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CFUMASS(4)	       FreeBSD Kernel Interfaces Manual		    CFUMASS(4)

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:

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

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

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

     o	 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 auto-
     mated 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.

FreeBSD	13.0			April 21, 2018			  FreeBSD 13.0

NAME | SYNOPSIS | DESCRIPTION | SYSCTL VARIABLES | SEE ALSO | HISTORY | AUTHORS

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=cfumass&sektion=4&manpath=FreeBSD+12.1-RELEASE+and+Ports>

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