+static int parse_new_root_from_proc_cmdline(void) {
+ char *w, *state;
+ _cleanup_free_ char *what = NULL, *type = NULL, *opts = NULL, *line = NULL;
+ int r;
+ size_t l;
+ bool wait = false;
+
+ r = read_one_line_file("/proc/cmdline", &line);
+ if (r < 0) {
+ log_error("Failed to read /proc/cmdline, ignoring: %s", strerror(-r));
+ return 0;
+ }
+
+ opts = strdup("defaults");
+ if (!opts)
+ return log_oom();
+ type = strdup("auto");
+ if (!type)
+ return log_oom();
+
+ /* root= and roofstype= may occur more than once, the last instance should take precedence.
+ * In the case of multiple rootflags= the arguments should be concatenated */
+ FOREACH_WORD_QUOTED(w, l, line, state) {
+ char *word, *tmp_word;
+
+ word = strndup(w, l);
+ if (!word)
+ return log_oom();
+
+ else if (startswith(word, "root=")) {
+ free(what);
+ what = fstab_node_to_udev_node(word+5);
+ if (!what)
+ return log_oom();
+
+ } else if (startswith(word, "rootfstype=")) {
+ free(type);
+ type = strdup(word + 11);
+ if (!type)
+ return log_oom();
+
+ } else if (startswith(word, "rootflags=")) {
+ tmp_word = opts;
+ opts = strjoin(opts, ",", word + 10, NULL);
+ free(tmp_word);
+ if (!opts)
+ return log_oom();
+
+ } else if (streq(word, "ro") || streq(word, "rw")) {
+ tmp_word = opts;
+ opts = strjoin(opts, ",", word, NULL);
+ free(tmp_word);
+ if (!opts)
+ return log_oom();
+
+ } else if (streq(word, "rootwait"))
+ wait = true;
+
+ free(word);
+ }
+
+ if (what) {
+
+ log_debug("Found entry what=%s where=/new_root type=%s", what, type);
+ r = add_mount(what, "/new_root", type, opts, 0, wait, false, false,
+ false, false, false, "/proc/cmdline");
+
+ if (r < 0)
+ return r;
+ } else
+ log_error("Could not find a root= entry on the kernel commandline.");
+ }
+
+ return 0;
+}
+