fd(7D) Devices fd(7D)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 capac‐
ity
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(7I)).
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 com‐
mand (see fdio(7I)).
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 com‐
pleted.
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(7I)).
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 charac‐
ter 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 charac‐
ter 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 charac‐
ter 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 ALSOfdformat(1), dd(1M), drvconfig(1M), read(2), write(2), driver.conf(4),
dkio(7I)fdio(7I)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 comple‐
tion 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 sys‐
tem 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(1M) 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 cor‐
rectly, even though the CMOS configuration may be in error. Solaris
(x86 Edition) relies on the CMOS configuration to be accurate.
SunOS 5.11 2 Mar 2007 fd(7D)
