fd(7D)
NAME
fd, fdc - drivers for floppy disks and floppy disk controll-
ers
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 compa-
tible 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; there-
fore 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 capa-
city
double density
80 cylinders, 9 sectors per track, 720 Kbyte capacity
x86
extended density
80 cylinders, 36 sectors per track, 2.88 Mbyte capa-
city
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 capa-
city
double density
80 cylinders, 9 sectors per track, 760 Kbyte capacity
5.25" Diskettes
For 5.25" double-sided diskettes on x86 platforms, the den-
sities 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 sec-
tor), 320 Kbyte capacity
double density
40 cylinders, 4 sectors per track (1024 bytes per sec-
tor), 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 applica-
tion 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 command (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 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(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 informa-
tion 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 con-
trollers
/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 dev-
ice file
/vol/dev/rdiskette0
directory containing the volume management raw charac-
ter device file
/vol/dev/aliases/floppy0
symbolic link to the entry in /vol/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
/vol/dev/diskette0
directory containing volume management character dev-
ice file
/vol/dev/rdiskette0
directory containing the volume management raw charac-
ter device file
/vol/dev/aliases/floppy0
symbolic link to the entry in /vol/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
/vol/dev/diskette1
directory containing volume management character dev-
ice file
/vol/dev/rdiskette1
directory containing the volume management raw charac-
ter 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(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 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(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 mul-
tiples 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 or an EISA 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 (x86 Edi-
tion) relies on the CMOS configuration to be accurate.
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