add a script for unpacking file system images from factory zip files

.editorconfig

@@ -9,3 +9,6 @@ insert_final_newline = true
 
 [*.md]
 trim_trailing_whitespace = false
+
+[*.sh]
+indent_size = 4

scripts/unpack-images.sh

@@ -0,0 +1,70 @@
+#!/usr/bin/env bash
+
+unpack_image() {
+    set -o errexit -o nounset -o pipefail
+
+    ZIP_FILE=$1
+    IMG_FILE=$2
+    echo "$ZIP_FILE/$IMG_FILE"
+
+    unzip $ZIP_FILE $IMG_FILE > /dev/null
+
+    NAME=$(basename $IMG_FILE ".img")
+    MNT="${NAME}_mnt"
+
+    mkdir $MNT
+
+    mount --read-only $IMG_FILE $MNT
+    cp -a $MNT $NAME
+    umount $MNT
+
+    rm --dir $MNT
+    rm $IMG_FILE
+}
+
+export -f unpack_image
+
+unpack_factory_zip() {
+    set -o errexit -o nounset -o pipefail
+
+    cd "$(dirname "$(realpath $1)")"
+    OUTER_ZIP_FILE="$(basename $1)"
+
+    IMAGE_ZIP_PATH=$(zipinfo -l -1 $OUTER_ZIP_FILE "*/image-*")
+    IMAGE_ZIP_DIR_NAME=$(dirname $IMAGE_ZIP_PATH)
+    IMAGE_ZIP_FILE_NAME=$(basename $IMAGE_ZIP_PATH)
+
+    echo "$IMAGE_ZIP_PATH"
+
+    OUT_DIR="unpacked"
+    [[ -d $OUT_DIR ]] || {
+        mkdir $OUT_DIR
+        chown $SUDO_UID:$SUDO_GID $OUT_DIR
+    }
+
+    unzip -d $OUT_DIR $OUTER_ZIP_FILE $IMAGE_ZIP_PATH > /dev/null
+
+    cd "$OUT_DIR/$IMAGE_ZIP_DIR_NAME"
+
+    zipinfo -l -1 $IMAGE_ZIP_FILE_NAME | grep -E '^(system|system_ext|product|vendor|odm).img$|dlkm.img$' | \
+        parallel -u unpack_image $IMAGE_ZIP_FILE_NAME
+
+    rm $IMAGE_ZIP_FILE_NAME
+    chmod -R u+w .
+    chown -R $SUDO_UID:$SUDO_GID .
+}
+
+export -f unpack_factory_zip
+
+[[ -f $1 && $1 =~ .zip$ ]] || {
+    echo "This script extracts and unpacks file system images from factory zip files."
+    echo "Specify one or more factory zip file paths."
+    exit 1
+}
+
+[[ $UID -eq 0 && -n $SUDO_UID && -n $SUDO_GID ]] || {
+    echo "This script needs to be started through sudo to mount file system images and correctly set ownership of unpacked files."
+    exit 1
+}
+
+parallel -u unpack_factory_zip ::: "$@"