motorola: Import star extract script

imported from https://github.com/HemanthJabalpuri/star
at e77390046256de0c4044fa480b2815011a3fa8ed

Change-Id: Iea4cdd8655d3aab9cfd3e55bdcafdba072b90462

motorola/star.sh

@@ -0,0 +1,46 @@
+#!/bin/sh
+
+# SPDX-License-Identifier: CC0-1.0
+
+# This basic program is used for unpacking Motorola archives which are made using single image tar(star) utility
+# can run in dash. dd, od, tr are used mainly(busybox also compatible)
+#
+# Created : 1st Feb 2023
+# Author  : HemanthJabalpuri
+
+if [ $# -lt 2 ]; then
+  echo "Usage: star.sh file outdir"
+  exit
+fi
+
+f="$1"
+outdir="$2"
+
+mkdir -p "$outdir" 2>/dev/null
+
+getData() {
+  dd if="$f" bs=1 skip=$1 count=$2 2>/dev/null
+}
+
+getLong() {
+  getData $1 8 | od -A n -t u8 | tr -d " "
+}
+
+magic=$(getData 0 15)
+if [ "$magic" != "SINGLE_N_LONELY" ]; then
+  echo " Unsupported"; exit 1
+fi
+
+seekoff=256
+for i in $(seq 64); do
+  name="$(getData $seekoff 248)"
+  [ "$name" = "LONELY_N_SINGLE" ] && break
+  length="$(getLong $((seekoff+248)))"
+  offset="$((seekoff+256))"
+  pad=$((length%4096))
+  [ "$pad" -ne 0 ] && pad=$((4096-pad))
+  echo "Name: $name, Offset: $offset, Size: $length, Padding: $pad"
+
+  dd if="$f" of="$outdir/$name" iflag=skip_bytes,count_bytes status=none bs=4096 skip=$offset count=$length
+  seekoff="$((offset+length+pad))"
+done