floppycontrol - floppy driver configuration utility
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floppycontrol [-p] [--pollstate] [--printfdstate]
[-a operation-abort-threshold] [-c read-track-threshold]
[-r recalibrate-threshold] [-R reset-threshold]
[-e reporting-threshold] [-f] [-x] [-d drive][-F] [-T]
[-reset condition] [--debug] [--nodebug] [--messages]
[--nomessages] [--broken_dcl] [--working_dcl] [--inverted_dcl]
[--no_inverted_dcl] [--silent_dcl_clear] [--noisy_dcl_clear]
[-c cmos-type] [-hlt hlt] [-hut hut] [-srt srt] [-o spindown]
[-u spinup] [-s select-delay] [-rps rotations-per-second]
[-O spindown-offset] [-track max-tracks] [-timeout seconds]
[-C check-interval] [-n native-format]
[-autodetect autodetection-sequence] [-P] [--clrwerror]
The floppycontrol program is used to configure the floppy driver.
- Print a help screen.
- -d drive
- --drive drive
- Selects the drive to configure. The default is drive 0
The following floppycontrol options don't set a configuration parameter, but
perform a one-time action. They are available to anybody who has write access
to the drive
- Flushes (throws away) the dirty data buffers associated
with this drive.
- Ejects the disk out of the drive (Sparc). The dirty buffers
are first committed to disk before ejecting it. Fails if the disk is
- --reset condition
- Resets the FDC under condition . Condition may be
one of the following:
- resets the FDC only if a reset is needed anyways,
- resets the FDC also if a raw command has been performed
since the last reset, and
- resets the FDC unconditionally.
- This command may be needed after some failed raw commands
(see section fdrawcmd).
- Issues an end format ioctl. This might be needed after
exiting a fdformat in an unclean way. superformat is not subject to
- Print out the drive name of a floppy device. This is used
by the MAKEFLOPPIES script. The drive name is a letter (describing the
drive type) followed by the capacity of the format in bytes. The letter is
E for 3.5 ED drives, H for 3.5 HD drives, D for 3.5 DD drives, h for 5.25
HD drives and d for 5.25 DD drives. The drive type letter corresponds to
the oldest drive type supporting the format of this device node (not
necessarily the type of the drive referred by this node.) For the generic
format nodes (/dev/fd0 et al.) the name of "native format" of
the drive is printed, and for the default formats, if a generic format has
been redefined, its name becomes (null).
- Prints out the configuration of the drive. The names of the
various fields are the same as the names of the option to set them, see
- Prints out the cached internal state of the driver. The
first line lists various attributes about the disk:
- drive present
- disk present
- disk writable
- These are only updated when the drive is accessed.
- is the time when the motor became switched on for the last
- is the time when the drive became selected for the last
- is the time when the first read request after the last spin
- is the index of the autodetected format in the
autodetection sequence for this drive.
- is the cylinder where the drive head currently sits. If
this number is negative, it has the following meaning:
- -1 means that the driver doesn't know, but the controller
does (a seek command must be issued).
- -2 means that the controller doesn't know either, but is
sure that it not beyond the 80th track. The drive needs a
- -3 means that the head may be beyond the 80th track. The
drive needs two successive recalibrations, because at each recalibration,
the controller only issues 80 move head commands per recalibration.
- is the highest block number that has been read.
- is a boolean which is set when a sector that is not on
cylinder 0/head 0 has been read. These are used for smart invalidation of
the buffer cache on geometry change. The buffer cache of the drive is only
invalidated on geometry change when this change actually implies that a
block that has already been read changes position. This optimization is
useful for mtools which changes the geometry after reading the boot
- is roughly the number of disk changes noticed since boot.
Disk changes are noticed if the disk is actually changed, or if a flush
command is issued and for both cases if any I/O to/from the disk occurs.
(i.e. if you insert several disks, but don't do any I/O to them, the
generation number stays the same.)
- is number of open file descriptors for this drive. It is
always at least one, because floppycontrol's file descriptor is counted
- is format type (as derived from the minor device number)
which is currently being used.
- is date (in jiffies) when the drive was last checked for a
disk change, and a disk was actually in the drive.
- Polls the drive and then prints out the internal state of
the driver.(--Printstate only prints out the cached information without
actually polling the drive for a disk change.)
- Prints out the state of the controller where the target
drive is attached to.
- are the current values of those registers.
- is current data transfer rate
- is true if a raw command has been executed since the last
reset. If this is the case, a reset will be triggered when a drive on the
same FDC is next opened.
- is the value of the digital output register. The 4 high
bits are a bit mask describing which drives are spinning, the 2 low bits
describe the selected drive, bit 2 is used to reset the FDC, and bit 3
describes whether this FDC has hold of the interrupt and the DMA. If you
have two FDCs, bit 3 is only set on one of them.
- is the version of the FDC. See
`linux/include/linux/fdreg.h' for a listing of the FDC version
- is true if a reset needs to be issued to the FDC before
processing the next request.
- is true if this FDC needs configuration by the FD_CONFIGURE
- is set if the FDC understands the FD_CONFIGURE
- describes the perpendicular mode of this FDC. 0 is
non-perpendicular mode, 2 is HD perpendicular mode, 3 is ED perpendicular
mode, and 1 is unknown.
- is the address of the first I/O port of the FDC. Normally,
this is 0x3f0 for the first FDC and 0x370 for the second.
The following options handle the different available drive types, such as double
density vs. high density vs. extra density drives, and 5 1/4 drives vs 3 1/2
drives. Usually the drive type is stored in a non-volatile memory, called
CMOS, under the form of an integer ranging from 1 to 6.
Different drive types are able to handle and autodetect different formats
(different autodetection lists). They also have different "native format
name". The native format is the "usual" format with the highest
capacity supported by the drive. (For example 720KB on a double density 3 1/2
drive, and 1.2MB on a high density 5 1/4 drive.)
These settings are only changeable by the super user.
- -c cmos-type
- --cmos cmos-type
- Set the virtual CMOS type of the floppy drive. This is
- the physical CMOS type is wrong (this may happen with
BIOSes which use a non-standard mapping),
- you have more than two drives (the physical CMOS may only
describe up to two drives).
- you have a BIOS that allows swapping drives A: and B: for
Right now, this CMOS parameter is not used by the kernel, except for feeding it
back to other applications (for instance superformat, floppymeter or
MAKEFLOPPIES). It is also possible to supply a virtual CMOS type with the cmos
boot option (see section Boottime configuration). If possible, I recommend you
use the boot option, rather than floppycontrol, because the boot option also
sets any parameters derived from the CMOS type, such as the autodetection list
and the native format, whereas floppycontrol does not.
- -A autodetect-seq
- --autodetect autodetect-seq
- Set the autodetection sequence (see section Autodetection)
The autodetection sequence is a comma-separated list of at most eight
format descriptors. Each format descriptor is a format number optionally
followed by the letter t. For drive 0, the format number is the minor
device number divided by 4. The autodetection sequence is used by the
driver to find out the format of a newly inserted disk. The formats are
tried one after the other, and the first matching format is retained. To
test the format, the driver tries to read the first sector on the first
track on the first head when t is not given, or the whole first track when
t is given. Thus, autodetection cannot detect the number of tracks.
However, this information is contained in the boot sector, which is now
accessible. The boot sector can then be used by mtools to configure the
correct number of tracks.
means to try out the formats whose minor device numbers are 28 (1.44M), 16
(720KB), 96 (1.76MB), and 100 (1.92MB), in this order. For the 1.76MB
format, try to read the whole track at once.
- Reading the whole track at once allows you to distinguish
between two formats which differ only in the number of sectors. (The
format with the most sectors must be tried first.) If you use mtools, you
do not need this feature, as mtools can figure out the number of sectors
without any help from the floppy driver, by looking at the boot
- Reading the whole track at once may also speed up the first
read by 200 milliseconds. However, if, on the other hand, you try to read
a disk which has less sectors than the format, you lose some time.
- I suggest that you put the most often used format in the
first place (barring other constraints), as each format that is tried out
takes 400 milliseconds.
- -n native-format
- --native_format native-format
- Set the native format of this drive. The native format of a
drive is the highest standard format available for this drive. (Example:
For a 5 1/4 HD drive it is the usual 1200K format.) This is format is used
to make up the format name for the generic device (which is the name of
the native format). This drive name is read back from the kernel by the
MAKEFLOPPIES script which uses it to decide which device nodes to
- Assumes that the disk change line of the drive is broken.
If this is set, disk changes are assumed to happen whenever the device
node is first opened. The physical disk change line is ignored.
- This option should be used if disk changes are either not
detected at all, or if disk changes are detected when the disk was
actually not changed. If this option fixes the problem, I'd recommend that
you try to trace the root cause of the problem. Indeed, this options
results in reduced performance due to spurious cache flushes.
- The following hardware problems may lead to a bad disk
- If the floppy cable is not inserted straight, or if it is
kinked, the disk change line is likely to suffer, as it is on the edge of
the cable. Gently press on both connectors of the cable (drive and
controller) to insure that all wires make contact. Visually inspect the
cable, and if it shows obvious traces of damage, get a new one.
- On some drives, the locations disk change line may be
chosen by jumper. Make sure that your floppy controller and your drive
agree on which line is the disk change line.
- Some older drives (mostly double density 5 1/4 drives)
don't have a disk change line. In this case, you have no choice other than
to leave the broken_dcl option on.
- Assumes that the disk change line works all right.
Switching from broken to working may lead to unexpected results after the
first disk change.
- Assumes that this disk drive uses an inverted disk change
line. Apparently this is the case for IBM thinkpads.
- Assumes that this drive follows the standard convention for
the disk change line.
- Switches off silent disk change line clearing for this
This section describes how to configure drive timings. To set these parameters,
you need superuser privileges. All times are in "jiffy" units (10
milliseconds), unless otherwise specified.
- --hlt hlt
- Set the head load time (in microseconds) for this floppy
drive. The head load time describes how long the floppy controller waits
after seeking or changing heads before allowing access to a track.
- --hut hut
- Set the head unload time (in microseconds) for this floppy
drive. The head unload time describes how long the floppy controller waits
after an access before directing its attention to the other head, or
- --srt srt
- Set the step rate (in microseconds) for this floppy drive.
The step rate describes how long the drive head stays on one cylinder when
seeking. Setting this value to low (too fast seeks) may make seeks fail,
because the motor doesn't follow fast enough.
- -u spinup-time
- --spinup spinup-time
- Set the spinup time of the floppy drive. In order to do
read or write to the floppy disk, it must spin. It takes a certain time
for the motor to reach enough speed to read or write. This parameter
describes this time. The floppy driver doesn't try to access the drive
before the spinup time has elapsed. With modern controllers, you may set
this time to zero, as the controller itself enforces the right delay.
- -o spindown-time
- --spindown spindown-time
- Set the spindown time of this floppy drive. The motor is
not stopped immediately after the operation completes, because there might
be more operations following. The spindown time is the time the driver
waits before switching off the motor.
- -O spindown-offset
- --spindown_offset spindown-offset
- Set the spindown offset of this floppy drive. This
parameter is used to set the position in which the disk stops. This is
useful to minimize the next access time. (If the first sector is just near
the head at the very moment at which the disk has reached enough speed,
you win 200 milliseconds against the most unfavorable situation).
- This is done by clocking the time where the first I/O
request completes, and using this time to calculate the current position
of the disk.
- -s select-delay
- --select_delay select-delay
- Set the select delay of this floppy drive. This is
the delay that the driver waits after selecting the drive and issuing the
first command to it. For modern controllers/drives, you may set this to
- -C check-interval
- --checkfreq check-interval
- Set the maximal disk change check interval. The disk change
line is checked whenever a read or write to the device is issued, and it
has not been checked for more than interval jiffies.
This subsection describes how to switch the available debugging messages on and
- Switch debugging output on. The debugging information
includes timing information. This option might be useful to fine-tune the
timing options for your local setups. (But for most normal purposes, the
default values are good enough.)
- Switch debugging output off.
- Print informational messages after autodetection, geometry
parameter clearing and dma over/underruns.
- Don't print informational messages after these events.
The following options configure the behavior of the floppy driver in case of
read/write errors. They may be used by any user who has write privileges for
the drive. Whenever the floppy driver encounters an error, a retry counter is
incremented. If the value of this counter gets bigger than the thresholds
described below, the corresponding actions are performed at the next retry.
The counter is reset when the read or write finally terminates, whether
successfully or not.
- -a operation-abort-threshold
- --abort operation-abort-threshold
- Tell the floppy driver to stop trying to read/write a
sector after operation-abort-threshold retries, and signal the I/O
error to the user.
- -t read-track-threshold
- --readtrack read-track-threshold
- Tell the floppy driver to switch from track-reading mode to
sector-at-a-time-mode after read-track-threshold retries.
- -r recalibrate-threshold
- --recalibrate recalibrate-threshold
- Tell the floppy driver to recalibrate the drive after
- -R reset-threshold
- --reset reset-threshold
- Tell the floppy driver to reset the controller after
reset-threshold retries. After a controller reset, the floppy
driver also recalibrates all drives connected to that controller.
- -e error-report-threshold
- --reporting error-report-threshold
- Tell the floppy driver to start printing error messages to
the console after error-report-threshold retries.
Due to the buffer cache, write errors cannot always be reported to the writing
user program as soon as the write system call returns. Indeed, the actual
writing may take place much later. If a write error is encountered, the floppy
driver stores information about it in its per drive write error structure.
This write error structure stays until explicitly cleared. It can for example
be queried by a backup program which wants to make sure that the data has been
- Clears the write error structure.
- Prints the contents of the write error structure:
- is a count of how many write errors have occurred since the
structure was last cleared.
- is the maximal number of retries that were needed to
complete an operation (reads, writes and formats).
- is where the first (chronologically) write error
- is the disk change generation in which did the first write
error occurred. The disk change generation is a number which is
incremented at each disk change.
- are similar.
This subsection lists per drive configuration options, which don't fit in any
other category. They are available only to the superuser:
- --tracks max-tracks
- Set the maximal numbers of physical tracks that this drive
may handle. If you have a drive which is only able to handle 80 tracks
(making strange noises when you try to format or read a disk with more
than 80 tracks), use this option to prevent unprivileged users of damaging
your drive by repeatedly reading disks with more than 80 tracks.
- If you trust your users and your disks, you don't need
this. With most drives you don't need to worry anyways. See section More
cylinders, for details.
- -i sector-interleave
- --interleave sector-interleave
- Set the number of sectors beyond which sector interleaving
will be used. This option will only be used by the FDFMTTRK ioctl. The
fdformat command, which is now considered obsolete, uses FDFMTTRK ioctl,
but superformat does not.
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