Add -o <outfile> to mkplatformfs.sh for feature parity

mkplatformfs.sh.in

@@ -61,6 +61,7 @@ Options
     -C <file>   Full path to the XBPS configuration file
     -r <repo>   Set XBPS repository (may be set multiple times)
     -x <num>    Use <num> threads to compress the image (dynamic if unset)
+    -o <file>   Filename to write the PLATFORMFS archive to
     -n          Do not compress the image, instead print out the rootfs directory
     -h          Show this help
     -V          Show version
@@ -74,7 +75,7 @@ _EOF
 BASEPKG=base-system
 COMPRESSION="y"
 
-while getopts "b:p:k:c:C:r:x:nhV" opt; do
+while getopts "b:p:k:c:C:r:x:o:nhV" opt; do
     case $opt in
         b) BASEPKG="$OPTARG" ;;
         p) EXTRA_PKGS="$OPTARG" ;;
@@ -83,6 +84,7 @@ while getopts "b:p:k:c:C:r:x:nhV" opt; do
         C) XBPS_CONFFILE="-C $OPTARG" ;;
         r) XBPS_REPOSITORY="$XBPS_REPOSITORY --repository=$OPTARG" ;;
         x) COMPRESSOR_THREADS="$OPTARG" ;;
+        o) FILENAME="$OPTARG" ;;
         n) COMPRESSION="n" ;;
         h) usage; exit 0 ;;
         V) echo "$PROGNAME @@MKLIVE_VERSION@@"; exit 0 ;;
@@ -222,7 +224,7 @@ fi
 if [ "$COMPRESSION" = "y" ]; then
     # Finally we can compress the tarball, the name will include the
     # platform and the date on which the tarball was built.
-    tarball=void-${PLATFORM}-PLATFORMFS-$(date '+%Y%m%d').tar.xz
+    tarball=${FILENAME:-void-${PLATFORM}-PLATFORMFS-$(date '+%Y%m%d').tar.xz}
     run_cmd "tar -cp --posix --xattrs -C $ROOTFS . | xz -T${COMPRESSOR_THREADS:-0} -9 > $tarball "
 
     # Now that we have the tarball we don't need the rootfs anymore, so we