+/**
+ * Read the sandbox state from the supplied device tree file
+ *
+ * This calls all registered state handlers to read in the sandbox state
+ * from a previous test run.
+ *
+ * @param state Sandbox state to update
+ * @param fname Filename of device tree file to read from
+ * @return 0 if OK, -ve on error
+ */
+int sandbox_read_state(struct sandbox_state *state, const char *fname);
+
+/**
+ * Write the sandbox state to the supplied device tree file
+ *
+ * This calls all registered state handlers to write out the sandbox state
+ * so that it can be preserved for a future test run.
+ *
+ * If the file exists it is overwritten.
+ *
+ * @param state Sandbox state to update
+ * @param fname Filename of device tree file to write to
+ * @return 0 if OK, -ve on error
+ */
+int sandbox_write_state(struct sandbox_state *state, const char *fname);
+
+/**
+ * Add a property to a sandbox state node
+ *
+ * This is equivalent to fdt_setprop except that it automatically enlarges
+ * the device tree if necessary. That means it is safe to write any amount
+ * of data here.
+ *
+ * This function can only be called from within struct sandbox_state_io's
+ * ->write method, i.e. within state I/O drivers.
+ *
+ * @param node Device tree node to write to
+ * @param prop_name Property to write
+ * @param data Data to write into property
+ * @param size Size of data to write into property
+ */
+int state_setprop(int node, const char *prop_name, const void *data, int size);
+
+/**
+ * Control skipping of time delays
+ *
+ * Some tests have unnecessay time delays (e.g. USB). Allow these to be
+ * skipped to speed up testing
+ *
+ * @param skip_delays true to skip delays from now on, false to honour delay
+ * requests
+ */
+void state_set_skip_delays(bool skip_delays);
+
+/**
+ * See if delays should be skipped
+ *
+ * @return true if delays should be skipped, false if they should be honoured
+ */
+bool state_get_skip_delays(void);
+