move rom tarball creation to script/roms

export LBMK_RELEASE="y"

if this is done, the tarball is created instead
of a directory, and the rom images are nuked using
./vendor inject with the nuke option, inserting the
correct version files; the rom directory is deleted

now the release script logic simple renames existing
tarballs. the benefit of this change is fewer lines of
code, and now lbmk doesn't use an insane amount of disk
space when building a *lot* of release images (the
uncompressed directories are deleted after each build)

Signed-off-by: Leah Rowe <leah@libreboot.org>

include/option.sh

@@ -171,3 +171,41 @@ check_project()
 	done
 	export LOCALVERSION="-${projectname}-${version%%-*}"
 }
+
+mktar_release()
+{
+	x_ insert_version_files "$1"
+	mktarball "$1" "${1}.tar.xz"
+	x_ rm -Rf "$1"
+}
+
+mktarball()
+{
+	# preserve timestamps for reproducible tarballs
+	tar_implementation=$(tar --version | head -n1) || :
+
+	[ "${2%/*}" = "${2}" ] || \
+		mkdir -p "${2%/*}" || $err "mk, !mkdir -p \"${2%/*}\""
+	printf "\nCreating archive: %s\n\n" "$2"
+	if [ "${tar_implementation% *}" = "tar (GNU tar)" ]; then
+		tar --sort=name --owner=root:0 --group=root:0 \
+		    --mtime="UTC 2024-05-04" -c "$1" | xz -T$threads -9e \
+		    > "$2" || $err "mktarball 1, ${1}"
+	else
+		# TODO: reproducible tarballs on non-GNU systems
+		tar -c "$1" | xz -T$threads -9e > "$2" || \
+		    $err "mktarball 2, $1"
+	fi
+	(
+	[ "${2%/*}" != "${2}" ] && x_ cd "${2%/*}"
+	sha512sum "${2##*/}" > "${2##*/}.sha512" || \
+	    $err "!sha512sum \"${2##*/}\" > \"${2##*/}.sha512\""
+	) || $err "failed to create tarball checksum"
+}
+
+insert_version_files()
+{
+	printf "%s\n" "${version}" > "${1}/version" || return 1
+	printf "%s\n" "${versiondate}" > "${1}/versiondate" || return 1
+	printf "%s\n" "${projectname}" > "${1}/projectname" || return 1
+}