1.\" 2.\" SPDX-License-Identifier: BSD-2-Clause 3.\" 4.\" Copyright (c) 1999 5.\" Nick Hibma <n_hibma@FreeBSD.org>. All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.Dd October 9, 2025 29.Dt UMASS 4 30.Os 31.Sh NAME 32.Nm umass 33.Nd USB Mass Storage Devices driver 34.Sh SYNOPSIS 35.Cd "device da" 36.Cd "device scbus" 37.Cd "device pass" 38.Cd "device usb" 39.Cd "device umass" 40.Pp 41In 42.Xr loader.conf 5 : 43.Cd umass_load 44.Sh DESCRIPTION 45The 46.Nm 47driver provides support for Mass Storage devices that attach to the USB 48interface. 49.Pp 50If the appropriate hardware is detected, 51the driver will be loaded automatically by 52.Xr devmatch 8 . 53To load the driver manually at boot time, use the 54.Cm umass_load 55command at the 56.Xr loader 8 57prompt, or add it to 58.Xr loader.conf 5 . 59.Pp 60To use the driver in a custom kernel, 61.Xr usb 4 62and at least one of 63.Xr uhci 4 , 64.Xr ohci 4 , 65.Xr ehci 4 , 66or 67.Xr xhci 4 68must be configured in the kernel. 69Additionally, since 70.Nm 71uses the SCSI subsystem and sometimes acts as a SCSI device, it 72requires 73.Xr da 4 74and 75.Xr scbus 4 76to be included in the kernel. 77.Sh HARDWARE 78The 79.Nm 80driver supports USB Mass Storage devices such as: 81.Pp 82.Bl -bullet -compact 83.It 84USB thumb drives 85.It 86USB hard disk drives 87.It 88USB floppy drives 89.El 90.Sh EXAMPLES 91Rescan all slots on a multi-slot flash reader, 92where the slots map to separate LUNs on a single SCSI ID: 93.Bd -literal -offset indent 94camcontrol rescan 0:0:0 95camcontrol rescan 0:0:1 96camcontrol rescan 0:0:2 97camcontrol rescan 0:0:3 98.Ed 99.Pp 100Typically only the first slot will be enabled at boot time. 101This assumes that 102the flash reader is the first SCSI bus in the system and has 4 slots. 103.Sh SEE ALSO 104.Xr cfumass 4 , 105.Xr ehci 4 , 106.Xr ohci 4 , 107.Xr uhci 4 , 108.Xr usb 4 , 109.Xr xhci 4 , 110.Xr camcontrol 8 111.Sh HISTORY 112The 113.Nm 114driver appeared in 115.Fx 4.3 . 116.Sh AUTHORS 117.An -nosplit 118The 119.Nm 120driver was written by 121.An MAEKAWA Masahide Aq Mt bishop@rr.iij4u.or.jp 122and 123.An Nick Hibma Aq Mt n_hibma@FreeBSD.org . 124.Pp 125This manual page was written by 126.An Nick Hibma Aq Mt n_hibma@FreeBSD.org . 127