+#ifdef CONFIG_OF_HOSTFILE
+
+#define CHECK(x) err = (x); if (err) goto failed;
+
+/* Create an empty device tree blob */
+static int make_empty_fdt(void *fdt)
+{
+ int err;
+
+ CHECK(fdt_create(fdt, 256));
+ CHECK(fdt_finish_reservemap(fdt));
+ CHECK(fdt_begin_node(fdt, ""));
+ CHECK(fdt_end_node(fdt));
+ CHECK(fdt_finish(fdt));
+
+ return 0;
+failed:
+ printf("Unable to create empty FDT: %s\n", fdt_strerror(err));
+ return -EACCES;
+}
+
+static int read_fdt_from_file(void)
+{
+ struct sandbox_state *state = state_get_current();
+ void *blob;
+ int size;
+ int err;
+
+ blob = map_sysmem(CONFIG_SYS_FDT_LOAD_ADDR, 0);
+ if (!state->fdt_fname) {
+ err = make_empty_fdt(blob);
+ if (!err)
+ goto done;
+ return err;
+ }
+ err = fs_set_blk_dev("host", NULL, FS_TYPE_SANDBOX);
+ if (err)
+ return err;
+ size = fs_read(state->fdt_fname, CONFIG_SYS_FDT_LOAD_ADDR, 0, 0);
+ if (size < 0)
+ return -EIO;
+
+done:
+ gd->fdt_blob = blob;
+
+ return 0;
+}
+#endif
+