scripts/ext-tools: introduce new script to install prebuilt tools

Add a simple script to make it easier to install a prebuilt tools tar.
Currently it will be used by our tools container and kernel workflow on
github.

Simple script that take a tar that contains prebuilt host tools, extract
them and refresh the timestamps to skip recompilation of such host
tools.

By default it refresh timestamps of build_dir/host and
staging_dir/host/stamp.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>

scripts/ext-tools.sh

@@ -0,0 +1,98 @@
+#!/usr/bin/env bash
+
+TOOLS_TAR=""
+HOST_BUILD_DIR=$(pwd)/"build_dir/host"
+HOST_STAGING_DIR_STAMP=$(pwd)/"staging_dir/host/stamp"
+
+refresh_timestamps() {
+	find "$1" -not -type l -print0 | xargs -0 touch
+}
+
+extract_prebuilt_tar() {
+	tar -xf "$1"
+}
+
+install_prebuilt_tools() {
+	extract_prebuilt_tar "$TOOLS_TAR"
+
+	if [ ! -d "$HOST_BUILD_DIR" ]; then
+		echo "Can't find Host Build Dir "$HOST_BUILD_DIR"" >&2
+		exit 1
+	fi
+
+	refresh_timestamps "$HOST_BUILD_DIR"
+	sleep 1
+
+	if [ ! -d "$HOST_STAGING_DIR_STAMP" ]; then
+		echo "Can't find Host Staging Dir Stamp "$HOST_STAGING_DIR_STAMP"" >&2
+		exit 1
+	fi
+
+	refresh_timestamps "$HOST_STAGING_DIR_STAMP"
+
+	return 0
+}
+
+while [ -n "$1" ]; do
+	arg="$1"; shift
+	case "$arg" in
+		--host-build-dir)
+			[ -d "$1" ] || {
+				echo "Directory '$1' does not exist." >&2
+				exit 1
+			}
+			HOST_BUILD_DIR="$(cd "$1"; pwd)"; shift
+		;;
+
+		--host-staging-dir-stamp)
+			[ -d "$1" ] || {
+				echo "Directory '$1' does not exist." >&2
+				exit 1
+			}
+			HOST_STAGING_DIR_STAMP="$(cd "$1"; pwd)"; shift
+		;;
+
+		--tools)
+			[ -f "$1" ] || {
+				echo "Tools tar file '$1' does not exist." >&2
+				exit 1
+			}
+			TOOLS_TAR="$1"; shift
+			install_prebuilt_tools
+
+			exit $?
+		;;
+
+		-h|--help)
+			me="$(basename "$0")"
+			echo -e "\nUsage:\n"                                            >&2
+			echo -e "  $me --host-build-dir {directory}"                    >&2
+			echo -e "    Set to refresh timestamp of this build directory"  >&2
+			echo -e "    with --tools."                                     >&2
+			echo -e "    THIS OPTION MUST BE SET BEFORE --tools."           >&2
+			echo -e "    If not provided the default directory is:"         >&2
+			echo -e "    $(pwd)/build_dir/host\n"                           >&2
+			echo -e "  $me --host-staging-dir-stamp {directory}"            >&2
+			echo -e "    Set to refresh staging timestamp present in this"  >&2
+			echo -e "    directory with --tools."                           >&2
+			echo -e "    THIS OPTION MUST BE SET BEFORE --tools."           >&2
+			echo -e "    If not provided the default directory is:"         >&2
+			echo -e "    $(pwd)/staging_dir/host/stamp\n"                   >&2
+			echo -e "  $me --tools {tar}"                                   >&2
+			echo -e "    Install the prebuilt tools present in the passed"  >&2
+			echo -e "    tar and prepare them."                             >&2
+			echo -e "    To correctly use them it's needed to update the."  >&2
+			echo -e "    timestamp of each tools to skip recompilation.\n"  >&2
+			echo -e "  $me --help"                                          >&2
+			echo -e "    Display this help text and exit.\n\n"              >&2
+			exit 1
+		;;
+
+		*)
+			echo "Unknown argument '$arg'" >&2
+			exec $0 --help
+		;;
+	esac
+done
+
+exec $0 --help