fs command

Synopsis

fs mount [<dev> <mountpoint>]                   - list or create mounts
fs mount <iface> <dev:part> <mountpoint>        - auto-detect and mount
fs mount -t <type> <iface> <dev:part> <mountpoint> - mount specific type
fs umount <mountpoint> | -a                     - unmount a filesystem
fs ls [<path>]                                  - list directory (default /)
fs cp <source> <dest>                           - copy a file

Description

The fs command provides access to the virtual filesystem (VFS) layer. It allows filesystems to be mounted at paths within a unified namespace, then listed and navigated using absolute paths.

On first use the VFS is automatically initialised with an empty root filesystem at /.

See Virtual Filesystem (VFS) for more information about the VFS layer.

fs mount

Without arguments, lists all current mounts showing the mount point and the name of the UCLASS_FS device mounted there.

With two arguments, mounts the filesystem device dev at mountpoint. The device is looked up by name in UCLASS_FS.

With three arguments (iface dev:part mountpoint), auto-detects the filesystem type on the block device and mounts it. Each registered VFS filesystem type is tried in turn.

With -t, specifies the filesystem type explicitly.

dev: Name of a UCLASS_FS device (e.g. hostfs for the sandbox host filesystem)
mountpoint: Absolute path where the filesystem should be mounted (must start with /)

fs umount

Unmounts the filesystem at mountpoint and removes the corresponding UCLASS_MOUNT device.

mountpoint: Path of an existing mount point

fs ls

Lists the contents of a directory. If no path is given, lists the root directory /.

At the root level, mount points appear as directories. Within a mounted filesystem, actual directory entries are shown along with any child mount points.

path: Absolute path to list (default /)

fs cp

Copies a file from source to dest. Both paths can be on different mounted filesystems, enabling cross-filesystem copies. The file is copied in chunks.

source: Absolute or relative path to the source file
dest: Absolute or relative path to the destination file (created if it does not exist)

Example

=> fs mount hostfs /host
=> fs mount
/host                hostfs
=> fs ls /
DIR          0 host
=> fs ls /host
DIR       4096 arch
DIR      12288 cmd
   ...
=> fs umount /host

Auto-detect a filesystem on a block device:

=> host bind 0 /tmp/ext4.img
=> fs mount host 0:0 /mnt
=> fs ls /mnt
DIR      16384 lost+found
=> fs umount /mnt

Configuration

The fs command is available when CONFIG_CMD_VFS=y, which depends on CONFIG_VFS=y.

Return value

The return value $? is set to 0 (true) if the command succeeded, 1 (false) otherwise.