xref: /freebsd/share/man/man4/cfumass.4 (revision f8b865d1d62d17626ab993212963277c06cc25b8)
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4.\" This software was developed by Edward Tomasz Napierala under sponsorship
5.\" from the FreeBSD Foundation.
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28.\" $FreeBSD$
29.Dd April 9, 2018
30.Dt CFUMASS 4
31.Os
32.Sh NAME
33.Nm cfumass
34.Nd USB device side support for Mass Storage Class Transport
35.Sh SYNOPSIS
36This driver can be compiled into the kernel by placing these lines in
37the kernel configuration file:
38.Bd -ragged -offset indent
39.Cd "device usb"
40.Cd "device usb_template"
41.Cd "device ctl"
42.Cd "device cfumass"
43.Ed
44.Pp
45The driver module can also be loaded at boot by adding this line to
46.Xr loader.conf 5 :
47.Bd -literal -offset indent
48cfumass_load="YES"
49.Ed
50.Sh DESCRIPTION
51The
52.Nm
53driver provides device side support for emulating an USB mass storage
54device compliant with the USB Mass Storage Class Bulk-Only (BBB) Transport
55specification, implemented as a
56.Xr ctl 4
57frontend driver.
58.Pp
59To use
60.Nm :
61.Bl -bullet
62.It
63.Xr cfumass 4
64must be loaded as a module or compiled into the kernel.
65.It
66The USB Mass Storage template must be chosen by setting the
67.Va hw.usb.template
68sysctl to 0.
69.It
70The USB OTG port must be working in USB device-side mode.
71This happens automatically upon connection to a USB host.
72.It
73There must be a
74.Xr ctl 4
75LUN configured for the
76.Pa cfumass
77port.
78.El
79.Pp
80Upon loading, the driver creates a
81.Xr ctl 4
82port named
83.Pa cfumass ,
84presenting the first LUN mapped for that port - usually LUN 0 - to
85the USB host.
86See
87.Xr ctl.conf 5
88and
89.Xr ctld 8
90for details on configuring the LUN.
91.Sh SYSCTL VARIABLES
92These variables are available as both
93.Xr sysctl 8
94variables and
95.Xr loader 8
96tunables:
97.Bl -tag -width indent
98.It Va hw.usb.cfumass.debug
99Verbosity level for log messages from the
100.Nm
101driver.
102Set to 0 to disable logging or 1 to warn about potential problems.
103Larger values enable debugging output.
104Defaults to 1.
105.It Va hw.usb.cfumass.ignore_stop
106Ignore START STOP UNIT SCSI commands with START and LOEJ bits cleared.
107Some initiators send that command to stop the target when the user
108attempts to gracefully eject the drive, but fail to start it when the
109drive is reconnected.
110Set to 0 to handle the command in a standards-compliant way,
1111 to ignore it and log a warning, or 2 to ignore it silently.
112Defaults to 1.
113.It Va hw.usb.cfumass.max_lun
114Max LUN number to report to the initiator (USB host).
115Must be between 0 and 15.
116Some initiators incorrectly handle values larger than 0.
117Defaults to 0.
118.El
119.Sh SEE ALSO
120.Xr ctl 4 ,
121.Xr umass 4 ,
122.Xr usb 4 ,
123.Xr usb_template 4 ,
124.Xr ctl.conf 5 ,
125.Xr ctld 8
126.Sh HISTORY
127The
128.Nm
129driver first appeared in
130.Fx 11.1 .
131.Sh AUTHORS
132The
133.Nm
134driver was developed by
135.An Edward Tomasz Napierala Aq Mt trasz@FreeBSD.org
136under sponsorship from the FreeBSD Foundation.
137