#!/bin/bash
# -*- mode: shell-script; indent-tabs-mode: nil; sh-basic-offset: 4; -*-
# ex: ts=8 sw=4 sts=4 et filetype=sh
# 
# Generator script for a dracut initramfs
# Tries to retain some degree of compatibility with the command line
# of the various mkinitrd implementations out there
#

# Copyright 2005-2010 Red Hat, Inc.  All rights reserved.
#
# 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 2 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/>.
#

# store for logging
dracut_args="$@"

usage() {
#                                                       80x25 linebreak here ^
    cat << EOF
Usage: $0 [OPTION]... <initramfs> <kernel-version>
Creates initial ramdisk images for preloading modules

  -f, --force           Overwrite existing initramfs file.
  -m, --modules [LIST]  Specify a space-separated list of dracut modules to
                         call when building the initramfs. Modules are located
                         in /usr/share/dracut/modules.d.
  -o, --omit [LIST]     Omit a space-separated list of dracut modules.
  -a, --add [LIST]      Add a space-separated list of dracut modules.
  -d, --drivers [LIST]  Specify a space-separated list of kernel modules to
                        exclusively include in the initramfs.
  --add-drivers [LIST]  Specify a space-separated list of kernel 
                        modules to add to the initramfs.
  --filesystems [LIST]  Specify a space-separated list of kernel filesystem
                        modules to exclusively include in the generic
                        initramfs.
  -k, --kmoddir [DIR]   Specify the directory, where to look for kernel 
                        modules
  --fwdir [DIR]         Specify additional directories, where to look for 
                        firmwares, separated by :
  --kernel-only         Only install kernel drivers and firmware files
  --no-kernel           Do not install kernel drivers and firmware files
  --strip               Strip binaries in the initramfs
  --nostrip             Do not strip binaries in the initramfs (default)
  --mdadmconf           Include local /etc/mdadm.conf
  --nomdadmconf         Do not include local /etc/mdadm.conf
  --lvmconf             Include local /etc/lvm/lvm.conf
  --nolvmconf           Do not include local /etc/lvm/lvm.conf
  -h, --help            This message
  --debug               Output debug information of the build process
  -L, --stdlog [0-6]    Specify logging level (to standard error)
                         0 - suppress any messages
                         1 - only fatal errors
                         2 - all errors
                         3 - warnings
                         4 - info (default)
                         5 - debug info (here starts lots of output)
                         6 - trace info (and even more)
  -v, --verbose         Increase verbosity level (default is info(4))
  -q, --quiet           Decrease verbosity level (default is info(4))
  -c, --conf [FILE]     Specify configuration file to use.
                         Default: /etc/dracut.conf
  --confdir [DIR]       Specify configuration directory to use *.conf files 
                         from. Default: /etc/dracut.conf.d
  -l, --local           Local mode. Use modules from the current working
                         directory instead of the system-wide installed in
                         /usr/share/dracut/modules.d.
                         Useful when running dracut from a git checkout.
  -H, --hostonly        Host-Only mode: Install only what is needed for
                         booting the local host instead of a generic host.
  --fstab               Use /etc/fstab to determine the root device.
  -i, --include [SOURCE] [TARGET]
                        Include the files in the SOURCE directory into the
                         Target directory in the final initramfs.
                        If SOURCE is a file, it will be installed to TARGET 
                         in the final initramfs.
  -I, --install [LIST]  Install the space separated list of files into the
                         initramfs.
  --gzip                Compress the generated initramfs using gzip.
                         This will be done by default, unless another
                         compression option or --no-compress is passed.
  --bzip2               Compress the generated initramfs using bzip2.
                         Make sure your kernel has bzip2 decompression support
                         compiled in, otherwise you will not be able to boot.
  --lzma                Compress the generated initramfs using lzma.
                         Make sure your kernel has lzma support compiled in, 
                         otherwise you will not be able to boot.
  --xz                  Compress the generated initramfs using xz.
                         Make sure that your kernel has xz support compiled
                         in, otherwise you will not be able to boot.
  --compress [COMPRESSION] Compress the generated initramfs with the
                         passed compression program.  Make sure your kernel
                         knows how to decompress the generated initramfs, 
                         otherwise you will not be able to boot.
  --no-compress         Do not compress the generated initramfs.  This will
                         override any other compression options.
  --list-modules        List all available dracut modules.
  -M, --show-modules    Print included module's name to standard output during
                         build.
EOF
}

# function push()
# push values to a stack
# $1 = stack variable
# $2.. values
# example:
# push stack 1 2 "3 4"
push() {
    local __stack=$1; shift
    for i in "$@"; do
        eval ${__stack}'[${#'${__stack}'[@]}]="$i"'
    done
}

# function pop()
# pops the last value from a stack
# assigns value to second argument variable
# or echo to stdout, if no second argument
# $1 = stack variable
# $2 = optional variable to store the value
# example:
# pop stack val
# val=$(pop stack)
pop() {
    local __stack=$1; shift
    local __resultvar=$1    
    local myresult;
    # check for empty stack
    eval '[[ ${#'${__stack}'[@]} -eq 0 ]] && return 1'

    eval myresult='${'${__stack}'[${#'${__stack}'[@]}-1]}'

    if [[ "$__resultvar" ]]; then
        eval $__resultvar="'$myresult'"
    else
        echo "$myresult"
    fi
    eval unset ${__stack}'[${#'${__stack}'[@]}-1]'
    return 0
}

# Little helper function for reading args from the commandline.
# it automatically handles -a b and -a=b variants, and returns 1 if
# we need to shift $3.
read_arg() {
    # $1 = arg name
    # $2 = arg value
    # $3 = arg parameter
    local rematch='^[^=]*=(.*)$'
    if [[ $2 =~ $rematch ]]; then
        read "$1" <<< "${BASH_REMATCH[1]}"
    else
        read "$1" <<< "$3"
        # There is no way to shift our callers args, so
        # return 1 to indicate they should do it instead.
        return 1
    fi
}

# Little helper function for reading args from the commandline to a stack.
# it automatically handles -a b and -a=b variants, and returns 1 if
# we need to shift $3.
push_arg() {
    # $1 = arg name
    # $2 = arg value
    # $3 = arg parameter
    local rematch='^[^=]*=(.*)$'
    if [[ $2 =~ $rematch ]]; then
        push "$1" "${BASH_REMATCH[1]}"
    else
        push "$1" "$3"
        # There is no way to shift our callers args, so
        # return 1 to indicate they should do it instead.
        return 1
    fi
}

verbosity_mod_l=0

while (($# > 0)); do
    case ${1%%=*} in
        -a|--add)      push_arg add_dracutmodules_l  "$@" || shift;;
        --add-drivers) push_arg add_drivers_l        "$@" || shift;;
        -m|--modules)  push_arg dracutmodules_l      "$@" || shift;;
        -o|--omit)     push_arg omit_dracutmodules_l "$@" || shift;;
        -d|--drivers)  push_arg drivers_l            "$@" || shift;;
        --filesystems) push_arg filesystems_l        "$@" || shift;;
        -I|--install)  push_arg install_items        "$@" || shift;;
        --fwdir)       push_arg fw_dir_l             "$@" || shift;;
        -k|--kmoddir)  read_arg drivers_dir_l        "$@" || shift;;
        -c|--conf)     read_arg conffile             "$@" || shift;;
        --confdir)     read_arg confdir              "$@" || shift;;
        -L|--stdlog)   read_arg stdloglvl_l          "$@" || shift;;
        -I|--install)  read_arg install_items        "$@" || shift;;
        --fwdir)       read_arg fw_dir_l             "$@" || shift;;
        --compress)    read_arg compress_l           "$@" || shift;;
        -f|--force)    force=yes;;
        --kernel-only) kernel_only="yes"; no_kernel="no";;
        --no-kernel)   kernel_only="no"; no_kernel="yes";;
        --strip)       do_strip_l="yes";;
        --nostrip)     do_strip_l="no";;
        --mdadmconf)   mdadmconf_l="yes";;
        --nomdadmconf) mdadmconf_l="no";;
        --lvmconf)     lvmconf_l="yes";;
        --nolvmconf)   lvmconf_l="no";;
        --debug)       debug="yes";;
        -v|--verbose)  ((verbosity_mod_l++));;
        -q|--quiet)    ((verbosity_mod_l--));;
        -l|--local)    allowlocal="yes" ;;
        -H|--hostonly) hostonly_l="yes" ;;
        --fstab)       use_fstab_l="yes" ;;
        -h|--help)     usage; exit 1 ;;
        -i|--include)  push include_src "$2"
                       push include_target "$3"
                       shift 2;;
        --bzip2)       compress_l="bzip2";;
        --lzma)        compress_l="lzma";;
        --xz)          compress_l="xz";;
        --no-compress) _no_compress_l="cat";;
        --gzip)        compress_l="gzip";;
        --list-modules)
            do_list="yes";
            ;;
        -M|--show-modules)
                       show_modules_l="yes"
                       ;;
        -*) printf "\nUnknown option: %s\n\n" "$1" >&2; usage; exit 1;;
        *) 
            if ! [[ ${outfile+x} ]]; then
                outfile=$1
            elif ! [[ ${kernel+x} ]]; then
                kernel=$1
            else
                usage; exit 1;
            fi
            ;;
    esac
    shift
done
if ! [[ $kernel ]]; then
    kernel=$(uname -r)
fi
[[ $outfile ]] || outfile="/boot/initramfs-$kernel.img"

PATH=/sbin:/bin:/usr/sbin:/usr/bin
export PATH

[[ $debug ]] && { 
    export PS4='${BASH_SOURCE}@${LINENO}(${FUNCNAME[0]}): ';
    set -x
}

[[ $dracutbasedir ]] || dracutbasedir=/usr/share/dracut

[[ $allowlocal && -f "$(readlink -f ${0%/*})/dracut-functions" ]] && \
    dracutbasedir="$(readlink -f ${0%/*})" 

# if we were not passed a config file, try the default one
if [[ ! -f $conffile ]]; then
    [[ $allowlocal ]] && conffile="$dracutbasedir/dracut.conf" || \
        conffile="/etc/dracut.conf"
fi

if [[ ! -d $confdir ]]; then
    [[ $allowlocal ]] && confdir="$dracutbasedir/dracut.conf.d" || \
        confdir="/etc/dracut.conf.d"
fi

# source our config file
[[ -f $conffile ]] && . "$conffile"

# source our config dir
if [[ $confdir && -d $confdir ]]; then
    for f in "$confdir"/*.conf; do 
        [[ -e $f ]] && . "$f"
    done
fi

# these optins add to the stuff in the config file
if (( ${#add_dracutmodules_l[@]} )); then
    while pop add_dracutmodules_l val; do
        add_dracutmodules+=" $val "
    done
fi

if (( ${#add_drivers_l[@]} )); then
    while pop add_drivers_l val; do
        add_drivers+=" $val "
    done
fi

# these options override the stuff in the config file
if (( ${#dracutmodules_l[@]} )); then
    dracutmodules=''
    while pop dracutmodules_l val; do
        dracutmodules+="$val "
    done
fi

if (( ${#omit_dracutmodules_l[@]} )); then
    omit_dracutmodules=''
    while pop omit_dracutmodules_l val; do
        omit_dracutmodules+="$val "
    done
fi

if (( ${#drivers_l[@]} )); then
    drivers=''
    while pop drivers_l val; do
        drivers+="$val "
    done
fi

if (( ${#filesystems_l[@]} )); then
    filesystems=''
    while pop filesystems_l val; do
        filesystems+="$val "
    done
fi

if (( ${#fw_dir_l[@]} )); then
    fw_dir=''
    while pop fw_dir_l val; do
        fw_dir+="$val "
    done
fi

[[ $stdloglvl_l ]] && stdloglvl=$stdloglvl_l
[[ ! $stdloglvl ]] && stdloglvl=4
stdloglvl=$((stdloglvl + verbosity_mod_l))
((stdloglvl > 6)) && stdloglvl=6
((stdloglvl < 0)) && stdloglvl=0

[[ $drivers_dir_l ]] && drivers_dir=$drivers_dir_l
[[ $do_strip_l ]] && do_strip=$do_strip_l
[[ $hostonly_l ]] && hostonly=$hostonly_l
[[ $use_fstab_l ]] && use_fstab=$use_fstab_l
[[ $mdadmconf_l ]] && mdadmconf=$mdadmconf_l
[[ $lvmconf_l ]] && lvmconf=$lvmconf_l
[[ $dracutbasedir ]] || dracutbasedir=/usr/share/dracut
[[ $fw_dir ]] || fw_dir="/lib/firmware/updates /lib/firmware"
[[ $do_strip ]] || do_strip=no
[[ $compress_l ]] && compress=$compress_l
[[ $show_modules_l ]] && show_modules=$show_modules_l
# eliminate IFS hackery when messing with fw_dir
fw_dir=${fw_dir//:/ }

# handle compression options.
case $compress in
    bzip2) compress="bzip -9";;
    lzma)  compress="lzma -9";;
    xz)    compress="xz --check=crc32 --lzma2=dict=1MiB";;
    gzip)  type pigz > /dev/null 2>&1 && compress="pigz -9" || \
                                         compress="gzip -9";;
esac
if [[ $_no_compress_l = "cat" ]]; then
    compress="cat"
fi

[[ $hostonly = yes ]] && hostonly="-h"
[[ $hostonly != "-h" ]] && unset hostonly
[[ $compress ]] || compress="gzip -9"

if [[ -f $dracutbasedir/dracut-functions ]]; then
    . $dracutbasedir/dracut-functions
else
    echo "Cannot find $dracutbasedir/dracut-functions." >&2
    echo "Are you running from a git checkout?" >&2
    echo "Try passing -l as an argument to $0" >&2
    exit 1
fi

dracutfunctions=$dracutbasedir/dracut-functions
export dracutfunctions

ddebug "Executing $0 $dracut_args"

[[ $do_list = yes ]] && {
    for mod in $dracutbasedir/modules.d/*; do
        [[ -d $mod ]] || continue;
        [[ -e $mod/install || -e $mod/installkernel || \
            -e $mod/module-setup.sh ]] || continue
        echo ${mod##*/??}
    done
    exit 0
}

# Detect lib paths
[[ $libdir ]] || for libdir in /lib64 /lib; do
    [[ -d $libdir ]] && break
done || {
    dfatal 'No lib directory?!!!'
    exit 1
}

[[ $usrlibdir ]] || for usrlibdir in /usr/lib64 /usr/lib; do
    [[ -d $usrlibdir ]] && break
done || dwarn 'No usr/lib directory!'

# This is kinda legacy -- eventually it should go away.
case $dracutmodules in
    ""|auto) dracutmodules="all" ;;
esac

abs_outfile=$(readlink -f "$outfile") && outfile="$abs_outfile"

srcmods="/lib/modules/$kernel/"
[[ $drivers_dir ]] && {
    if vercmp $(modprobe --version | cut -d' ' -f3) lt 3.7; then
        dfatal 'To use --kmoddir option module-init-tools >= 3.7 is required.'
        exit 1
    fi
    srcmods="$drivers_dir"
}
export srcmods

if [[ -f $outfile && ! $force ]]; then
    dfatal "Will not override existing initramfs ($outfile) without --force"
    exit 1
fi

outdir=${outfile%/*}
[[ $outdir ]] || outdir="/"

if [[ ! -d "$outdir" ]]; then
    dfatal "Can't write $outfile: Directory $outdir does not exist."
    exit 1
elif [[ ! -w "$outdir" ]]; then
    dfatal "No permission to write $outdir."
    exit 1
elif [[ -f "$outfile" && ! -w "$outfile" ]]; then
    dfatal "No permission to write $outfile."
    exit 1
fi

[[ $TMPDIR && ! -w $TMPDIR ]] && unset TMPDIR
readonly initdir=$(mktemp -d -t initramfs.XXXXXX)

# clean up after ourselves no matter how we die.
trap 'ret=$?;rm -rf "$initdir";exit $ret;' EXIT 
# clean up after ourselves no matter how we die.
trap 'exit 1;' SIGINT 

# Need to be able to have non-root users read stuff (rpcbind etc)
chmod 755 "$initdir"

export initdir dracutbasedir dracutmodules drivers \
    fw_dir drivers_dir debug no_kernel kernel_only \
    add_drivers mdadmconf lvmconf filesystems \
    use_fstab libdir usrlibdir \
    stdloglvl sysloglvl fileloglvl kmsgloglvl logfile \
    debug

if [[ $kernel_only != yes ]]; then
    # Create some directory structure first
    for d in bin sbin usr/bin usr/sbin usr/lib etc \
        proc sys sysroot tmp dev/pts var/run; do 
        inst_dir "/$d"; 
    done
fi

# check all our modules to see if they should be sourced.
# This builds a list of modules that we will install next.
check_module_dir

# source our modules.
for moddir in "$dracutbasedir/modules.d"/[0-9][0-9]*; do
    mod=${moddir##*/}; mod=${mod#[0-9][0-9]}
    if strstr "$mods_to_load" " $mod "; then
        [[ $show_modules = yes ]] && echo "$mod" || \
            dinfo "*** Including module: $mod ***"
        if [[ $kernel_only = yes ]]; then
            module_installkernel $mod
        else
            module_install $mod
            if [[ $no_kernel != yes ]]; then
                module_installkernel $mod
            fi
        fi
        mods_to_load=${mods_to_load// $mod /}
    fi
done
unset moddir
dinfo "*** Including modules done ***"

## final stuff that has to happen

# generate module dependencies for the initrd
if [[ -d $initdir/lib/modules/$kernel ]] && \
    ! depmod -a -b "$initdir" $kernel; then
    dfatal "\"depmod -a $kernel\" failed."
    exit 1
fi

while pop include_src src && pop include_target tgt; do
    if [[ $src && $tgt ]]; then
        if [[ -f $src ]]; then
            inst $src $tgt
        else
            ddebug "Including directory: $src"
            mkdir -p "${initdir}/${tgt}"
            cp -a -t "${initdir}/${tgt}" "$src"/*
        fi
    fi
done

while pop install_items items; do
    for item in $items; do
        dracut_install "$item"
    done
done
unset item

# make sure that library links are correct and up to date
dracut_install /etc/ld.so.conf /etc/ld.so.conf.d/*
if ! ldconfig -r "$initdir"; then
    if [[ $UID = 0 ]]; then
        derror "ldconfig exited ungracefully"
    else
        derror "ldconfig might need uid=0 (root) for chroot()"
    fi
fi

if (($maxloglvl >= 5)); then
    ddebug "Listing sizes of included files:"
    du -c "$initdir" | sort -n | ddebug
fi

# strip binaries 
if [[ $do_strip = yes ]] ; then
    for p in strip grep find; do 
        if ! type -P $p >/dev/null; then
            derror "Could not find '$p'. You should run $0 with '--nostrip'."
            do_strip=no
        fi
    done
fi

if [[ $do_strip = yes ]] ; then
    for f in $(find "$initdir" -type f \
        \( -perm -0100 -or -perm -0010 -or -perm -0001 \
           -or -path '*/lib/modules/*.ko' \) ); do
        dinfo "Stripping $f"
        strip -g "$f" 2>/dev/null|| :
    done
fi

type hardlink &>/dev/null && {
    hardlink "$initdir" 2>&1
}

if ! ( cd "$initdir"; find . |cpio -R 0:0 -H newc -o --quiet | \
    $compress > "$outfile"; ); then 
    dfatal "dracut: creation of $outfile failed"
    exit 1
fi 

dinfo "Wrote $outfile:"
dinfo "$(ls -l "$outfile")"

exit 0