include/dvh.h

   1 /*
   2  * Copyright (c) 2000 Silicon Graphics, Inc.  All Rights Reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of version 2 of the GNU General Public License as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it would be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  11  *
  12  * Further, this software is distributed without any warranty that it is
  13  * free of the rightful claim of any third person regarding infringement
  14  * or the like.  Any license provided herein, whether implied or
  15  * otherwise, applies only to this software file.  Patent licenses, if
  16  * any, provided herein do not apply to combinations of this program with
  17  * other software, or any other product whatsoever.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write the Free Software Foundation, Inc., 59
  21  * Temple Place - Suite 330, Boston MA 02111-1307, USA.
  22  *
  23  * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
  24  * Mountain View, CA  94043, or:
  25  *
  26  * http://www.sgi.com
  27  *
  28  * For further information regarding this notice, see:
  29  *
  30  * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
  31  */
  32 #ifndef __DVH_H__
  33 #define __DVH_H__
  34
  35 /*
  36  * Format for volume header information
  37  *
  38  * The volume header is a block located at the beginning of all disk
  39  * media (sector 0).  It contains information pertaining to physical
  40  * device parameters and logical partition information.
  41  *
  42  * The volume header is manipulated by disk formatters/verifiers,
  43  * partition builders (e.g. fx, dvhtool, and mkfs), and disk drivers.
  44  *
  45  * Previous versions of IRIX wrote a copy of the volume header is
  46  * located at sector 0 of each track of cylinder 0.  These copies were
  47  * never used, and reduced the capacity of the volume header to hold large
  48  * files, so this practice was discontinued.
  49  * The volume header is constrained to be less than or equal to 512
  50  * bytes long.  A particular copy is assumed valid if no drive errors
  51  * are detected, the magic number is correct, and the 32 bit 2's complement
  52  * of the volume header is correct.  The checksum is calculated by initially
  53  * zeroing vh_csum, summing the entire structure and then storing the
  54  * 2's complement of the sum.  Thus a checksum to verify the volume header
  55  * should be 0.
  56  *
  57  * The error summary table, bad sector replacement table, and boot blocks are
  58  * located by searching the volume directory within the volume header.
  59  *
  60  * Tables are sized simply by the integral number of table records that
  61  * will fit in the space indicated by the directory entry.
  62  *
  63  * The amount of space allocated to the volume header, replacement blocks,
  64  * and other tables is user defined when the device is formatted.
  65  */
  66
  67 /*
  68  * device parameters are in the volume header to determine mapping
  69  * from logical block numbers to physical device addresses
  70  *
  71  * Linux doesn't care ...
  72  */
  73 struct device_parameters {
  74         unsigned char   dp_skew;        /* spiral addressing skew */
  75         unsigned char   dp_gap1;        /* words of 0 before header */
  76         unsigned char   dp_gap2;        /* words of 0 between hdr and data */
  77         unsigned char   dp_spares_cyl;  /* This is for drives (such as SCSI
  78                 that support zone oriented sparing, where the zone is larger
  79                 than one track.  It gets subracteded from the cylinder size
  80                 ( dp_trks0 * dp_sec) when doing partition size calculations */
  81         unsigned short  dp_cyls;        /* number of usable cylinders (i.e.,
  82                 doesn't include cylinders reserved by the drive for badblocks,
  83                 etc.). For drives with variable geometry, this number may be
  84                 decreased so that:
  85                 dp_cyls * ((dp_heads * dp_trks0) - dp_spares_cyl) <= actualcapacity
  86                 This happens on SCSI drives such as the Wren IV and Toshiba 156
  87                 Also see dp_cylshi below */
  88         unsigned short  dp_shd0;        /* starting head vol 0 */
  89         unsigned short  dp_trks0;       /* number of tracks / cylinder vol 0*/
  90         unsigned char   dp_ctq_depth;   /* Depth of CTQ queue */
  91         unsigned char   dp_cylshi;      /* high byte of 24 bits of cylinder count */
  92         unsigned short  dp_unused;      /* not used */
  93         unsigned short  dp_secs;        /* number of sectors/track */
  94         unsigned short  dp_secbytes;    /* length of sector in bytes */
  95         unsigned short  dp_interleave;  /* sector interleave */
  96         int     dp_flags;               /* controller characteristics */
  97         int     dp_datarate;            /* bytes/sec for kernel stats */
  98         int     dp_nretries;            /* max num retries on data error */
  99         int     dp_mspw;                /* ms per word to xfer, for iostat */
 100         unsigned short dp_xgap1;        /* Gap 1 for xylogics controllers */
 101         unsigned short dp_xsync;    /* sync delay for xylogics controllers */
 102         unsigned short dp_xrdly;    /* read delay for xylogics controllers */
 103         unsigned short dp_xgap2;    /* gap 2 for xylogics controllers */
 104         unsigned short dp_xrgate;   /* read gate for xylogics controllers */
 105         unsigned short dp_xwcont;   /* write continuation for xylogics */
 106 };
 107
 108 /*
 109  * Device characterization flags
 110  * (dp_flags)
 111  */
 112 #define DP_SECTSLIP     0x00000001      /* sector slip to spare sector */
 113 #define DP_SECTFWD      0x00000002      /* forward to replacement sector */
 114 #define DP_TRKFWD       0x00000004      /* forward to replacement track */
 115 #define DP_MULTIVOL     0x00000008      /* multiple volumes per spindle */
 116 #define DP_IGNOREERRORS 0x00000010      /* transfer data regardless of errors */
 117 #define DP_RESEEK       0x00000020      /* recalibrate as last resort */
 118 #define DP_CTQ_EN       0x00000040      /* enable command tag queueing */
 119
 120 /*
 121  * Boot blocks, bad sector tables, and the error summary table, are located
 122  * via the volume_directory.
 123  */
 124 #define VDNAMESIZE      8
 125
 126 struct volume_directory {
 127         char    vd_name[VDNAMESIZE];    /* name */
 128         int     vd_lbn;                 /* logical block number */
 129         int     vd_nbytes;              /* file length in bytes */
 130 };
 131
 132 /*
 133  * partition table describes logical device partitions
 134  * (device drivers examine this to determine mapping from logical units
 135  * to cylinder groups, device formatters/verifiers examine this to determine
 136  * location of replacement tracks/sectors, etc)
 137  *
 138  * NOTE: pt_firstlbn SHOULD BE CYLINDER ALIGNED
 139  */
 140 struct partition_table {                /* one per logical partition */
 141         int     pt_nblks;               /* # of logical blks in partition */
 142         int     pt_firstlbn;            /* first lbn of partition */
 143         int     pt_type;                /* use of partition */
 144 };
 145
 146 #define PTYPE_VOLHDR    0               /* partition is volume header */
 147 #define PTYPE_TRKREPL   1               /* partition is used for repl trks */
 148 #define PTYPE_SECREPL   2               /* partition is used for repl secs */
 149 #define PTYPE_RAW       3               /* partition is used for data */
 150 #define PTYPE_BSD42     4               /* partition is 4.2BSD file system */
 151 #define PTYPE_BSD       4               /* partition is 4.2BSD file system */
 152 #define PTYPE_SYSV      5               /* partition is SysV file system */
 153 #define PTYPE_VOLUME    6               /* partition is entire volume */
 154 #define PTYPE_EFS       7               /* partition is sgi EFS */
 155 #define PTYPE_LVOL      8               /* partition is part of a logical vol */
 156 #define PTYPE_RLVOL     9               /* part of a "raw" logical vol */
 157 #define PTYPE_XFS       10              /* partition is sgi XFS */
 158 #define PTYPE_XFSLOG    11              /* partition is sgi XFS log */
 159 #define PTYPE_XLV       12              /* partition is part of an XLV vol */
 160 #define PTYPE_XVM       13              /* partition is sgi XVM */
 161 #define NPTYPES         16
 162
 163 #define VHMAGIC         0xbe5a941       /* randomly chosen value */
 164 #define NPARTAB         16              /* 16 unix partitions */
 165 #define NVDIR           15              /* max of 15 directory entries */
 166 #define BFNAMESIZE      16              /* max 16 chars in boot file name */
 167
 168 /* Partition types for ARCS */
 169 #define NOT_USED        0       /* Not used                             */
 170 #define FAT_SHORT       1       /* FAT filesystem, 12-bit FAT entries   */
 171 #define FAT_LONG        4       /* FAT filesystem, 16-bit FAT entries   */
 172 #define EXTENDED        5       /* extended partition                   */
 173 #define HUGE            6       /* huge partition- MS/DOS 4.0 and later */
 174
 175 /* Active flags for ARCS */
 176 #define BOOTABLE        0x00;
 177 #define NOT_BOOTABLE    0x80;
 178
 179 struct volume_header {
 180         int vh_magic;                           /* identifies volume header */
 181         short vh_rootpt;                        /* root partition number */
 182         short vh_swappt;                        /* swap partition number */
 183         char vh_bootfile[BFNAMESIZE];           /* name of file to boot */
 184         struct device_parameters vh_dp;         /* device parameters */
 185         struct volume_directory vh_vd[NVDIR];   /* other vol hdr contents */
 186         struct partition_table vh_pt[NPARTAB];  /* device partition layout */
 187         int vh_csum;                            /* volume header checksum */
 188         int vh_fill;    /* fill out to 512 bytes */
 189 };
 190
 191 #endif  /* __DVH_H__ */