1.\" Copyright (c) 1996 2.\" Mike Pritchard <mpp@FreeBSD.org>. All rights reserved. 3.\" 4.\" Copyright (c) 1983, 1991, 1993 5.\" The Regents of the University of California. 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.\" 3. All advertising materials mentioning features or use of this software 16.\" must display the following acknowledgement: 17.\" This product includes software developed by the University of 18.\" California, Berkeley and its contributors. 19.\" 4. Neither the name of the University nor the names of its contributors 20.\" may be used to endorse or promote products derived from this software 21.\" without specific prior written permission. 22.\" 23.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33.\" SUCH DAMAGE. 34.\" 35.\" @(#)mtio.4 8.1 (Berkeley) 6/5/93 36.\" $Id$ 37.\" 38.Dd February 11, 1996 39.Dt MTIO 4 i386 40.Os FreeBSD 2.2 41.Sh NAME 42.Nm mtio 43.Nd 44.Tn FreeBSD 45magtape interface 46.Sh DESCRIPTION 47The special files 48named 49.Pa /dev/[nr]st* 50refer to SCSI tape drives, 51which may be attached to the system. 52.Pa /dev/[nr]st*.ctl 53are control devices that can be used to issue ioctls to the SCSI 54tape driver to set parameters that are required to last beyond the 55unmounting of a tape. 56.Pp 57.Pp 58The rewind devices automatically rewind 59when the last requested read, write or seek has finished, or the end of the tape 60has been reached. The letter 61.Ql n 62is usually prepended to 63the name of the no-rewind devices. 64.Pp 65Tapes can be written with either fixed length records or variable length 66records. See 67.Xr st 4 68for more information. Two end-of-file markers mark the end of a tape, and 69one end-of-file marker marks the end of a tape file. 70If the tape is not to be rewound it is positioned with the 71head in between the two tape marks, where the next write 72will over write the second end-of-file marker. 73.Pp 74All of the magtape devices may be manipulated with the 75.Xr mt 1 76command. 77.Pp 78A number of 79.Xr ioctl 2 80operations are available 81on raw magnetic tape. 82The following definitions are from 83.Aq Pa sys/mtio.h : 84.Bd -literal 85/* 86 * Structures and definitions for mag tape io control commands 87 */ 88 89/* structure for MTIOCTOP - mag tape op command */ 90struct mtop { 91 short mt_op; /* operations defined below */ 92 daddr_t mt_count; /* how many of them */ 93}; 94 95/* operations */ 96#define MTWEOF 0 /* write an end-of-file record */ 97#define MTFSF 1 /* forward space file */ 98#define MTBSF 2 /* backward space file */ 99#define MTFSR 3 /* forward space record */ 100#define MTBSR 4 /* backward space record */ 101#define MTREW 5 /* rewind */ 102#define MTOFFL 6 /* rewind and put the drive offline */ 103#define MTNOP 7 /* no operation, sets status only */ 104#define MTCACHE 8 /* enable controller cache */ 105#define MTNOCACHE 9 /* disable controller cache */ 106 107#if defined(__FreeBSD__) 108/* Set block size for device. If device is a variable size dev */ 109/* a non zero parameter will change the device to a fixed block size */ 110/* device with block size set to that of the parameter passed in. */ 111/* Resetting the block size to 0 will restore the device to a variable */ 112/* block size device. */ 113 114#define MTSETBSIZ 10 115 116/* Set density values for device. They are defined in the SCSI II spec */ 117/* and range from 0 to 0x17. Sets the value for the opened mode only */ 118 119#define MTSETDNSTY 11 120 121#define MTERASE 12 /* erase to EOM */ 122#define MTEOD 13 /* Space to EOM */ 123#define MTCOMP 14 /* select compression mode 0=off, 1=def */ 124#define MTRETENS 15 /* re-tension tape */ 125 126#endif 127 128/* structure for MTIOCGET - mag tape get status command */ 129 130struct mtget { 131 short mt_type; /* type of magtape device */ 132/* the following two registers are grossly device dependent */ 133 short mt_dsreg; /* ``drive status'' register */ 134 short mt_erreg; /* ``error'' register */ 135/* end device-dependent registers */ 136 short mt_resid; /* residual count */ 137#if defined (__FreeBSD__) 138 daddr_t mt_blksiz; /* presently operating blocksize */ 139 daddr_t mt_density; /* presently operating density */ 140 daddr_t mt_comp; /* presently operating compression */ 141 daddr_t mt_blksiz0; /* blocksize for mode 0 */ 142 daddr_t mt_blksiz1; /* blocksize for mode 1 */ 143 daddr_t mt_blksiz2; /* blocksize for mode 2 */ 144 daddr_t mt_blksiz3; /* blocksize for mode 3 */ 145 daddr_t mt_density0; /* density for mode 0 */ 146 daddr_t mt_density1; /* density for mode 1 */ 147 daddr_t mt_density2; /* density for mode 2 */ 148 daddr_t mt_density3; /* density for mode 3 */ 149/* the following are not yet implemented */ 150 u_char mt_comp0; /* compression type for mode 0 */ 151 u_char mt_comp1; /* compression type for mode 1 */ 152 u_char mt_comp2; /* compression type for mode 2 */ 153 u_char mt_comp3; /* compression type for mode 3 */ 154#endif 155 daddr_t mt_fileno; /* file number of current position */ 156 daddr_t mt_blkno; /* block number of current position */ 157/* end not yet implemented */ 158}; 159 160/* 161 * Constants for mt_type byte. These are the same 162 * for controllers compatible with the types listed. 163 */ 164#define MT_ISTS 0x01 /* TS-11 */ 165#define MT_ISHT 0x02 /* TM03 Massbus: TE16, TU45, TU77 */ 166#define MT_ISTM 0x03 /* TM11/TE10 Unibus */ 167#define MT_ISMT 0x04 /* TM78/TU78 Massbus */ 168#define MT_ISUT 0x05 /* SI TU-45 emulation on Unibus */ 169#define MT_ISCPC 0x06 /* SUN */ 170#define MT_ISAR 0x07 /* SUN */ 171#define MT_ISTMSCP 0x08 /* DEC TMSCP protocol (TU81, TK50) */ 172#define MT_ISCY 0x09 /* CCI Cipher */ 173#define MT_ISCT 0x0a /* HP 1/4 tape */ 174#define MT_ISFHP 0x0b /* HP 7980 1/2 tape */ 175#define MT_ISEXABYTE 0x0c /* Exabyte */ 176#define MT_ISEXA8200 0x0c /* Exabyte EXB-8200 */ 177#define MT_ISEXA8500 0x0d /* Exabyte EXB-8500 */ 178#define MT_ISVIPER1 0x0e /* Archive Viper-150 */ 179#define MT_ISPYTHON 0x0f /* Archive Python (DAT) */ 180#define MT_ISHPDAT 0x10 /* HP 35450A DAT drive */ 181#define MT_ISMFOUR 0x11 /* M4 Data 1/2 9track drive */ 182#define MT_ISTK50 0x12 /* DEC SCSI TK50 */ 183#define MT_ISMT02 0x13 /* Emulex MT02 SCSI tape controller */ 184 185/* mag tape io control commands */ 186#define MTIOCTOP _IOW('m', 1, struct mtop) /* do a mag tape op */ 187#define MTIOCGET _IOR('m', 2, struct mtget) /* get tape status */ 188#define MTIOCIEOT _IO('m', 3) /* ignore EOT error */ 189#define MTIOCEEOT _IO('m', 4) /* enable EOT error */ 190 191#ifndef KERNEL 192#define DEFTAPE "/dev/nrst0" 193#endif 194 195#ifdef KERNEL 196/* 197 * minor device number 198 */ 199 200#define T_UNIT 003 /* unit selection */ 201#define T_NOREWIND 004 /* no rewind on close */ 202#define T_DENSEL 030 /* density select */ 203#define T_800BPI 000 /* select 800 bpi */ 204#define T_1600BPI 010 /* select 1600 bpi */ 205#define T_6250BPI 020 /* select 6250 bpi */ 206#define T_BADBPI 030 /* undefined selection */ 207#endif 208#endif /* _SYS_MTIO_H_ */ 209.Ed 210.Pp 211.Sh FILES 212.Bl -tag -width /dev/[nr]st* -compact 213.It Pa /dev/[nr]st* 214.El 215.Sh SEE ALSO 216.Xr mt 1 , 217.Xr tar 1 , 218.Xr st 4 219.Sh HISTORY 220The 221.Nm mtio 222manual appeared in 223.Bx 4.2 . 224An i386 version first appeared in 225.Fx 2.2 . 226.Sh BUGS 227The status should be returned in a device independent format. 228.Pp 229The special file naming should be redone in a more consistent and 230understandable manner. 231