freebsd-skq/sys/isa/fdreg.h
joerg b2bcdd0ab8 Long promised major enhancement set for the floppy disk driver:
. The main device node now supports automatic density selection for
  commonly used media densities.  So you can stuff your 1.44 MB and
  720 KB media into your drive and just access /dev/fd0, no questions
  asked.  It's all that easy, isn't it? :)

. Device density handling has been completely overhauled.  The old way
  of hardwired kernel density knowledge is no longer there.  Instead,
  the kernel now implements 16 subdevices per drive.  The first
  subdevice uses automatic density selection, while the remaining 15
  devices are freely programmable.  They can be assigned an arbitrary
  name of the form /dev/fd[:digit]+.[:digit:]{1,4}, where the second
  number is meant to either implement device names that are mnemonic
  for their raw capacity (as it used to be), or they can alternatively
  be created as "anonymous" devices like fd0.1 through fd0.15,
  depending on the taste of the administrator.  After creating a
  subdevice, it is initialized to the maximal native density of the
  respective drive type, so it needs to be customized for other
  densities by using fdcontrol(8).  Pseudo-partition devices (fd0a
  through fd0h) are still supported as symlinks.

. The old hack to use flags 0x1 to always assume drive 0 were there is
  no longer supported; this is now supposed to be done by wiring the
  devices down from the loader via device flags.  On IA32
  architectures, the first two drives are looked up in the CMOS
  configuration records though.  On PCMCIA (i. e., the Y-E Data
  controller of the Toshiba Libretto), a single drive is always
  assumed.

. Other specialities like disabling the FIFO and not probing the drive
  at boot-time are selected by per-controller or per-drive flags, too.

. Unit attentions (media has been changed) are supposed to be detected
  now; density autoselection only occurs after a unit attention.  (Can
  be turned off by a per-drive flag, this will cause each Fdopen() to
  perform the autoselection.)

. FM floppies can be handled now (on controllers that actually support
  it -- not all do these days).

. Fdopen() can be told to avoid density selection by setting
  O_NONBLOCK; this leaves the descriptor in a half-opened state where
  only a few ioctls are accepted.  This is necessary to run fdformat
  on a device that uses automatic density selection (since you cannot
  autoselect on an unformatted medium, obviously).

. Just differentiate between a plain old NE765 and the enhanced chips,
  but don't try more; the existing code was wrong and only misdetected
  the chips anyway.

BUGS and TODOs:

. All documentation update still needs to be done.

. Formatting not-so-standard format yields unpredictable results; i
  have yet to figure out why this happens.  "Standard" formats like
  720 and 1440 KB do work, however.

. rc scripts are needed to setup device nodes with nonstandard
  densities (like the old /dev/fdN.MMM we used to have).

. Obtaining device flags from the kernel environment doesn't work yet,
  thus currently only drives that are present in (IA32) CMOS are
  really detected.  Someone who knows the odds and ends about device
  flags is needed here, i can't figure out what i'm doing wrong.

. 2.88 MB still needs to be done.
2001-12-15 19:09:04 +00:00

72 lines
3.0 KiB
C

/*-
* Copyright (c) 1991 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: @(#)fdreg.h 7.1 (Berkeley) 5/9/91
* $FreeBSD$
*/
/*
* AT floppy controller registers and bitfields
*/
/* uses NEC765 controller */
#include <dev/ic/nec765.h>
/* registers */
#define FDOUT 2 /* Digital Output Register (W) */
#define FDO_FDSEL 0x03 /* floppy device select */
#define FDO_FRST 0x04 /* floppy controller reset */
#define FDO_FDMAEN 0x08 /* enable floppy DMA and Interrupt */
#define FDO_MOEN0 0x10 /* motor enable drive 0 */
#define FDO_MOEN1 0x20 /* motor enable drive 1 */
#define FDO_MOEN2 0x40 /* motor enable drive 2 */
#define FDO_MOEN3 0x80 /* motor enable drive 3 */
#define FDSTS 4 /* NEC 765 Main Status Register (R) */
#define FDDATA 5 /* NEC 765 Data Register (R/W) */
#define FDCTL 7 /* Control Register (W) */
/*
* The definitions for FDC_500KBPS etc. have been moved out to <sys/fdcio.h>
* since they need to be visible in userland. They cover the lower two bits
* of FDCTL when used for output.
*/
/*
* this is the secret PIO data port (offset from base)
*/
#define FDC_YE_DATAPORT 6
#define FDIN 7 /* Digital Input Register (R) */
#define FDI_DCHG 0x80 /* diskette has been changed */
/* requires drive and motor being selected */
/* is cleared by any step pulse to drive */