discover: Implement device priorities
[petitboot] / discover / device-handler.c
index cdfee483767e449c885d0ebf3db3671040a4c78f..f9d2dbf5d53f1450d56c0c201738567cfb9b9166 100644 (file)
@@ -334,17 +334,50 @@ static int default_timeout(void *arg)
        return 0;
 }
 
-static void set_default(struct device_handler *handler,
+static bool priority_match(struct boot_priority *prio,
                struct discover_boot_option *opt)
 {
-       if (handler->default_boot_option)
-               return;
+       return prio->type == opt->device->device->type;
+}
+
+static int default_option_priority(struct discover_boot_option *opt)
+{
+       const struct config *config;
+       struct boot_priority *prio;
+       int i;
+
+       config = config_get();
+
+       for (i = 0; i < config->n_boot_priorities; i++) {
+               prio = &config->boot_priorities[i];
+               if (priority_match(prio, opt))
+                       break;
+       }
+
+       return i;
+}
 
+static void set_default(struct device_handler *handler,
+               struct discover_boot_option *opt)
+{
        if (!handler->autoboot_enabled)
                return;
 
-       handler->default_boot_option = opt;
+       /* Resolve any conflicts: if we have a new default option, it only
+        * replaces the current if it has a higher priority. */
+       if (handler->default_boot_option) {
+               int new_prio, cur_prio;
+
+               new_prio = default_option_priority(opt);
+               cur_prio = default_option_priority(
+                                       handler->default_boot_option);
+
+               if (new_prio >= cur_prio)
+                       return;
+       }
+
        handler->sec_to_boot = config_get()->autoboot_timeout_sec;
+       handler->default_boot_option = opt;
 
        pb_log("Boot option %s set as default, timeout %u sec.\n",
               opt->option->id, handler->sec_to_boot);