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"Das U-Boot" Source Tree
1.. SPDX-License-Identifier: GPL-2.0+
2
3.. index::
4 single: ums (command)
5
6ums command
7===========
8
9Synopsis
10--------
11
12::
13
14 ums <dev> [<interface>] <devnum[:partnum]>
15
16Description
17-----------
18
19Use the USB Mass Storage class (also known as UMS) to make accessible an U-Boot
20block device (fully or with :ref:`U-Boot's partition syntax <partitions>`)
21to a USB host and to enable file transfers. U-Boot, the USB device, acts as a
22simple external hard drive plugged on the host USB port.
23
24This command "ums" stays in the USB's treatment loop until user enters Ctrl-C.
25
26dev
27 USB gadget device number
28
29interface
30 interface for accessing the block device (mmc, sata, scsi, usb, ....)
31 defaults is "mmc"
32
33devnum
34 device number for selected interface
35
36partnum
37 partition number or 0 to expose all partitions, defaults to 0
38
39Example
40-------
41
42::
43
44 => ums 0 mmc 0
45 => ums 0 usb 1:2
46
47Configuration
48-------------
49
50The ums command is only available if CONFIG_CMD_USB_MASS_STORAGE=y
51which depends on CONFIG_USB_GADGET_DOWNLOAD and CONFIG_BLK.
52
53Return value
54------------
55
56The return value $? is set to 0 (true) when the USB stack was successfully
57started and interrupted, with Ctrl-C or after USB cable issue (detection
58timeout or cable removal).
59
60If an error occurs, the return value $? is set to 1 (false).