NAME

       cfumass — USB device side support for Mass Storage Class Transport

SYNOPSIS

       This driver can be compiled into the kernel by placing these lines in the kernel configuration file:

             device usb
             device usb_template
             device ctl
             device cfumass

       The driver module can also be loaded at boot by adding this line to loader.conf(5):

             cfumass_load="YES"

DESCRIPTION

       The  cfumass  driver provides device side support for emulating an USB mass storage device compliant with
       the USB Mass Storage Class Bulk-Only (BBB) Transport specification,  implemented  as  a  ctl(4)  frontend
       driver.

       To use cfumass:

       •   cfumass(4) must be loaded as a module or compiled into the kernel.

       •   The USB Mass Storage template must be chosen by setting the hw.usb.template sysctl to 0.

       •   The USB OTG port must be working in USB device-side mode.  This happens automatically upon connection
           to a USB host.

       •   There must be a ctl(4) LUN configured for the cfumass port.

       Upon  loading,  the  driver creates a ctl(4) port named cfumass, presenting the first LUN mapped for that
       port - usually LUN 0 - to the USB host.  See ctl.conf(5) and ctld(8) for details on configuring the  LUN.
       See the cfumass_enable and cfumass_dir rc(8) variables in rc.conf(5) for an automated way to configure it
       at boot.

SYSCTL VARIABLES

       These variables are available as both sysctl(8) variables and loader(8) tunables:

       hw.usb.cfumass.debug
               Verbosity  level  for  log messages from the cfumass driver.  Set to 0 to disable logging or 1 to
               warn about potential problems.  Larger values enable debugging output.  Defaults to 1.

       hw.usb.cfumass.ignore_stop
               Ignore START STOP UNIT SCSI commands with START and LOEJ bits cleared.  Some initiators send that
               command to stop the target when the user attempts to gracefully eject  the  drive,  but  fail  to
               start  it when the drive is reconnected.  Set to 0 to handle the command in a standards-compliant
               way, 1 to ignore it and log a warning, or 2 to ignore it silently.  Defaults to 1.

       hw.usb.cfumass.max_lun
               Max LUN number to report to the initiator (USB host).  Must be between 0 and 15.  Some initiators
               incorrectly handle values larger than 0.  Defaults to 0.

SEE ALSO

       ctl(4), umass(4), usb(4), usb_template(4), ctl.conf(5), ctld(8)

HISTORY

       The cfumass driver first appeared in FreeBSD 11.1.

AUTHORS

       The cfumass driver was developed by Edward Tomasz Napierala <trasz@FreeBSD.org>  under  sponsorship  from
       the FreeBSD Foundation.

Debian                                           April 21, 2018                                       CFUMASS(4)