fd(7)
NAME
fd, fdc − drivers for floppy disks and floppy disk controllers
CONFIG
x86
name="fd" parent="fdc" unit=0;
name="fd" parent="fdc" unit=1;
DESCRIPTION
The fd driver provides the interfaces to the floppy disks using the Intel 82072 on SUN4c systems and the Intel 82077 on SUN4m systems.
The fd and fdc drivers provide the interfaces to floppy disks using the Intel 8272, Intel 82077, NEC 765, or compatible disk controllers on x86 systems.
The default partitions for the floppy driver are
| a | All cylinders except the last |
| b | Only the last cylinder |
| c | Entire diskette |
The fd driver autosenses the density of the diskette.
When the floppy is first opened the driver looks for a SunOS label in logical block 0 of the diskette. If attempts to read the SunOS label fail, the open will fail. If block 0 is read successfully but a SunOS label is not found, auto-sensed geometry and default partitioning are assumed.
The fd driver supports both block and raw interfaces. The block files access the diskette using the system’s normal buffering mechanism and may be read and written without regard to physical diskette records. There is also a “raw” interface that provides for direct transmission between the diskette and the user’s read or write buffer. A single read(2) or write(2) call usually results in one I/O operation; therefore raw I/O is considerably more efficient when many words are transmitted.
3.5" Diskettes
For 3.5" double-sided diskettes, the following densities are supported:
SPARC
high density
80 cylinders, 18 sectors per track, 1.44 Mbyte capacity
double density
80 cylinders, 9 sectors per track, 720 Kbyte capacity
medium density
77 cylinders, 8 sectors per track, 1.2 Mbyte capacity (SUN4m only)
x86
extended density
80 cylinders, 36 sectors per track, 2.88 Mbyte capacity
high density
80 cylinders, 18 sectors per track, 1.44 Mbyte capacity
double density
80 cylinders, 9 sectors per track, 760 Kbyte capacity
5.25" Diskettes
For 5.25" double-sided diskettes, the following densities are supported:
SPARC
5.25" diskettes are not supported.
x86
high density
80 cylinders, 15 sectors per track, 1.2 Mbyte capacity
double density
40 cylinders, 9 sectors per track, 360 Kbyte capacity
double density
40 cylinders, 8 sectors per track, 320 Kbyte capacity
quad density
80 cylinders, 9 sectors per track, 720 Kbyte capacity
double density
40 cylinders, 16 sectors per track (256 bytes per sector), 320 Kbyte capacity
double density
40 cylinders, 4 sectors per track (1024 bytes per sector), 320 Kbyte capacity
ERRORS
EBUSY During opening, the partition has been opened for exclusive access and another process wants to open the partition. Once open, this error is returned if the floppy disk driver attempted to pass a command to the floppy disk controller when the controller was busy handling another command. In this case, the application should try the operation again.
EFAULT An invalid address was specified in an ioctl command (see fdio(7)).
EINVAL The number of bytes read or written is not a multiple of the diskette’s sector size. This error is also returned when an unsupported command is specified using the FDIOCMD ioctl command (see fdio(7)).
EIO During opening, the diskette does not have a label or there is no diskette in the drive. Once open, this error is returned if the requested I/O transfer could not be completed.
ENOSPC An attempt was made to write past the end of the diskette.
ENOTTY The floppy disk driver does not support the requested ioctl functions (see fdio(7)).
ENXIO The floppy disk device does not exist or the device is not ready.
EROFS The floppy disk device is opened for write access and the diskette in the drive is write protected.
x86 Only
ENOSYS The floppy disk device does not support the requested ioctl function ( FDEJECT).
FILES
SPARC
/kernel/drv/fd driver module
/usr/include/sys/fdreg.h
structs and definitions for Intel 82072 and 82077 controllers
/usr/include/sys/fdvar.h
structs and definitions for floppy drivers
/dev/diskette device file
/dev/diskette0 device file
/dev/rdiskette raw device file
/dev/rdiskette0 raw device file
For ucb compatibility:
/dev/fd0[a-c] block file
/dev/rfd0[a-c] raw file
/vol/dev/diskette0 directory containing volume management character device file
/bol/dev/rdiskette0
directory containing the volume management raw character device file
/vol/dev/aliases/floppy0
symbolic link to the entry in /vol/dev/rdiskette0
x86
/kernel/drv/fd driver module
/kernel/drv/fd.conf configuration file for floppy driver
/kernel/drv/fdc floppy-controller driver module
/kernel/drv/fdc.conf
configuration file for the floppy-controller
/usr/include/sys/fdc.h
structs and definitions for x86 floppy devices
/usr/include/sys/fdmedia.h
structs and definitions for x86 floppy media
First Drive:
/dev/diskette device file
/dev/diskette0 device file
/dev/rdiskette raw device file
/dev/rdiskette0 raw device file
For ucb compatibility:
/dev/fd0[a-c] block file
/dev/rfd0[a-c] raw file
/vol/dev/diskette0 directory containing volume management character device file
/bol/dev/rdiskette0
directory containing the volume management raw character device file
/vol/dev/aliases/floppy0
symbolic link to the entry in /vol/dev/rdiskette0
Second Drive:
/dev/diskette1 device file
/dev/rdiskette1 raw device file
For ucb compatibility:
/dev/fd1[a-c] block file
/dev/rfd1[a-c] raw file
/vol/dev/diskette1 directory containing volume management character device file
/bol/dev/rdiskette1
directory containing the volume management raw character device file
/vol/dev/aliases/floppy1
symbolic link to the entry in /vol/dev/rdiskette1
SEE ALSO
fdformat(1), dd(1M), drvconfig(1M), vold(1M), read(2), write(2), driver.conf(4), dkio(7), fdio(7)
DIAGNOSTICS
fd<n>: <command name> failed (<sr1> <sr2> <sr3>)
The <command name> failed after several retries on drive <n>. The three hex values in parenthesis are the contents of status register 0, status register 1, and status register 2 of the Intel 8272, the Intel 82072, and the Intel 82077 Floppy Disk Controller on completion of the command as documented in the data sheet for that part. This error message is usually followed by one of the following, interpreting the bits of the status register:
fd<n>: not writable
fd<n>: crc error blk <block number>
There was a data error on <block number>.
fd<n>: bad format
fd<n>: timeout
fd<n>: drive not ready
fd<n>: unformatted diskette or no diskette in drive
fd<n>: block <block number> is past the end! (nblk=<total number of blocks>)
The operation tried to access a block number that is greater than the total number of blocks.
fd<n>: b_bcount 0x<op_size> not % 0x<sect_size>
The size of an operation is not a multiple of the sector size.
fd<n>: overrun/underrun
SPARC
Overrun/underrun errors occur when accessing a diskette while the system is heavily loaded. These errors are caused by a hardware limitation and cannot be fixed in the software.
NOTES
3.5" high density diskettes have 18 sectors per track and 5.25" high density diskettes have 15 sectors per track. They can cross a track (though not a cylinder) boundary without losing data, so when using dd(1M) to or from a diskette, you should specify bs=18k or multiples thereof for 3.5" diskettes, and bs=15k or multiples thereof for 5.25" diskettes.
The SPARC fd driver is not an unloadable module.
Under Solaris for x86, the configuration of the floppy drives is specified in CMOS configuration memory. Use the BIOS setup program or an EISA or MicroChannel configuration program for the system to define the diskette size and density/capacity for each installed drive. Note that MS-DOS may operate the floppy drives correctly, even though the CMOS configuration may be in error. Solaris for x86 relies on the CMOS configuration to be accurate.
SunOS 5.4 — Last change: 2 May 1994