mufs: mufs_mount() read the tree pointer of the root directory

include/fs/mufs.h

@@ -2,10 +2,15 @@
 
 struct flash_dev;
 
+struct mufs_tree {
+	uint32_t root;
+	uint8_t depth;
+};
+
 struct mufs {
 	struct flash_dev *dev;
 	uint32_t nblocks;
-	uint32_t root;
+	struct mufs_tree root;
 };
 
 int mufs_mount(struct mufs *fs, struct flash_dev *dev);

source/fs/mufs/super.c

@@ -10,6 +10,7 @@ struct mufs_super {
 	char magic[4];
 	uint32_t nblocks;
 	uint32_t root;
+	uint8_t depth;
 } __attribute__((packed));
 
 int mufs_mount(struct mufs *fs, struct flash_dev *dev)
@@ -27,7 +28,8 @@ int mufs_mount(struct mufs *fs, struct flash_dev *dev)
 
 	fs->dev = dev;
 	fs->nblocks = super.nblocks;
-	fs->root = super.root;
+	fs->root.root = super.root;
+	fs->root.depth = super.depth;
 
 	return 0;
 }
@@ -39,6 +41,7 @@ int mufs_format(struct flash_dev *dev)
 	memcpy(super.magic, "mufs", 4);
 	super.nblocks = flash_get_capacity(dev) >> dev->log2_block_size;
 	super.root = 0;
+	super.depth = 0;
 
 	if (flash_write(dev, 0, &super, sizeof super) == 0)
 		return -1;

source/fs/mufs/tree.h

@@ -1,10 +1,5 @@
 #pragma once
 
-struct mufs_tree {
-	uint32_t root;
-	uint8_t depth;
-};
-
 int mufs_lookup_page(struct mufs *fs, struct mufs_tree *tree, uint32_t *page,
 	uint32_t va);
 int mufs_alloc_page(struct mufs *fs, struct mufs_tree *tree, uint32_t *page,