\n"; shift 1;;

        -q|--quit)

          quitScript; shift 1;;

        --log=*|--LOG=*) # already handled; ignore

          shift 1;;

        --log|--LOG) # already handled; ignore

          shift 2;;

        --noinfo) # already handled; ignore

          shift 1;;

        *)

          printError "invalid option: $1\n"; shift 1;;

      esac

    else

      otherargs+=("$1")

      shift 1

    fi

  done

  # interactive menu

  while ( true ); do

    # main menu info prompt and selection

    printInfo "ChibiOS kernel setup main menu\n"

    printf "Please select one of the following actions:\n"

    printf "  [I] - initialize ChibiOS submodule\n"

    printf "  [P] - apply patches to ChibiOS\n"

    printf "  [D] - generate or open HTML documentation\n"

    printf "  [W] - wipe ChibiOS submodule\n"

    printf "  [Q] - quit this setup\n"

    local userinput=""

    readUserInput "IiPpDdWwQq" userinput

    printf "\n"

    # evaluate user selection

    case "$userinput" in

      I|i)

        initChibiOS; printf "\n";;

      P|p)

        patchChibiOS; printf "\n";;

      D|d)

        documentation; printf "\n";;

      W|w)

        wipeChibiOS; printf "\n";;

      Q|q)

        quitScript;;

      *) # sanity check (exit with error)

        printError "unexpected argument: $userinput\n";;

    esac

  done

  exit 0

}

################################################################################

# SCRIPT ENTRY POINT                                                           #

################################################################################

main "$@"