blob: 9d379e3c829ea4c2ed595423afb2827156540582 [file] [log] [blame]
.. SPDX-License-Identifier: GPL-2.0+
.. index::
single: ums (command)
ums command
===========
Synopsis
--------
::
ums <dev> [<interface>] <devnum[:partnum]>
Description
-----------
Use the USB Mass Storage class (also known as UMS) to make accessible an U-Boot
block device (fully or with :ref:`U-Boot's partition syntax <partitions>`)
to a USB host and to enable file transfers. U-Boot, the USB device, acts as a
simple external hard drive plugged on the host USB port.
This command "ums" stays in the USB's treatment loop until user enters Ctrl-C.
dev
USB gadget device number
interface
interface for accessing the block device (mmc, sata, scsi, usb, ....)
defaults is "mmc"
devnum
device number for selected interface
partnum
partition number or 0 to expose all partitions, defaults to 0
Example
-------
::
=> ums 0 mmc 0
=> ums 0 usb 1:2
Configuration
-------------
The ums command is only available if CONFIG_CMD_USB_MASS_STORAGE=y
and depends on CONFIG_USB_USB_GADGET and CONFIG_BLK.
Return value
------------
The return value $? is set to 0 (true) when the USB stack was successfully
started and interrupted, with Ctrl-C or after USB cable issue (detection
timeout or cable removal).
If an error occurs, the return value $? is set to 1 (false).