cmd: mtdparts: use defaults by default

Boards which are defining default mtdparts often need them early
in boot process (to load environment from UBI volume, for example).
This is currently solved by adding mtdparts and mtdids variable
definitions also to default environment. With this change, default
partitions are used by default unless explicitely deleted or
redefined.

Signed-off-by: Ladislav Michl <ladis@linux-mips.org>

cmd/mtdparts.c

@@ -142,6 +142,8 @@ static struct list_head devices;
 struct mtd_device *current_mtd_dev = NULL;
 u8 current_mtd_partnum = 0;
 
+u8 use_defaults;
+
 static struct part_info* mtd_part_info(struct mtd_device *dev, unsigned int part_num);
 
 /* command line only routines */
@@ -1723,6 +1725,7 @@ int mtdparts_init(void)
 		memset(last_ids, 0, MTDIDS_MAXLEN);
 		memset(last_parts, 0, MTDPARTS_MAXLEN);
 		memset(last_partition, 0, PARTITION_MAXLEN);
+		use_defaults = 1;
 		initialized = 1;
 	}
 
@@ -1761,10 +1764,16 @@ int mtdparts_init(void)
 		return 1;
 	}
 
-	/* do no try to use defaults when mtdparts variable is not defined,
-	 * just check the length */
-	if (!parts)
-		printf("mtdparts variable not set, see 'help mtdparts'\n");
+	/* use defaults when mtdparts variable is not defined
+	 * once mtdparts is saved environment, drop use_defaults flag */
+	if (!parts) {
+		if (mtdparts_default && use_defaults) {
+			parts = mtdparts_default;
+			if (setenv("mtdparts", (char *)parts) == 0)
+				use_defaults = 0;
+		} else
+			printf("mtdparts variable not set, see 'help mtdparts'\n");
+	}
 
 	if (parts && (strlen(parts) > MTDPARTS_MAXLEN - 1)) {
 		printf("mtdparts too long (> %d)\n", MTDPARTS_MAXLEN);
@@ -1936,9 +1945,10 @@ static int do_mtdparts(cmd_tbl_t *cmdtp, int flag, int argc,
 {
 	if (argc == 2) {
 		if (strcmp(argv[1], "default") == 0) {
-			setenv("mtdids", (char *)mtdids_default);
-			setenv("mtdparts", (char *)mtdparts_default);
+			setenv("mtdids", NULL);
+			setenv("mtdparts", NULL);
 			setenv("partition", NULL);
+			use_defaults = 1;
 
 			mtdparts_init();
 			return 0;