Provided by: sg3-utils_1.17-2_i386
sg_get_config - invoke SCSI GET CONFIGURATION command on a (cd/dvd)
sg_get_config [--brief] [--current] [--help] [--hex] [--inner-hex]
[--list] [--rt=<n>] [--starting=<n>] [--verbose] [--version] <device>
Sends a SCSI GET CONFIGURATION command to the given Linux device and
decodes the response. The response includes the features and profiles
of the device. Typically these devices are CD and DVD players that may
(but not necessarily) have media in them. These devices may well be
connected via ATAPI, USB or IEEE 1394 transports. In such cases they
are "SCSI" devices only in the sense that they use the "Multi-Media
command" set (MMC). MMC is a specialized SCSI command set whose
definition can be found at http://www.t10.org .
This utility is based on the MMC-4 and MMC-5 draft standards. See
section 5 on "Features and Profile for Multi_Media devices" for more
information on specific feature parameters and profiles. The
manufacturer’s product manual may also be useful.
Since modern DVD writers support many features and profiles, the
decoded output from this utility can be large. There are various ways
to cut down the output. If the ’--brief’ option is used only the
feature names are shown and the feature parameters are not decoded.
Alternatively if only one feature is of interest then this combination
of options is appropriate: "--rt=2 --starting=<feature_code>". Another
possibility is to show only the features that are relevant to the media
in the drive (i.e. "current") with the "--rt=1" option.
--brief | -b
show the feature names but don’t decode the parameters of those
features. When used with ’--list’ outputs known feature names
but not known profile names.
--current | -c
output features marked as current. This option is equivalent to
--help | -h
output the usage message then exit.
--hex | -H
output the response in hex (don’t decode response).
--inner-hex | -i
decode to the feature name level then output each feature’s data
--list | -l
list all known feature and profile names. Ignore the device name
(if given). Simply lists the feature names and profiles
(followed by their hex values) that this utility knows about. If
’--brief’ is also given then only feature names are listed.
--rt=<n> | -r <n>
RT value given to GET CONFIGURATION command. Allowable values
are 0, 1, 2, or 3 . The command’s action also depends on the
value given to ’--starting=’. The default value is 0. When <n>
is 0 then all features, regardless of currency, are returned
(whose feature code is greater than or equal to the value given
to ’--starting=’). When <n> is 1 then all current features are
returned (whose feature code is greater than or equal to the
value given to ’--starting=’). When <n> is 2 then the feature
whose feature code is equal to the value given to ’--starting=’,
if any, is returned. When <n> is 3 the response is reserved
(probably yields an "illegal field in cdb" error).
--starting=<n> | -s <n>
this option works closely with the --rt option. Its value is a
feature code in the range 0 to 0xffff (inclusive). Its default
value is 0. A value prefixed with "0x" is interpreted as
--verbose | -v
increase the level of verbosity, (i.e. debug output).
--version | -V
print the version string and then exit.
There are multiple versions of the MMC (draft) standards: MMC ,
MMC-2 , MMC-3 , MMC-4 and MMC-5. The first three are now
ANSI INCITS standards with the year they became standards shown in
brackets. The draft immediately prior to standardization can be found
at http://www.t10.org . In the initial MMC standard there was no GET
CONFIGURATION command and the relevant information was obtained from
the "CD capabilities and mechanical status mode page" (mode page 0x2a).
It was later renamed the "MM capabilities and mechanical status mode
page" and has been made obsolete in MMC-4 and MMC-5. The GET
CONFIGURATION command was introduced in MMC-2 and has become a
replacement for that mode page. New features such as support for "BD"
(blue ray) media type can only be found by using the GET CONFIGURATION
command. Hence older CD players may not support the GET CONFIGURATION
command in which case the "MM capabilities ..." mode page can be
checked with sdpar, sginfo or sg_modes.
In the 2.4 series of Linux kernels the given device must be a SCSI
generic (sg) device. In the 2.6 series block devices can also be
specified. For example "sg_get_config /dev/hdc" will work in the 2.6
series kernels as long as /dev/hdc is an ATAPI device. In the 2.6
series external DVD writers attached via USB could be queried with
"sg_get_config /dev/scd1" for example.
Written by Douglas Gilbert.
Report bugs to <dgilbert at interlog dot com>.
Copyright © 2004-2005 Douglas Gilbert
This software is distributed under a FreeBSD license. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR
sginfo, sg_modes, sg_inq, sg_prevent, sg_start (all in sg3_utils)