#!/ventoy/busybox/sh
#************************************************************************************
# Copyright (c) 2020, longpanda <admin@ventoy.net>
# 
# 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/>.
# 
#************************************************************************************


###################################################################
#                                                                  #
# Step 1 : parse kernel debug parameter                            #
#                                                                  #
####################################################################
mkdir /proc; mount -t proc proc /proc
vtcmdline=$(cat /proc/cmdline)
vtkerver=$(cat /proc/version)
umount /proc; rm -rf /proc

echo "kenel version=$vtkerver" >>$VTLOG
echo "kenel cmdline=$vtcmdline" >>$VTLOG

#break here for debug
if [ "$VTOY_BREAK_LEVEL" = "01" ] || [ "$VTOY_BREAK_LEVEL" = "11" ]; then
    sleep 5
    echo -e "\n\n\033[32m ################################################# \033[0m"
    echo -e "\033[32m ################ VENTOY DEBUG ################### \033[0m"
    echo -e "\033[32m ################################################# \033[0m \n"
    
    if [ "$VTOY_BREAK_LEVEL" = "11" ]; then
        cat $VTLOG
    fi
    exec $BUSYBOX_PATH/sh
fi


####################################################################
#                                                                  #
# Step 2 : extract real initramfs to /                             #
#                                                                  #
####################################################################
cd /
rm -rf /init /linuxrc /sbin /dev/  /root

ventoy_is_initrd_ramdisk() {
    #As I known, PCLinuxOS use ramdisk
    if echo $vtkerver | grep -i -q 'PCLinuxOS'; then
        true
    else
        false
    fi
}

# param: file skip magic tmp
ventoy_unpack_initramfs() {        
    vtfile=$1; vtskip=$2; vtmagic=$3; vttmp=$4    
    echo "=====ventoy_unpack_initramfs: #$*#" >> $VTLOG
    
    for vtx in '1F8B zcat' '1F9E zcat' '425A bzcat' '5D00 lzcat' 'FD37 xzcat' '894C lzopcat' '0221 lz4cat' '28B5 zstdcat' '3037 cat'; do
        if [ "${vtx:0:4}" = "${vtmagic:0:4}" ]; then
            echo "vtx=$vtx" >> $VTLOG            
            if [ $vtskip -eq 0 ]; then
                ${vtx:5} $vtfile | (cpio -idm 2>>$VTLOG; cat > $vttmp)
            else
                dd if=$vtfile skip=$vtskip iflag=skip_bytes status=none | ${vtx:5} | (cpio -idm 2>>$VTLOG; cat > $vttmp)
            fi
            break
        fi
    done
}

# param: file magic tmp
ventoy_unpack_initrd() {        
    vtfile=$1; vtmagic=$2; vttmp=$3    
    echo "=====ventoy_unpack_initrd: #$*#" >> $VTLOG
    
    for vtx in '1F8B zcat' '1F9E zcat' '425A bzcat' '5D00 lzcat' 'FD37 xzcat' '894C lzopcat' '0221 lz4cat' '28B5 zstdcat' '3037 cat'; do
        if [ "${vtx:0:4}" = "${vtmagic:0:4}" ]; then
            echo "vtx=$vtx" >> $VTLOG            
            ${vtx:5} $vtfile > $vttmp
            break
        fi
    done    
}


# This export is for busybox cpio command
export EXTRACT_UNSAFE_SYMLINKS=1

for vtfile in $(ls /initrd*); do    
    #decompress first initrd
    vtmagic=$(hexdump -n 2 -e '2/1 "%02X"' $vtfile)

    if ventoy_is_initrd_ramdisk; then
        ventoy_unpack_initrd $vtfile $vtmagic ${vtfile}_tmp
        mv ${vtfile}_tmp $vtfile
        break
    else
        ventoy_unpack_initramfs $vtfile 0 $vtmagic ${vtfile}_tmp
    fi

    #only for cpio,cpio,...,initrd sequence, initrd,cpio or initrd,initrd sequence is not supported
    while [ -e ${vtfile}_tmp ] && [ $(stat -c '%s' ${vtfile}_tmp) -gt 512 ]; do
        mv ${vtfile}_tmp $vtfile
        vtdump=$(hexdump -n 512 -e '512/1 "%02X"' $vtfile)
        vtmagic=$(echo $vtdump | sed 's/^\(00\)*//')
        let vtoffset="(${#vtdump}-${#vtmagic})/2"
        
        if [ -z "$vtmagic" ]; then
            echo "terminate with all zero data file" >> $VTLOG
            break
        fi
        
        ventoy_unpack_initramfs $vtfile $vtoffset ${vtmagic:0:4} ${vtfile}_tmp
    done
    
    rm -f $vtfile ${vtfile}_tmp
done


#break here for debug
if [ "$VTOY_BREAK_LEVEL" = "02" ] || [ "$VTOY_BREAK_LEVEL" = "12" ]; then
    sleep 5
    echo -e "\n\n\033[32m ################################################# \033[0m"
    echo -e "\033[32m ################ VENTOY DEBUG ################### \033[0m"
    echo -e "\033[32m ################################################# \033[0m \n"   
    if [ "$VTOY_BREAK_LEVEL" = "12" ]; then 
        cat $VTOY_PATH/log
    fi    
    exec $BUSYBOX_PATH/sh
fi


####################################################################
#                                                                  #
# Step 3 : Hand over to ventoy.sh                                  #
#                                                                  #
####################################################################
echo "Now hand over to ventoy.sh" >>$VTLOG
. $VTOY_PATH/tool/vtoytool_install.sh

export PATH=$VTOY_ORG_PATH
exec $BUSYBOX_PATH/sh $VTOY_PATH/ventoy.sh