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.

2 files changed, 397 insertions, 3 deletions

diff --git a/usr.sbin/fdread/fdutil.c b/usr.sbin/fdread/fdutil.c
index fb61b30..9990790 100644
--- a/usr.sbin/fdread/fdutil.c
+++ b/usr.sbin/fdread/fdutil.c
@@ -26,16 +26,23 @@
  * $FreeBSD$
  */
 
-#include <sys/types.h>
+#include <dev/ic/nec765.h>
+
 #include <sys/fdcio.h>
 
+#include <err.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
-
-#include <dev/ic/nec765.h>
+#include <sysexits.h>
 
 #include "fdutil.h"
 
+/*
+ * Decode the FDC status pointed to by `fdcsp', and print a textual
+ * translation to stderr.  If `terse' is false, the numerical FDC
+ * register status is printed, too.
+ */
 void
 printstatus(struct fdc_status *fdcsp, int terse)
 {
@@ -78,3 +85,382 @@ printstatus(struct fdc_status *fdcsp, int terse)
 	fputs(msgbuf, stderr);
 }
 
+static struct fd_type fd_types_288m[] =
+{
+#if 0
+{ 36,2,0xFF,0x1B,80,5760,FDC_1MBPS,  2,0x4C,1,1,FL_MFM|FL_PERPND } /*2.88M*/
+#endif
+{ 21,2,0xFF,0x04,82,3444,FDC_500KBPS,2,0x0C,2,0,FL_MFM }, /* 1.72M */
+{ 18,2,0xFF,0x1B,82,2952,FDC_500KBPS,2,0x6C,1,0,FL_MFM }, /* 1.48M */
+{ 18,2,0xFF,0x1B,80,2880,FDC_500KBPS,2,0x6C,1,0,FL_MFM }, /* 1.44M */
+{ 15,2,0xFF,0x1B,80,2400,FDC_500KBPS,2,0x54,1,0,FL_MFM }, /*  1.2M */
+{ 10,2,0xFF,0x10,82,1640,FDC_250KBPS,2,0x2E,1,0,FL_MFM }, /*  820K */
+{ 10,2,0xFF,0x10,80,1600,FDC_250KBPS,2,0x2E,1,0,FL_MFM }, /*  800K */
+{  9,2,0xFF,0x20,80,1440,FDC_250KBPS,2,0x50,1,0,FL_MFM }, /*  720K */
+};
+
+static struct fd_type fd_types_144m[] =
+{
+{ 21,2,0xFF,0x04,82,3444,FDC_500KBPS,2,0x0C,2,0,FL_MFM }, /* 1.72M */
+{ 18,2,0xFF,0x1B,82,2952,FDC_500KBPS,2,0x6C,1,0,FL_MFM }, /* 1.48M */
+{ 18,2,0xFF,0x1B,80,2880,FDC_500KBPS,2,0x6C,1,0,FL_MFM }, /* 1.44M */
+{ 15,2,0xFF,0x1B,80,2400,FDC_500KBPS,2,0x54,1,0,FL_MFM }, /*  1.2M */
+{ 10,2,0xFF,0x10,82,1640,FDC_250KBPS,2,0x2E,1,0,FL_MFM }, /*  820K */
+{ 10,2,0xFF,0x10,80,1600,FDC_250KBPS,2,0x2E,1,0,FL_MFM }, /*  800K */
+{  9,2,0xFF,0x20,80,1440,FDC_250KBPS,2,0x50,1,0,FL_MFM }, /*  720K */
+};
+
+static struct fd_type fd_types_12m[] =
+{
+{ 15,2,0xFF,0x1B,80,2400,FDC_500KBPS,2,0x54,1,0,FL_MFM }, /*  1.2M */
+{  8,3,0xFF,0x35,77,1232,FDC_500KBPS,2,0x74,1,0,FL_MFM }, /* 1.23M */
+{ 18,2,0xFF,0x02,82,2952,FDC_500KBPS,2,0x02,2,0,FL_MFM }, /* 1.48M */
+{ 18,2,0xFF,0x02,80,2880,FDC_500KBPS,2,0x02,2,0,FL_MFM }, /* 1.44M */
+{ 10,2,0xFF,0x10,82,1640,FDC_300KBPS,2,0x2E,1,0,FL_MFM }, /*  820K */
+{ 10,2,0xFF,0x10,80,1600,FDC_300KBPS,2,0x2E,1,0,FL_MFM }, /*  800K */
+{  9,2,0xFF,0x20,80,1440,FDC_300KBPS,2,0x50,1,0,FL_MFM }, /*  720K */
+{  9,2,0xFF,0x23,40, 720,FDC_300KBPS,2,0x50,1,0,FL_MFM|FL_2STEP }, /* 360K */
+{  8,2,0xFF,0x2A,80,1280,FDC_300KBPS,2,0x50,1,0,FL_MFM }, /*  640K */
+};
+
+static struct fd_type fd_types_720k[] =
+{
+{  9,2,0xFF,0x20,80,1440,FDC_250KBPS,2,0x50,1,0,FL_MFM }, /*  720K */
+};
+
+static struct fd_type fd_types_360k[] =
+{
+{  9,2,0xFF,0x2A,40, 720,FDC_250KBPS,2,0x50,1,0,FL_MFM }, /*  360K */
+};
+
+/*
+ * Parse a format string, and fill in the parameter pointed to by `out'.
+ *
+ * sectrac,secsize,datalen,gap,ncyls,speed,heads,f_gap,f_inter,offs2,flags[...]
+ *
+ * sectrac = sectors per track
+ * secsize = sector size in bytes
+ * datalen = length of sector if secsize == 128
+ * gap     = gap length when reading
+ * ncyls   = number of cylinders
+ * speed   = transfer speed 250/300/500/1000 KB/s
+ * heads   = number of heads
+ * f_gap   = gap length when formatting
+ * f_inter = sector interleave when formatting
+ * offs2   = offset of sectors on side 2
+ * flags   = +/-mfm | +/-2step | +/-perpend
+ *             mfm - use MFM recording
+ *             2step - use 2 steps between cylinders
+ *             perpend - user perpendicular (vertical) recording
+ *
+ * Any omitted value will be passed on from parameter `in'.
+ */
+void
+parse_fmt(const char *s, enum fd_drivetype type,
+	  struct fd_type in, struct fd_type *out)
+{
+	int i, j;
+	const char *cp;
+	char *s1;
+
+	*out = in;
+
+	for (i = 0;; i++) {
+		if (s == 0)
+			break;
+
+		if ((cp = strchr(s, ',')) == 0) {
+			s1 = strdup(s);
+			if (s1 == NULL)
+				abort();
+			s = 0;
+		} else {
+			s1 = malloc(cp - s + 1);
+			if (s1 == NULL)
+				abort();
+			memcpy(s1, s, cp - s);
+			s1[cp - s] = 0;
+
+			s = cp + 1;
+		}
+		if (strlen(s1) == 0) {
+			free(s1);
+			continue;
+		}
+
+		switch (i) {
+		case 0:		/* sectrac */
+			if (getnum(s1, &out->sectrac))
+				errx(EX_USAGE,
+				     "bad numeric value for sectrac: %s", s1);
+			break;
+
+		case 1:		/* secsize */
+			if (getnum(s1, &j))
+				errx(EX_USAGE,
+				     "bad numeric value for secsize: %s", s1);
+			if (j == 128) out->secsize = 0;
+			else if (j == 256) out->secsize = 1;
+			else if (j == 512) out->secsize = 2;
+			else if (j == 1024) out->secsize = 3;
+			else
+				errx(EX_USAGE, "bad sector size %d", j);
+			break;
+
+		case 2:		/* datalen */
+			if (getnum(s1, &j))
+				errx(EX_USAGE,
+				     "bad numeric value for datalen: %s", s1);
+			if (j >= 256)
+				errx(EX_USAGE, "bad datalen %d", j);
+			out->datalen = j;
+			break;
+
+		case 3:		/* gap */
+			if (getnum(s1, &out->gap))
+				errx(EX_USAGE,
+				     "bad numeric value for gap: %s", s1);
+			break;
+
+		case 4:		/* ncyls */
+			if (getnum(s1, &j))
+				errx(EX_USAGE,
+				     "bad numeric value for ncyls: %s", s1);
+			if (j > 85)
+				errx(EX_USAGE, "bad # of cylinders %d", j);
+			out->tracks = j;
+			break;
+
+		case 5:		/* speed */
+			if (getnum(s1, &j))
+				errx(EX_USAGE,
+				     "bad numeric value for speed: %s", s1);
+			switch (type) {
+			default:
+				abort(); /* paranoia */
+
+			case FDT_360K:
+			case FDT_720K:
+				if (j == 250)
+					out->trans = FDC_250KBPS;
+				else {
+				  badspeed:
+					errx(EX_USAGE, "bad speed %d", j);
+				}
+				break;
+
+			case FDT_12M:
+				if (j == 300)
+					out->trans = FDC_300KBPS;
+				else if (j == 500)
+					out->trans = FDC_500KBPS;
+				else
+					goto badspeed;
+				break;
+
+			case FDT_288M:
+				if (j == 1000)
+					out->trans = FDC_1MBPS;
+				/* FALLTHROUGH */
+			case FDT_144M:
+				if (j == 250)
+					out->trans = FDC_250KBPS;
+				else if (j == 500)
+					out->trans = FDC_500KBPS;
+				else
+					goto badspeed;
+				break;
+			}
+			break;
+
+		case 6:		/* heads */
+			if (getnum(s1, &j))
+				errx(EX_USAGE,
+				     "bad numeric value for heads: %s", s1);
+			if (j == 1 || j == 2)
+				out->heads = j;
+			else
+				errx(EX_USAGE, "bad # of heads %d", j);
+			break;
+
+		case 7:		/* f_gap */
+			if (getnum(s1, &out->f_gap))
+				errx(EX_USAGE,
+				     "bad numeric value for f_gap: %s", s1);
+			break;
+
+		case 8:		/* f_inter */
+			if (getnum(s1, &out->f_inter))
+				errx(EX_USAGE,
+				     "bad numeric value for f_inter: %s", s1);
+			break;
+
+		case 9:		/* offs2 */
+			if (getnum(s1, &out->offset_side2))
+				errx(EX_USAGE,
+				     "bad numeric value for offs2: %s", s1);
+			break;
+
+		default:
+			if (strcmp(s1, "+mfm") == 0)
+				out->flags |= FL_MFM;
+			else if (strcmp(s1, "-mfm") == 0)
+				out->flags &= ~FL_MFM;
+			else if (strcmp(s1, "+2step") == 0)
+				out->flags |= FL_2STEP;
+			else if (strcmp(s1, "-2step") == 0)
+				out->flags &= ~FL_2STEP;
+			else if (strcmp(s1, "+perpnd") == 0)
+				out->flags |= FL_PERPND;
+			else if (strcmp(s1, "-perpnd") == 0)
+				out->flags &= ~FL_PERPND;
+			else
+				errx(EX_USAGE, "bad flag: %s", s1);
+			break;
+		}
+		free(s1);
+	}
+
+	out->size = out->tracks * out->heads * out->sectrac *
+		(128 << out->secsize) / 512;
+}
+
+/*
+ * Print a textual translation of the drive (density) type described
+ * by `in' to stdout.  The string uses the same form that is parseable
+ * by parse_fmt().
+ */
+void
+print_fmt(struct fd_type in)
+{
+	int secsize, speed;
+
+	secsize = 128 << in.secsize;
+	switch (in.trans) {
+	case FDC_250KBPS:	speed = 250; break;
+	case FDC_300KBPS:	speed = 300; break;
+	case FDC_500KBPS:	speed = 500; break;
+	case FDC_1MBPS:		speed = 1000; break;
+	default:		speed = 1; break;
+	}
+
+	printf("%d,%d,%#x,%#x,%d,%d,%d,%#x,%d,%d",
+	       in.sectrac, secsize, in.datalen, in.gap, in.tracks,
+	       speed, in.heads, in.f_gap, in.f_inter, in.offset_side2);
+	if (in.flags & FL_MFM)
+		printf(",+mfm");
+	if (in.flags & FL_2STEP)
+		printf(",+2step");
+	if (in.flags & FL_PERPND)
+		printf(",+perpnd");
+	putc('\n', stdout);
+}
+
+/*
+ * Based on `size' (in kilobytes), walk through the table of known
+ * densities for drive type `type' and see if we can find one.  If
+ * found, return it (as a pointer to static storage), otherwise return
+ * NULL.
+ */
+struct fd_type *
+get_fmt(int size, enum fd_drivetype type)
+{
+	int i, n;
+	struct fd_type *fdtp;
+
+	switch (type) {
+	default:
+		return (0);
+
+	case FDT_360K:
+		fdtp = fd_types_360k;
+		n = sizeof fd_types_360k / sizeof(struct fd_type);
+		break;
+
+	case FDT_720K:
+		fdtp = fd_types_720k;
+		n = sizeof fd_types_720k / sizeof(struct fd_type);
+		break;
+
+	case FDT_12M:
+		fdtp = fd_types_12m;
+		n = sizeof fd_types_12m / sizeof(struct fd_type);
+		break;
+
+	case FDT_144M:
+		fdtp = fd_types_144m;
+		n = sizeof fd_types_144m / sizeof(struct fd_type);
+		break;
+
+	case FDT_288M:
+		fdtp = fd_types_288m;
+		n = sizeof fd_types_288m / sizeof(struct fd_type);
+		break;
+	}
+
+	for (i = 0; i < n; i++, fdtp++)
+		if (fdtp->size / 2 == size)
+			return (fdtp);
+
+	return (0);
+}
+
+/*
+ * Parse a number from `s'.  If the string cannot be converted into a
+ * number completely, return -1, otherwise 0.  The result is returned
+ * in `*res'.
+ */
+int
+getnum(const char *s, int *res)
+{
+	unsigned long ul;
+	char *cp;
+
+	ul = strtoul(s, &cp, 0);
+	if (*cp != '\0')
+	  return (-1);
+
+	*res = (int)ul;
+	return (0);
+}
+
+/*
+ * Return a short name and a verbose description for the drive
+ * described by `t'.
+ */
+void
+getname(enum fd_drivetype t, const char **name, const char **descr)
+{
+
+	switch (t) {
+	default:
+		*name = "unknown";
+		*descr = "unknown drive type";
+		break;
+
+	case FDT_360K:
+		*name = "360K";
+		*descr = "5.25\" double-density";
+		break;
+
+	case FDT_12M:
+		*name = "1.2M";
+		*descr = "5.25\" high-density";
+		break;
+
+	case FDT_720K:
+		*name = "720K";
+		*descr = "3.5\" double-density";
+		break;
+
+	case FDT_144M:
+		*name = "1.44M";
+		*descr = "3.5\" high-density";
+		break;
+
+	case FDT_288M:
+		*name = "2.88M";
+		*descr = "3.5\" extra-density";
+		break;
+	}
+}
diff --git a/usr.sbin/fdread/fdutil.h b/usr.sbin/fdread/fdutil.h
index f499390..a093228 100644
--- a/usr.sbin/fdread/fdutil.h
+++ b/usr.sbin/fdread/fdutil.h
@@ -26,4 +26,12 @@
  * $FreeBSD$
  */
 
+
 void	printstatus(struct fdc_status *fdcsp, int terse);
+void	parse_fmt(const char *, enum fd_drivetype,
+		     struct fd_type, struct fd_type *);
+struct	fd_type *get_fmt(int, enum fd_drivetype);
+void	print_fmt(struct fd_type);
+int	getnum(const char *, int *);
+void	getname(enum fd_drivetype, const char **, const char **);
+