initrd/init:setup_onepupdrv() - Tahrpup

setup_onepupdrv() { #Line 360 of initrd/init
# "$1" - sfs spec - ex: sdb2,ext4,/pup/mydrv-1.2.3.sfs
# "$2" - suffix for "pup_" branch directory - ex: a
# "$3" - prepend after rw layer indicator - ex: p
 ONE_LAYER=""
 [ "$1" ] || return 1
 [ "$2" ] || return 1
 ONE_PART="$(echo "${1}" | cut -f 1 -d ',')"
 [ "$ONE_PART" ] || return 1
 ONE_REL_FN="$(echo "${1}" | cut -f 3 -d ',')"
 [ "$ONE_REL_FN" ] || return 1
 ONE_SFX="${2}"
 ONE_PREP="${3}"
 if [ "$ONE_PART" = "rootfs" ];then #humongous initrd.
  ONE_MP="" #actually it's '/'.
  COPY2RAM='yes' #actually it is already in ram, but load_sfs_file code puts it in a tmpfs.
 else
  if [ "$ONE_PART" = "$P_PART" ];then
   ONE_MP="$P_MP"
  else
   ONE_MP="$(mount | grep -m1 "/dev/$ONE_PART " | cut -f 3 -d ' ')"
   [ "$ONE_MP" ] || return 2
  fi
 fi
 ONE_FN="${ONE_MP}${ONE_REL_FN}"
 ONE_BASENAME="$(basename $ONE_REL_FN)"
 #validate sfs here
 [ -s "$ONE_FN" ] || return 3 #sfs not Ok
 load_sfs_file
 [ "$ONE_LAYER" ] || return 4 #sfs mount failed
 if [ "$ONE_PREP" ];then
  echo "mount -o remount,add:1:$ONE_LAYER /pup_new" #debug
  mount -o remount,add:1:$ONE_LAYER /pup_new
  [ $? -eq 0 ] || return 5
 else
  echo "mount -o remount,append:$ONE_LAYER /pup_new" #debug
  mount -o remount,append:$ONE_LAYER /pup_new
  [ $? -eq 0 ] || return 5
 fi
 NEWUNIONRECORD="${NEWUNIONRECORD}${ONE_BASENAME} "
 return 0
}