DISKPART(5)             COMMAND REFERENCE             DISKPART(5)



NAME
     diskpart - results of IDSKIOCIDDRV rigid disk ioctl

SYNOPSIS
     #include <sys/ioctl.h>
     #include <machine/idiskioctl.h>

     ioctl(fd, IDSKIOCIDDRV, argp)
     int fd;
     struct  id_drvstat *argp;

DESCRIPTION
     The IDDRV command is used to obtain information about a
     rigid disk partition (this does not apply to floppy disks).
     The file descripter must be opened on any raw device
     associated with the disk of interest.  For example,
     information about partition 2 (normally swap space) on the
     internal disk of a 4310 would be obtained by opening
     /dev/rdw00[a-p] and calling ioctl with the IDSKIOCIDDRV
     command.

     The structure id_drvstat can be found in the include file
     <machine/idiskioctl.h> and is shown below:

          /*
           * Copyright (C) 1983, Tektronix Inc. - All rights Reserved
           *
           */

          /*
           * struct id_drvstat - status of a drive -- the result of an
           *  IDDRV command. These structures should match those defined
           *  in the maintenance block structure.
           */

          #define IDPARTCNT       16              /* partitions/drive */
          struct  id_volume_id {
                  char    idvi_disk_id[8];        /* 8 bytes of ID */
                  char    idvi_diskname[8];       /* disk type name */
          };
          struct  id_phys_desc {
                  unsigned short  idpy_ncyl;      /* nbr of cylinders */
                  unsigned char   idpy_nhead;     /* number of heads */
                  unsigned char   idpy_nsect;     /* USED sectors/track */
                  unsigned char   idpy_nspare;    /* SPARE sectors/track */
                  unsigned char   idpy_bps;       /* coded data sector size */
                  unsigned short  idpy_rpm;       /* rotational speed */
          };
          struct id_partinfo {
                  unsigned short  idpi_ncyls;     /* size (in cylinders) */
                  unsigned short  idpi_cylofst;   /* starting cylinder number */
                  char            idpi_type[2];   /* 2 char type (e.g. "US") */



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DISKPART(5)             COMMAND REFERENCE             DISKPART(5)



                  char            idpi_val[2];    /* 2 byte type-specific data */
          };
          #define idpi_blksiz     idpi_val[0]     /* coded fs blksize for "UF" */
          #define idpi_frgsiz     idpi_val[1]     /* coded fs fragsize for "UF" */

          struct id_drvstat {
                  struct id_volume_id idds_vid;
                  struct id_phys_desc idds_phys;
                  struct id_partinfo  idds_part[IDPARTCNT];
          };

          /*
           * values for id_phys_desc.idpy_bps
           */

          #define IDMB_BPS_128    0
          #define IDMB_BPS_256    1
          #define IDMB_BPS_512    2
          #define IDMB_BPS_1024   3

          /*
           * values for id_partinfo.idpi_blksiz and id_partinfo.idpi_frgsiz
           * powers of 2, representing upper and lower limits
           */

          #define IDMB_BLKL       ((char)12)
          #define IDMB_BLKH       ((char)13)
          #define IDMB_FRGL       ((char)9)
          #define IDMB_FRGH       ((char)12)

          /*
           * convert encoded value of id_partinfo.idpi_blksiz to integer
           */

          #define idmb_blktosiz(code)     (1 << (int)(code))

          /*
           * convert encoded value of id_partinfo.idpi_frgsiz to integer
           */

          #define idmb_frgtosiz(code)     (1 << (int)(code))

     The following is a summary of the possible values of
     idpi_type:

          UF UTek file system partition.

          US UTek paging space.

          XX Unused partition.

          RW Read/Write, a misnomer, used exclusively for the data space partition.



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DISKPART(5)             COMMAND REFERENCE             DISKPART(5)



          DG Diagnostic partition.

          MP Maintenance partition.

          WD Whole disk partition.

EXAMPLES
     This example program estimates how many page pairs can be
     held by the standard swap space on a 4310.

          #define    stratos
          #include <stdio.h>
          #include <sys/ioctl.h>
          #include <machine/idiskioctl.h>

          #define PAIRSIZE        1024

          static  struct  id_drvstat      info_buffer;

          main()
          {
                  register int    fd;
                  register struct id_drvstat *argp;
                  register int    bytes;

                  argp = &info_buffer;
                  fd = open("/dev/rdw00b", 0);
                  ioctl(fd, IDSKIOCIDDRV, argp);
                  if (strncmp(argp->idds_part[1].idpi_type, "US", 2)
                          != 0) {
                          fprintf(stderr, "failed consistency test.");
                          exit(1);
                  }
                  switch (argp->idds_phys.idpy_bps) {
                  case IDMB_BPS_128:   bytes = 128;   break;
                  case IDMB_BPS_256:   bytes = 256;   break;
                  case IDMB_BPS_512:   bytes = 512;   break;
                  case IDMB_BPS_1024:  bytes = 1024;  break;
                  }
                  bytes *= argp->idds_phys.idpy_nsect;
                  bytes *= argp->idds_phys.idpy_nhead;
                  bytes *= argp->idds_part[1].idpi_ncyls;
                  printf("swap space will hold %d page pairs\n",
                          bytes / PAIRSIZE);
          }

SEE ALSO
     ioctl(2), dh(4), and dw(4).







Printed 3/13/89                                                 3

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