diff --git a/rcore-fs-sefs/src/lib.rs b/rcore-fs-sefs/src/lib.rs
index 7a22479..91c8d27 100644
--- a/rcore-fs-sefs/src/lib.rs
+++ b/rcore-fs-sefs/src/lib.rs
@@ -195,6 +195,7 @@ impl vfs::INode for INodeImpl {
             uid: disk_inode.uid as usize,
             gid: disk_inode.gid as usize,
             blk_size: 0x1000,
+            rdev: 0,
         })
     }
     fn set_metadata(&self, metadata: &vfs::Metadata) -> vfs::Result<()> {
diff --git a/rcore-fs-sfs/src/lib.rs b/rcore-fs-sfs/src/lib.rs
index de16713..2acb580 100644
--- a/rcore-fs-sfs/src/lib.rs
+++ b/rcore-fs-sfs/src/lib.rs
@@ -67,7 +67,7 @@ pub struct INodeImpl {
     fs: Arc<SimpleFileSystem>,
     /// Char/block device id (major, minor)
     /// e.g. crw-rw-rw- 1 root wheel 3, 2 May 13 16:40 /dev/null
-    device_inode_id: usize, 
+    device_inode_id: usize,
 }
 
 impl Debug for INodeImpl {
@@ -470,6 +470,7 @@ impl vfs::INode for INodeImpl {
             uid: 0,
             gid: 0,
             blk_size: BLKSIZE,
+            rdev: self.device_inode_id,
         })
     }
     fn set_metadata(&self, _metadata: &vfs::Metadata) -> vfs::Result<()> {
diff --git a/rcore-fs-sfs/src/tests.rs b/rcore-fs-sfs/src/tests.rs
index cde4174..58235ef 100644
--- a/rcore-fs-sfs/src/tests.rs
+++ b/rcore-fs-sfs/src/tests.rs
@@ -57,6 +57,7 @@ fn create_file() -> Result<()> {
             gid: 0,
             blk_size: 4096,
             dev: 0,
+            rdev: 100, // dummo why 100 here, maybe legacy data?
         }
     );
 
diff --git a/rcore-fs/src/vfs.rs b/rcore-fs/src/vfs.rs
index 4c7f0cb..62c5ef5 100644
--- a/rcore-fs/src/vfs.rs
+++ b/rcore-fs/src/vfs.rs
@@ -160,7 +160,7 @@ pub struct PollStatus {
 #[derive(Debug, Eq, PartialEq)]
 pub struct Metadata {
     /// Device ID
-    pub dev: usize,
+    pub dev: usize, // (major << 8) | minor
     /// Inode number
     pub inode: usize,
     /// Size in bytes
@@ -192,6 +192,9 @@ pub struct Metadata {
     pub uid: usize,
     /// Group ID
     pub gid: usize,
+    /// Raw device id
+    /// e.g. /dev/null: makedev(0x1, 0x3)
+    pub rdev: usize, // (major << 8) | minor
 }
 
 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Debug, Hash)]