logger params: add SDLOG_MODE to select when to start & stop logging

src/modules/logger/params.c

@@ -48,3 +48,22 @@
  * @group SD Logging
  */
 PARAM_DEFINE_INT32(SDLOG_UTC_OFFSET, 0);
+
+/**
+ * Logging Mode
+ *
+ * Determines when to start and stop logging. By default, logging is started
+ * when arming the system, and stopped when disarming.
+ *
+ * This parameter is only for the new logger (SYS_LOGGER=1).
+ *
+ * @value 0 when armed until disarm (default)
+ * @value 1 from boot until disarm
+ * @value 2 from boot until shutdown
+ *
+ * @min 0
+ * @max 2
+ * @reboot_required true
+ * @group SD Logging
+ */
+PARAM_DEFINE_INT32(SDLOG_MODE, 0);