DKSD(4spp)          RISC/os Reference Manual           DKSD(4spp)



NAME
     dksd - sable disk emulation device

SYNOPSIS
     {
          "dksd",        sdinit,  sdopen,
          sdstrategy,   nulldev, sdioctl,
          DTTYPEBLOCK,
          DTFSAUTO,     "sable disk"
     }

DESCRIPTION
     Dksd is the interface to the sable disk emulation.  Sable
     responds to block requests on the dksd device by transfer-
     ring blocks from the file RootDev in the directory where
     sable was run.  Dksd supports a single controller and unit.
     Partitions on the dksd device are defined by the disk volume
     header in the file RootDev.  Raw transfers to the dksd dev-
     ice must be in multiples of 512 bytes.

REGISTERS
     Sable supports a single disk emulation "controller" with
     control registers at 0x1f001000 in physical space.

IOCTLS
     Dksd supports the following ioctls:

   ioctl(fd, DIOCGETVH, vhp)
     Gets the disk volume header for the dksd device open on fd
     and copies it to the struct volumeheader pointed to by vhp.

   ioctl(fd, DIOCSETVH, vhp)
     Sets the volume header information used by the dksd driver
     to that pointed to by vhp.  DIOCSETVH only changes the
     information used by the disk driver software, it does NOT
     change the information on the disk itself.

   ioctl(fd, DIOCGETCTLR, cip)
     Gets the controller information for the device associated
     with descriptor fd and copies it to the struct ctlrinfo
     pointed to by cip.

DIAGNOSTICS
     The following diagnostics are printed by the dksd driver:

     sd bad unit
          A unit number other than 0 was specified

     sd bad controller number
          A controller number other than 0 was specified

     no sable controller at 0x%x



                         Printed 1/6/92                    Page 1

DKSD(4spp)          RISC/os Reference Manual           DKSD(4spp)



          Sable did not respond to references to the control
          registers at the address shown

     can't read volume header
          A volume header was not present on RootDev or was
          incorrectly formatted or a volume header checksum error
          was detected

     sd bad partition
          A partition number outside the range of 0 to 15 was
          specified

     sd null partition
          A partition was selected that was not found.

     read beyond end of partition
          A read or write was attempted to a disk block beyond
          the end of the partition

     sable disk error
          Sable was unable to read the requested block from Root-
          Dev

SEE ALSO
     dvh(5spp)






























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