FD(4D) FD(4D)

NAME

fd, fdc - drivers for floppy disks and floppy disk controllers

SYNOPSIS

SPARC

/dev/diskette0


/dev/rdiskette0


x86
/dev/diskette[0-1]


/dev/rdiskette[0-1]

DESCRIPTION

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
based 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 (/dev/diskette*) 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 (/dev/rdiskette*) 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 larger blocking
factors are used. A blocking factor of no less than 8 Kbytes is
recommended. See the Notes section, below, for information on the number
of sectors per track.

3.5 Diskettes"
For 3.5" double-sided diskettes, the following densities are supported:

SPARC

1.7 Mbyte density
80 cylinders, 21 sectors per track, 1.7 Mbyte
capacity


high density
80 cylinders, 18 sectors per track, 1.44 Mbyte
capacity


double density
80 cylinders, 9 sectors per track, 720 Kbyte
capacity


x86
extended density
80 cylinders, 36 sectors per track, 2.88 Mbyte
capacity


1.7 Mbyte density
80 cylinders, 21 sectors per track, 1.7 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 on x86 platforms, the densities listed
below are supported:

SPARC

5.25" diskettes are not supported on SPARC platforms.

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(4I)).


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(4I)).


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(4I)).


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).


X86 CONFIGURATION
The driver attempts to initialize itself using the information found in
the configuration file, /platform/i86pc/kernel/drv/fd.conf.

name="fd" parent="fdc" unit=0;
name="fd" parent="fdc" unit=1;

FILES

SPARC

/platform/sun4u/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


/dev/diskette0
directory containing volume management character
device file


/dev/rdiskette0
directory containing the volume management raw
character device file


/dev/aliases/floppy0
symbolic link to the entry in /dev/rdiskette0


x86
/platform/i86pc/kernel/drv/fd

driver module


/platform/i86pc/kernel/drv/fd.conf

configuration file for floppy driver


/platform/i86pc/kernel/drv/fdc

floppy-controller driver module


/platform/i86pc/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


x86 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


/dev/diskette0
directory containing volume management character
device file


/dev/rdiskette0
directory containing the volume management raw
character device file


/dev/aliases/floppy0
symbolic link to the entry in /dev/rdiskette0


x86 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


/dev/diskette1
directory containing volume management character
device file


/dev/rdiskette1
directory containing the volume management raw
character device file


/dev/aliases/floppy1
symbolic link to the entry in /dev/rdiskette1

SEE ALSO

fdformat(1), dd(8), drvconfig(8), read(2), write(2), driver.conf(5),
dkio(4I) fdio(4I)

DIAGNOSTICS

All Platforms

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


fd<n>:
host bus error. There was a hardware error on a system bus.

SPARC Only

Overrun/underrun errors occur when accessing a diskette while the system
is heavily loaded. Decrease the load on the system and retry the diskette
access.

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(8)
or read(2)/write(2) calls to or from the raw 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 (x86 Edition), the configuration of the floppy drives is
specified in CMOS configuration memory. Use the BIOS setup 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
(x86 Edition) relies on the CMOS configuration to be accurate.


March 2, 2007 FD(4D)