fit: If no matching config is found in fit_find_config_node(), use the default one

If board_fit_config_name_match() doesn't match any configuration node,
then use the default one (if provided).
Signed-off-by: NJean-Jacques Hiblot <jjhiblot@ti.com>
Reviewed-by: NTom Rini <trini@konsulko.com>
Reviewed-by: NSimon Glass <sjg@chromium.org>

common/common_fit.c

@@ -32,6 +32,9 @@ int fit_find_config_node(const void *fdt)
 {
 	const char *name;
 	int conf, node, len;
+	const char *dflt_conf_name;
+	const char *dflt_conf_desc = NULL;
+	int dflt_conf_node = -ENOENT;
 
 	conf = fdt_path_offset(fdt, FIT_CONFS_PATH);
 	if (conf < 0) {
@@ -39,6 +42,9 @@ int fit_find_config_node(const void *fdt)
 		      conf);
 		return -EINVAL;
 	}
+
+	dflt_conf_name = fdt_getprop(fdt, conf, "default", &len);
+
 	for (node = fdt_first_subnode(fdt, conf);
 	     node >= 0;
 	     node = fdt_next_subnode(fdt, node)) {
@@ -50,6 +56,15 @@ int fit_find_config_node(const void *fdt)
 #endif
 			return -EINVAL;
 		}
+
+		if (dflt_conf_name) {
+			const char *node_name = fdt_get_name(fdt, node, NULL);
+			if (strcmp(dflt_conf_name, node_name) == 0) {
+				dflt_conf_node = node;
+				dflt_conf_desc = name;
+			}
+		}
+
 		if (board_fit_config_name_match(name))
 			continue;
 
@@ -58,5 +73,10 @@ int fit_find_config_node(const void *fdt)
 		return node;
 	}
 
+	if (dflt_conf_node != -ENOENT) {
+		debug("Selecting default config '%s'", dflt_conf_desc);
+		return dflt_conf_node;
+	}
+
 	return -ENOENT;
 }

include/image.h

@@ -1299,6 +1299,19 @@ void board_fit_image_post_process(void **p_image, size_t *p_size);
 #define FDT_ERROR	((ulong)(-1))
 
 ulong fdt_getprop_u32(const void *fdt, int node, const char *prop);
+
+/**
+ * fit_find_config_node() - Find the node for the best DTB in a FIT image
+ *
+ * A FIT image contains one or more DTBs. This function parses the
+ * configurations described in the FIT images and returns the node of
+ * the first matching DTB. To check if a DTB matches a board, this function
+ * calls board_fit_config_name_match(). If no matching DTB is found, it returns
+ * the node described by the default configuration if it exists.
+ *
+ * @fdt: pointer to flat device tree
+ * @return the node if found, -ve otherwise
+ */
 int fit_find_config_node(const void *fdt);
 
 /**