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#ifndef _SYS_DVH_H
#define _SYS_DVH_H
/*
* Format for volume header information
*
* The volume header is a block located at the beginning of all disk
* media (sector 0). It contains information pertaining to physical
* device parameters and logical partition information.
*
* The volume header is manipulated by disk formatters/verifiers,
* partition builders (e.g. fx, dvhtool, and mkfs), and disk drivers.
*
* Previous versions of IRIX wrote a copy of the volume header is
* located at sector 0 of each track of cylinder 0. These copies were
* never used, and reduced the capacity of the volume header to hold large
* files, so this practice was discontinued.
* The volume header is constrained to be less than or equal to 512
* bytes long. A particular copy is assumed valid if no drive errors
* are detected, the magic number is correct, and the 32 bit 2's complement
* of the volume header is correct. The checksum is calculated by initially
* zeroing vh_csum, summing the entire structure and then storing the
* 2's complement of the sum. Thus a checksum to verify the volume header
* should be 0.
*
* The error summary table, bad sector replacement table, and boot blocks are
* located by searching the volume directory within the volume header.
*
* Tables are sized simply by the integral number of table records that
* will fit in the space indicated by the directory entry.
*
* The amount of space allocated to the volume header, replacement blocks,
* and other tables is user defined when the device is formatted.
*/
/*
* device parameters are in the volume header to determine mapping
* from logical block numbers to physical device addresses
*
* Linux doesn't care ...
*/
struct device_parameters {
unsigned char dp_skew; /* spiral addressing skew */
unsigned char dp_gap1; /* words of 0 before header */
unsigned char dp_gap2; /* words of 0 between hdr and data */
unsigned char dp_spares_cyl; /* This is for drives (such as SCSI
that support zone oriented sparing, where the zone is larger
than one track. It gets subracteded from the cylinder size
( dp_trks0 * dp_sec) when doing partition size calculations */
unsigned short dp_cyls; /* number of usable cylinders (i.e.,
doesn't include cylinders reserved by the drive for badblocks,
etc.). For drives with variable geometry, this number may be
decreased so that:
dp_cyls * ((dp_heads * dp_trks0) - dp_spares_cyl) <= actualcapacity
This happens on SCSI drives such as the Wren IV and Toshiba 156
Also see dp_cylshi below */
unsigned short dp_shd0; /* starting head vol 0 */
unsigned short dp_trks0; /* number of tracks / cylinder vol 0*/
unsigned char dp_ctq_depth; /* Depth of CTQ queue */
unsigned char dp_cylshi; /* high byte of 24 bits of cylinder count */
unsigned short dp_unused; /* not used */
unsigned short dp_secs; /* number of sectors/track */
unsigned short dp_secbytes; /* length of sector in bytes */
unsigned short dp_interleave; /* sector interleave */
int dp_flags; /* controller characteristics */
int dp_datarate; /* bytes/sec for kernel stats */
int dp_nretries; /* max num retries on data error */
int dp_mspw; /* ms per word to xfer, for iostat */
unsigned short dp_xgap1; /* Gap 1 for xylogics controllers */
unsigned short dp_xsync; /* sync delay for xylogics controllers */
unsigned short dp_xrdly; /* read delay for xylogics controllers */
unsigned short dp_xgap2; /* gap 2 for xylogics controllers */
unsigned short dp_xrgate; /* read gate for xylogics controllers */
unsigned short dp_xwcont; /* write continuation for xylogics */
};
/*
* Device characterization flags
* (dp_flags)
*/
#define DP_SECTSLIP 0x00000001 /* sector slip to spare sector */
#define DP_SECTFWD 0x00000002 /* forward to replacement sector */
#define DP_TRKFWD 0x00000004 /* forward to replacement track */
#define DP_MULTIVOL 0x00000008 /* multiple volumes per spindle */
#define DP_IGNOREERRORS 0x00000010 /* transfer data regardless of errors */
#define DP_RESEEK 0x00000020 /* recalibrate as last resort */
#define DP_CTQ_EN 0x00000040 /* enable command tag queueing */
/*
* Boot blocks, bad sector tables, and the error summary table, are located
* via the volume_directory.
*/
#define VDNAMESIZE 8
struct volume_directory {
char vd_name[VDNAMESIZE]; /* name */
int vd_lbn; /* logical block number */
int vd_nbytes; /* file length in bytes */
};
/*
* partition table describes logical device partitions
* (device drivers examine this to determine mapping from logical units
* to cylinder groups, device formatters/verifiers examine this to determine
* location of replacement tracks/sectors, etc)
*
* NOTE: pt_firstlbn SHOULD BE CYLINDER ALIGNED
*/
struct partition_table { /* one per logical partition */
int pt_nblks; /* # of logical blks in partition */
int pt_firstlbn; /* first lbn of partition */
int pt_type; /* use of partition */
};
#define PTYPE_VOLHDR 0 /* partition is volume header */
#define PTYPE_TRKREPL 1 /* partition is used for repl trks */
#define PTYPE_SECREPL 2 /* partition is used for repl secs */
#define PTYPE_RAW 3 /* partition is used for data */
#define PTYPE_BSD42 4 /* partition is 4.2BSD file system */
#define PTYPE_BSD 4 /* partition is 4.2BSD file system */
#define PTYPE_SYSV 5 /* partition is SysV file system */
#define PTYPE_VOLUME 6 /* partition is entire volume */
#define PTYPE_EFS 7 /* partition is sgi EFS */
#define PTYPE_LVOL 8 /* partition is part of a logical vol */
#define PTYPE_RLVOL 9 /* part of a "raw" logical vol */
#define PTYPE_XFS 10 /* partition is sgi XFS */
#define PTYPE_XFSLOG 11 /* partition is sgi XFS log */
#define PTYPE_XLV 12 /* partition is part of an XLV vol */
#define PTYPE_XVM 13 /* partition is sgi XVM */
#define PTYPE_LSWAP 0x82 /* partition is Linux swap */
#define PTYPE_LINUX 0x83 /* partition is Linux native */
#define NPTYPES 16
#define VHMAGIC 0xbe5a941 /* randomly chosen value */
#define NPARTAB 16 /* 16 unix partitions */
#define NVDIR 15 /* max of 15 directory entries */
#define BFNAMESIZE 16 /* max 16 chars in boot file name */
/* Partition types for ARCS */
#define NOT_USED 0 /* Not used */
#define FAT_SHORT 1 /* FAT filesystem, 12-bit FAT entries */
#define FAT_LONG 4 /* FAT filesystem, 16-bit FAT entries */
#define EXTENDED 5 /* extended partition */
#define HUGE 6 /* huge partition- MS/DOS 4.0 and later */
/* Active flags for ARCS */
#define BOOTABLE 0x00;
#define NOT_BOOTABLE 0x80;
struct volume_header {
int vh_magic; /* identifies volume header */
short vh_rootpt; /* root partition number */
short vh_swappt; /* swap partition number */
char vh_bootfile[BFNAMESIZE]; /* name of file to boot */
struct device_parameters vh_dp; /* device parameters */
struct volume_directory vh_vd[NVDIR]; /* other vol hdr contents */
struct partition_table vh_pt[NPARTAB]; /* device partition layout */
int vh_csum; /* volume header checksum */
int vh_fill; /* fill out to 512 bytes */
};
#endif /* _SYS_DVH_H */
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