#!/bin/sh
#
# Deal with copying the FL2 file from and to the ISO image
#

# All the bios update iso images I have checked have had a fat16 filesystem
# embedded in a dos mbr image as the el-torito ISO payload.  They also all
# had the same offset to this fat filesystem, so hardcode that offset here.
# The offset value is bytes in decimal.
# TODO - one day, this offset will be wrong.  (geteltorito could be taught
# to output the starting sector it found as a starting point)
FAT_OFFSET=71680

DIR="$1"
case "$DIR" in
    from_iso) ;;
    to_iso)   ;;
    *)
        echo direction is either from_iso or to_iso
        exit 1
        ;;
esac
shift

ISO="$1"
if [ ! -e "$ISO" ]; then
    echo iso file must exist
    exit 1
fi
shift

# The "external" filename - used in the linux filesystem
FILENAME="$1"
if [ -z "$FILENAME" ]; then
    echo need linux filename
    exit 1
fi
shift

# The "internal" filename pattern to match - used in the BIOS update image
INTPATTERN="$1"
if [ -z "$INTPATTERN" ]; then
    echo need to specify the pattern to match the internal filenames with
    exit 1
fi


MATCH=$(mdir -i "$ISO"@@"$FAT_OFFSET" -/ -b |grep "$INTPATTERN")
if [ -z "$MATCH" ]; then
    echo "Error: could not find any files in $ISO matching $INTPATTERN"
    exit 1
fi
if [ $(echo "$MATCH" |wc -w) -ne 1 ]; then
    echo "Error: $ISO has more than one matching file:"
    echo "$MATCH"
    exit 1
fi

from_iso() {
    mcopy -n -i "$ISO"@@"$FAT_OFFSET" "$MATCH" "$FILENAME"
}

to_iso() {
    if [ ! -f "$FILENAME" ]; then
        echo "Error: $FILENAME must exist"
        exit 1
    fi
    mcopy -m -o -i "$ISO"@@"$FAT_OFFSET" "$FILENAME" "$MATCH"
}

$DIR