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1.1 ! root 1: .\" Copyright (c) 1987 Regents of the University of California. ! 2: .\" All rights reserved. ! 3: .\" ! 4: .\" This code is derived from software contributed to Berkeley by ! 5: .\" Symmetric Computer Systems. ! 6: .\" ! 7: .\" Redistribution and use in source and binary forms are permitted provided ! 8: .\" that: (1) source distributions retain this entire copyright notice and ! 9: .\" comment, and (2) distributions including binaries display the following ! 10: .\" acknowledgement: ``This product includes software developed by the ! 11: .\" University of California, Berkeley and its contributors'' in the ! 12: .\" documentation or other materials provided with the distribution and in ! 13: .\" all advertising materials mentioning features or use of this software. ! 14: .\" Neither the name of the University nor the names of its contributors may ! 15: .\" be used to endorse or promote products derived from this software without ! 16: .\" specific prior written permission. ! 17: .\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED ! 18: .\" WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF ! 19: .\" MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. ! 20: .\" ! 21: .\" @(#)disklabel.5.5 6.5 (Berkeley) 6/23/90 ! 22: .\" ! 23: .TH DISKLABEL 5 "June 23, 1990" ! 24: .UC 7 ! 25: .SH NAME ! 26: disklabel \- disk pack label ! 27: .SH SYNOPSIS ! 28: .B #include <sys/disklabel.h> ! 29: .SH DESCRIPTION ! 30: Each disk or disk pack on a system may contain a disk label ! 31: which provides detailed information ! 32: about the geometry of the disk and the partitions into which the disk ! 33: is divided. ! 34: It should be initialized when the disk is formatted, ! 35: and may be changed later with the ! 36: .IR disklabel (8) ! 37: program. ! 38: This information is used by the system disk driver and by the bootstrap ! 39: program to determine how to program the drive ! 40: and where to find the filesystems on the disk partitions. ! 41: Additional information is used by the filesystem in order ! 42: to use the disk most efficiently and to locate important filesystem information. ! 43: The description of each partition contains an identifier for the partition ! 44: type (standard filesystem, swap area, etc.). ! 45: The filesystem updates the in-core copy of the label if it contains ! 46: incomplete information about the filesystem. ! 47: .PP ! 48: The label is located in sector number ! 49: .I LABELSECTOR ! 50: of the drive, usually sector 0 where it may be found ! 51: without any information about the disk geometry. ! 52: It is at an offset ! 53: .I LABELOFFSET ! 54: from the beginning of the sector, to allow room for the initial bootstrap. ! 55: The disk sector containing the label is normally made read-only ! 56: so that it is not accidentally overwritten by pack-to-pack copies ! 57: or swap operations; ! 58: the DIOCWLABEL ! 59: .IR ioctl , ! 60: which is done as needed by the ! 61: .IR disklabel (8) ! 62: program. ! 63: .PP ! 64: A copy of the in-core label for a disk can be obtained with the DIOCGDINFO ! 65: .IR ioctl ; ! 66: this works with a file descriptor for a block or character (``raw'') device ! 67: for any partition of the disk. ! 68: The in-core copy of the label is set by the DIOCSDINFO ! 69: .IR ioctl . ! 70: The offset of a partition cannot generally be changed while it is open, ! 71: nor can it be made smaller while it is open. ! 72: One exception is that any change is allowed if no label was found ! 73: on the disk, and the driver was able to construct only a skeletal label ! 74: without partition information. ! 75: Finally, the DIOCWDINFO ! 76: .I ioctl ! 77: operation sets the in-core label and then updates the on-disk label; ! 78: there must be an existing label on the disk for this operation to succeed. ! 79: Thus, the initial label for a disk or disk pack must be installed ! 80: by writing to the raw disk. ! 81: All of these operations are normally done using ! 82: .IR disklabel (8). ! 83: .PP ! 84: The format of the disk label, as specified in ! 85: .RI < sys/disklabel.h >, ! 86: is ! 87: .nf ! 88: .DT ! 89: /* ! 90: * Disk description table, see disktab(5) ! 91: */ ! 92: #define DISKTAB "/etc/disktab" ! 93: ! 94: /* ! 95: * Each disk has a label which includes information about the hardware ! 96: * disk geometry, filesystem partitions, and drive specific information. ! 97: * The label is in block 0 or 1, possibly offset from the beginning ! 98: * to leave room for a bootstrap, etc. ! 99: */ ! 100: .ta \w'#define 'u +\w'MAXPARTITIONS 'u +\w'((u_long) 0x82564557) 'u ! 101: #define LABELSECTOR 0 /* sector containing label */ ! 102: #define LABELOFFSET 64 /* offset of label in sector */ ! 103: #define DISKMAGIC ((u_long) 0x82564557) /* The disk magic number */ ! 104: #ifndef MAXPARTITIONS ! 105: #define MAXPARTITIONS 8 ! 106: #endif ! 107: ! 108: ! 109: .ta \w'struct 'u +\w'u_long 'u +\w'd_packname[16] 'u ! 110: #ifndef LOCORE ! 111: struct disklabel { ! 112: u_long d_magic; /* the magic number */ ! 113: short d_type; /* drive type */ ! 114: short d_subtype; /* controller/d_type specific */ ! 115: char d_typename[16]; /* type name, e.g. "eagle" */ ! 116: /* ! 117: * d_packname contains the pack identifier and is returned when ! 118: * the disklabel is read off the disk or in-core copy. ! 119: * d_boot0 and d_boot1 are the (optional) names of the ! 120: * primary (block 0) and secondary (block 1-15) bootstraps ! 121: * as found in /usr/mdec. These are returned when using ! 122: * getdiskbyname(3) to retrieve the values from /etc/disktab. ! 123: */ ! 124: #if defined(KERNEL) || defined(STANDALONE) ! 125: char d_packname[16]; /* pack identifier */ ! 126: #else ! 127: .ta \w'struct 'u +\w'struct 'u +\w'struct { 'u +\w'un_d_packname[16] 'u ! 128: union { ! 129: char un_d_packname[16]; /* pack identifier */ ! 130: struct { ! 131: char *un_d_boot0; /* primary bootstrap name */ ! 132: char *un_d_boot1; /* secondary bootstrap name */ ! 133: } un_b; ! 134: } d_un; ! 135: .ta \w'#define 'u +\w'd_packname 'u ! 136: #define d_packname d_un.un_d_packname ! 137: #define d_boot0 d_un.un_b.un_d_boot0 ! 138: #define d_boot1 d_un.un_b.un_d_boot1 ! 139: #endif /* ! KERNEL or STANDALONE */ ! 140: .ta \w'struct 'u +\w'u_short 'u +\w'd_d_drivedata[NDDATA] 'u ! 141: /* disk geometry: */ ! 142: u_long d_secsize; /* # of bytes per sector */ ! 143: u_long d_nsectors; /* # of data sectors per track */ ! 144: u_long d_ntracks; /* # of tracks per cylinder */ ! 145: u_long d_ncylinders; /* # of data cylinders per unit */ ! 146: u_long d_secpercyl; /* # of data sectors per cylinder */ ! 147: u_long d_secperunit; /* # of data sectors per unit */ ! 148: /* ! 149: * Spares (bad sector replacements) below ! 150: * are not counted in d_nsectors or d_secpercyl. ! 151: * Spare sectors are assumed to be physical sectors ! 152: * which occupy space at the end of each track and/or cylinder. ! 153: */ ! 154: u_short d_sparespertrack; /* # of spare sectors per track */ ! 155: u_short d_sparespercyl; /* # of spare sectors per cylinder */ ! 156: /* ! 157: * Alternate cylinders include maintenance, replacement, ! 158: * configuration description areas, etc. ! 159: */ ! 160: u_long d_acylinders; /* # of alt. cylinders per unit */ ! 161: ! 162: /* hardware characteristics: */ ! 163: /* ! 164: * d_interleave, d_trackskew and d_cylskew describe perturbations ! 165: * in the media format used to compensate for a slow controller. ! 166: * Interleave is physical sector interleave, set up by the formatter ! 167: * or controller when formatting. When interleaving is in use, ! 168: * logically adjacent sectors are not physically contiguous, ! 169: * but instead are separated by some number of sectors. ! 170: * It is specified as the ratio of physical sectors traversed ! 171: * per logical sector. Thus an interleave of 1:1 implies contiguous ! 172: * layout, while 2:1 implies that logical sector 0 is separated ! 173: * by one sector from logical sector 1. ! 174: * d_trackskew is the offset of sector 0 on track N ! 175: * relative to sector 0 on track N-1 on the same cylinder. ! 176: * Finally, d_cylskew is the offset of sector 0 on cylinder N ! 177: * relative to sector 0 on cylinder N-1. ! 178: */ ! 179: u_short d_rpm; /* rotational speed */ ! 180: u_short d_interleave; /* hardware sector interleave */ ! 181: u_short d_trackskew; /* sector 0 skew, per track */ ! 182: u_short d_cylskew; /* sector 0 skew, per cylinder */ ! 183: u_long d_headswitch; /* head switch time, usec */ ! 184: u_long d_trkseek; /* track-to-track seek, usec */ ! 185: u_long d_flags; /* generic flags */ ! 186: #define NDDATA 5 ! 187: u_long d_drivedata[NDDATA]; /* drive-type specific information */ ! 188: #define NSPARE 5 ! 189: u_long d_spare[NSPARE]; /* reserved for future use */ ! 190: u_long d_magic2; /* the magic number (again) */ ! 191: u_short d_checksum; /* xor of data incl. partitions */ ! 192: ! 193: /* filesystem and partition information: */ ! 194: u_short d_npartitions; /* number of partitions in following */ ! 195: u_long d_bbsize; /* size of boot area at sn0, bytes */ ! 196: u_long d_sbsize; /* max size of fs superblock, bytes */ ! 197: struct partition { /* the partition table */ ! 198: .ta \w'struct 'u +\w'struct 'u +\w'u_short 'u +\w'd_d_drivedata[NDDATA] 'u ! 199: u_long p_size; /* number of sectors in partition */ ! 200: u_long p_offset; /* starting sector */ ! 201: u_long p_fsize; /* filesystem basic fragment size */ ! 202: u_char p_fstype; /* filesystem type, see below */ ! 203: u_char p_frag; /* filesystem fragments per block */ ! 204: u_short p_cpg; /* filesystem cylinders per group */ ! 205: .ta \w'struct 'u +\w'u_short 'u +\w'd_d_drivedata[NDDATA] 'u ! 206: } d_partitions[MAXPARTITIONS]; /* actually may be more */ ! 207: }; ! 208: ! 209: /* d_type values: */ ! 210: .ta \w'#define 'u +\w'DTYPE_FLOPPY 'u +\w'0x10 'u ! 211: #define DTYPE_SMD 1 /* SMD, XSMD; VAX hp/up */ ! 212: #define DTYPE_MSCP 2 /* MSCP */ ! 213: #define DTYPE_DEC 3 /* other DEC (rk, rl) */ ! 214: #define DTYPE_SCSI 4 /* SCSI */ ! 215: #define DTYPE_ESDI 5 /* ESDI interface */ ! 216: #define DTYPE_ST506 6 /* ST506 etc. */ ! 217: #define DTYPE_FLOPPY 10 /* floppy */ ! 218: ! 219: #ifdef DKTYPENAMES ! 220: static char *dktypenames[] = { ! 221: "unknown", ! 222: "SMD", ! 223: "MSCP", ! 224: "old DEC", ! 225: "SCSI", ! 226: "ESDI", ! 227: "type 6", ! 228: "type 7", ! 229: "type 8", ! 230: "type 9", ! 231: "floppy", ! 232: 0 ! 233: }; ! 234: #define DKMAXTYPES (sizeof(dktypenames) / sizeof(dktypenames[0]) - 1) ! 235: #endif ! 236: ! 237: /* ! 238: * Filesystem type and version. ! 239: * Used to interpret other filesystem-specific ! 240: * per-partition information. ! 241: */ ! 242: #define FS_UNUSED 0 /* unused */ ! 243: #define FS_SWAP 1 /* swap */ ! 244: #define FS_V6 2 /* Sixth Edition */ ! 245: #define FS_V7 3 /* Seventh Edition */ ! 246: #define FS_SYSV 4 /* System V */ ! 247: #define FS_V71K 5 /* V7 with 1K blocks (4.1, 2.9) */ ! 248: #define FS_V8 6 /* Eighth Edition, 4K blocks */ ! 249: #define FS_BSDFFS 7 /* 4.2BSD fast file system */ ! 250: ! 251: #ifdef DKTYPENAMES ! 252: static char *fstypenames[] = { ! 253: "unused", ! 254: "swap", ! 255: "Version 6", ! 256: "Version 7", ! 257: "System V", ! 258: "4.1BSD", ! 259: "Eighth Edition", ! 260: "4.2BSD", ! 261: 0 ! 262: }; ! 263: #define FSMAXTYPES (sizeof(fstypenames) / sizeof(fstypenames[0]) - 1) ! 264: #endif ! 265: ! 266: /* ! 267: * flags shared by various drives: ! 268: */ ! 269: #define D_REMOVABLE 0x01 /* removable media */ ! 270: #define D_ECC 0x02 /* supports ECC */ ! 271: #define D_BADSECT 0x04 /* supports bad sector forw. */ ! 272: #define D_RAMDISK 0x08 /* disk emulator */ ! 273: #define D_CHAIN 0x10 /* can do back-back transfers */ ! 274: ! 275: /* ! 276: * Drive data for SMD. ! 277: */ ! 278: .ta \w'#define 'u +\w'DTYPE_FLOPPY 'u +\w'd_drivedata[1] 'u ! 279: #define d_smdflags d_drivedata[0] ! 280: #define D_SSE 0x1 /* supports skip sectoring */ ! 281: #define d_mindist d_drivedata[1] ! 282: #define d_maxdist d_drivedata[2] ! 283: #define d_sdist d_drivedata[3] ! 284: ! 285: /* ! 286: * Drive data for ST506. ! 287: */ ! 288: #define d_precompcyl d_drivedata[0] ! 289: #define d_gap3 d_drivedata[1] /* used only when formatting */ ! 290: ! 291: #ifndef LOCORE ! 292: /* ! 293: * Structure used to perform a format ! 294: * or other raw operation, returning data ! 295: * and/or register values. ! 296: * Register identification and format ! 297: * are device- and driver-dependent. ! 298: */ ! 299: .ta \w'struct 'u +\w'daddr_t 'u +\w'df_startblk 'u ! 300: struct format_op { ! 301: char *df_buf; ! 302: int df_count; /* value-result */ ! 303: daddr_t df_startblk; ! 304: int df_reg[8]; /* result */ ! 305: }; ! 306: ! 307: /* ! 308: * Structure used internally to retrieve ! 309: * information about a partition on a disk. ! 310: */ ! 311: struct partinfo { ! 312: struct disklabel *disklab; ! 313: struct partition *part; ! 314: }; ! 315: ! 316: /* ! 317: * Disk-specific ioctls. ! 318: */ ! 319: /* get and set disklabel; DIOCGPART used internally */ ! 320: .ta \w'#define 'u +\w'DIOCSRETRIES 'u +\w'_IOW( d , 103, struct disklabel) 'u ! 321: #define DIOCGDINFO _IOR('d', 101, struct disklabel) /* get */ ! 322: #define DIOCSDINFO _IOW('d', 102, struct disklabel) /* set */ ! 323: #define DIOCWDINFO _IOW('d', 103, struct disklabel) /* set, update disk */ ! 324: #define DIOCGPART _IOW('d', 104, struct partinfo) /* get partition */ ! 325: ! 326: /* do format operation, read or write */ ! 327: #define DIOCRFORMAT _IOWR('d', 105, struct format_op) ! 328: #define DIOCWFORMAT _IOWR('d', 106, struct format_op) ! 329: ! 330: #define DIOCSSTEP _IOW('d', 107, int) /* set step rate */ ! 331: #define DIOCSRETRIES _IOW('d', 108, int) /* set # of retries */ ! 332: #define DIOCWLABEL _IOW('d', 109, int) /* write en/disable label */ ! 333: ! 334: #define DIOCSBAD _IOW('d', 110, struct dkbad) /* set kernel dkbad */ ! 335: ! 336: #endif LOCORE ! 337: .SH "SEE ALSO" ! 338: disktab(5), disklabel(8)
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