initial import of NetBSD tree

3 files changed, 952 insertions, 0 deletions

diff --git a/sbin/fdisk/Makefile b/sbin/fdisk/Makefile
new file mode 100644
index 00000000000..4f9961cc10a
--- /dev/null
+++ b/sbin/fdisk/Makefile
@@ -0,0 +1,7 @@
+#	$NetBSD: Makefile,v 1.4 1995/03/18 14:55:33 cgd Exp $
+
+PROG=	fdisk 
+SRCS=	fdisk.c
+MAN=	fdisk.8
+
+.include <bsd.prog.mk>
diff --git a/sbin/fdisk/fdisk.8 b/sbin/fdisk/fdisk.8
new file mode 100644
index 00000000000..6d3a37b4c9b
--- /dev/null
+++ b/sbin/fdisk/fdisk.8
@@ -0,0 +1,173 @@
+.\"	$NetBSD: fdisk.8,v 1.8 1995/03/18 14:55:34 cgd Exp $
+.\"
+.Dd April 4, 1993
+.Dt FDISK 8
+.\" .Os BSD 4
+.Sh NAME
+.Nm fdisk
+.Nd DOS partition maintenance program
+.Sh SYNOPSIS
+.Nm
+.Op Fl aiu
+.Op Ar device
+.Sh PROLOGUE
+In order for the BIOS to boot the kernel, certain conventions must be
+adhered to.
+Sector 0 of the disk must contain boot code, a partition table, and a
+magic number.
+BIOS partitions can be used to break the disk up into several pieces.
+The BIOS brings in sector 0, verifies the magic number, and begins
+executing the code at the first byte.
+This code is turn searches the DOS partition table for an `active'
+partition.
+If one is found, the boot block from that partition is loaded and replaces
+the original boot block.
+Under DOS, you could have one or more partitions with one active.
+The DOS
+.Nm
+program can be used to divide space on the disk into partitions and set
+one active.
+.Pp
+The NetBSD program
+.Nm
+serves a similar purpose to the DOS program.
+When called with no arguments, it prints the sector 0 partition table.
+An example follows:
+.Bd -literal
+	******* Working on device /dev/rwd0d *******
+	parameters extracted from in-core disklabel are:
+	cylinders=769 heads=15 sectors/track=33 (495 sectors/cylinder)
+
+	parameters to be used for BIOS calculations are:
+	cylinders=769 heads=15 sectors/track=33 (495 sectors/cylinder)
+		
+	Warning: BIOS sector numbering starts with sector 1
+	Information from DOS bootblock is:
+	The data for partition 0 is:
+	sysid 165 (NetBSD)
+    	    start 495, size 380160 (185 MB), flag 0
+		beg: cylinder    1, head   0, sector  1
+		end: cylinder  768, head  14, sector 33
+	The data for partition 1 is:
+	sysid 164 (unknown)
+    	    start 378180, size 2475 (1 MB), flag 0
+		beg: cylinder  764, head   0, sector  1
+		end: cylinder  768, head  14, sector 33
+	The data for partition 2 is:
+	<UNUSED>
+	The data for partition 3 is:
+	sysid 99 (ISC UNIX, other System V/386, GNU HURD or Mach)
+    	    start 380656, size 224234 (109 MB), flag 80
+		beg: cylinder  769, head   0, sector  2
+		end: cylinder  197, head  14, sector 33
+.Ed
+.Pp
+The disk is divided into three partitions that happen to fill the disk.
+The second partition overlaps the end of the first.
+(Used for debugging purposes)
+.Bl -tag -width "cyl, sector and head"
+.It Em "sysid"
+is used to label the partition.  NetBSD reserves the
+magic number 165 decimal (A5 in hex).
+.It Em "start and size"
+fields provide the start address
+and size of a partition in sectors.
+.It Em "flag 80"
+specifies that this is the active partition.
+.It Em "cyl, sector and head"
+fields are used to specify the beginning address
+and end address for the partition.
+.It Em "Note:"
+these numbers are calculated using BIOS's understanding of the disk geometry
+and saved in the bootblock.
+.El
+.Pp
+The flags
+.Fl i
+or
+.Fl u
+are used to indicate that the partition data is to be updated.
+The
+.Nm
+program will enter a conversational mode.
+This mode is designed not to change any data unless you explicitly tell it to;
+.Nm
+selects defaults for its questions to guarantee that behavior.
+.Pp
+It displays each partition and asks if you want to edit it.
+If you reply affirmatively,
+it will step through each field showing the old value
+and asking for a new one.
+When you are done with a partition,
+.Nm
+will display the information again and ask if it is correct.
+.Nm
+will then procede to the next entry.
+.Pp
+Getting the
+.Em cyl, sector,
+and
+.Em head
+fields correct is tricky.
+So by default,
+they will be calculated for you;
+you can specify them if you choose.
+.Pp
+After all the partitions are processed,
+you are given the option to change the
+.Em active
+partition.
+To change only the
+.Em active
+partition, you can use the
+.Fl a
+flag instead.
+.Pp
+Finally,
+when the all the data for the first sector has been accumulated,
+.Nm
+will ask if you really want to rewrite sector 0.
+Only if you reply affirmatively to this question will
+.Nm
+write anything to the disk.
+.Pp
+The difference between the
+.Fl u
+flag and
+.Fl i
+flag is that
+the
+.Fl u
+flag just edits the fields as they appear on the disk, while the
+.Fl i
+flag is used to `initialize' sector 0.
+The
+.Fl i
+flag instructs
+.Nm
+to start by making the first 3 partitions empty, setting the last partition
+to use the whole disk for NetBSD, and marking the last partition active.
+.Sh NOTES
+The automatic calculation of starting cylinder etc. uses
+a set of figures that represent what the BIOS thinks is the
+geometry of the drive.
+These figures are by default taken from the incore disklabel, but
+.Nm
+gives you an opportunity to change them.
+This allows the user to create a bootblock that can work with drives
+that use geometry translation under the BIOS.
+.Pp
+If you hand craft your disk layout,
+please make sure that the NetBSD partition starts on a cylinder boundary.
+(This restriction may be changed in the future.)
+.Pp
+Editing an existing partition is risky, and may cause you to
+lose all the data in that partition.
+.Pp
+You should run this program interactively once or twice to see how it works.
+This is completely safe as long as you answer the last question in the negative.
+.Sh SEE ALSO
+.Xr disklabel 8
+.Sh BUGS
+There are subtleties that the program detects that are not explained in
+this manual page.
diff --git a/sbin/fdisk/fdisk.c b/sbin/fdisk/fdisk.c
new file mode 100644
index 00000000000..60cfe1bc2ab
--- /dev/null
+++ b/sbin/fdisk/fdisk.c
@@ -0,0 +1,772 @@
+/*	$NetBSD: fdisk.c,v 1.11 1995/10/04 23:11:19 ghudson Exp $	*/
+
+/*
+ * Mach Operating System
+ * Copyright (c) 1992 Carnegie Mellon University
+ * All Rights Reserved.
+ *
+ * Permission to use, copy, modify and distribute this software and its
+ * documentation is hereby granted, provided that both the copyright
+ * notice and this permission notice appear in all copies of the
+ * software, derivative works or modified versions, and any portions
+ * thereof, and that both notices appear in supporting documentation.
+ *
+ * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
+ * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
+ * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ *
+ * Carnegie Mellon requests users of this software to return to
+ *
+ *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
+ *  School of Computer Science
+ *  Carnegie Mellon University
+ *  Pittsburgh PA 15213-3890
+ *
+ * any improvements or extensions that they make and grant Carnegie Mellon
+ * the rights to redistribute these changes.
+ */
+
+#ifndef lint
+static char rcsid[] = "$NetBSD: fdisk.c,v 1.11 1995/10/04 23:11:19 ghudson Exp $";
+#endif /* not lint */
+
+#include <sys/types.h>
+#include <sys/disklabel.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+
+#include <ctype.h>
+#include <err.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#define LBUF 100
+static char lbuf[LBUF];
+
+/*
+ * 14-Dec-89  Robert Baron (rvb) at Carnegie-Mellon University
+ *	Copyright (c) 1989	Robert. V. Baron
+ *	Created.
+ */
+
+char *disk = "/dev/rwd0d";
+
+struct disklabel disklabel;		/* disk parameters */
+
+int cylinders, sectors, heads, cylindersectors, disksectors;
+
+struct mboot {
+	unsigned char padding[2]; /* force the longs to be long alligned */
+	unsigned char bootinst[DOSPARTOFF];
+	struct	dos_partition parts[4];
+	unsigned short int	signature;
+};
+struct mboot mboot;
+
+#define ACTIVE 0x80
+#define BOOT_MAGIC 0xAA55
+
+int dos_cylinders;
+int dos_heads;
+int dos_sectors;
+int dos_cylindersectors;
+
+#define DOSSECT(s,c)	(((s) & 0x3f) | (((c) >> 2) & 0xc0))
+#define DOSCYL(c)	((c) & 0xff)
+int partition = -1;
+
+int a_flag;		/* set active partition */
+int i_flag;		/* replace partition data */
+int u_flag;		/* update partition data */
+
+unsigned char bootcode[] = {
+0x33, 0xc0, 0xfa, 0x8e, 0xd0, 0xbc, 0x00, 0x7c, 0x8e, 0xc0, 0x8e, 0xd8, 0xfb, 0x8b, 0xf4, 0xbf,
+0x00, 0x06, 0xb9, 0x00, 0x02, 0xfc, 0xf3, 0xa4, 0xea, 0x1d, 0x06, 0x00, 0x00, 0xb0, 0x04, 0xbe,
+0xbe, 0x07, 0x80, 0x3c, 0x80, 0x74, 0x0c, 0x83, 0xc6, 0x10, 0xfe, 0xc8, 0x75, 0xf4, 0xbe, 0xbd,
+0x06, 0xeb, 0x43, 0x8b, 0xfe, 0x8b, 0x14, 0x8b, 0x4c, 0x02, 0x83, 0xc6, 0x10, 0xfe, 0xc8, 0x74,
+0x0a, 0x80, 0x3c, 0x80, 0x75, 0xf4, 0xbe, 0xbd, 0x06, 0xeb, 0x2b, 0xbd, 0x05, 0x00, 0xbb, 0x00,
+0x7c, 0xb8, 0x01, 0x02, 0xcd, 0x13, 0x73, 0x0c, 0x33, 0xc0, 0xcd, 0x13, 0x4d, 0x75, 0xef, 0xbe,
+0x9e, 0x06, 0xeb, 0x12, 0x81, 0x3e, 0xfe, 0x7d, 0x55, 0xaa, 0x75, 0x07, 0x8b, 0xf7, 0xea, 0x00,
+0x7c, 0x00, 0x00, 0xbe, 0x85, 0x06, 0x2e, 0xac, 0x0a, 0xc0, 0x74, 0x06, 0xb4, 0x0e, 0xcd, 0x10,
+0xeb, 0xf4, 0xfb, 0xeb, 0xfe,
+'M', 'i', 's', 's', 'i', 'n', 'g', ' ',
+	'o', 'p', 'e', 'r', 'a', 't', 'i', 'n', 'g', ' ', 's', 'y', 's', 't', 'e', 'm', 0,
+'E', 'r', 'r', 'o', 'r', ' ', 'l', 'o', 'a', 'd', 'i', 'n', 'g', ' ',
+	'o', 'p', 'e', 'r', 'a', 't', 'i', 'n', 'g', ' ', 's', 'y', 's', 't', 'e', 'm', 0,
+'I', 'n', 'v', 'a', 'l', 'i', 'd', ' ',
+	'p', 'a', 'r', 't', 'i', 't', 'i', 'o', 'n', ' ', 't', 'a', 'b', 'l', 'e', 0,
+'A', 'u', 't', 'h', 'o', 'r', ' ', '-', ' ',
+	'S', 'i', 'e', 'g', 'm', 'a', 'r', ' ', 'S', 'c', 'h', 'm', 'i', 'd', 't', 0,0,0,
+
+  0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
+  0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
+  0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
+  0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
+  0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
+  0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
+  0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
+  0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
+  0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
+  0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
+  0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
+  0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
+  0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0
+};
+
+struct part_type {
+	int type;
+	char *name;
+} part_types[] = {
+	{0x00, "unused"},
+	{0x01, "Primary DOS with 12 bit FAT"},
+	{0x02, "XENIX / filesystem"},
+	{0x03, "XENIX /usr filesystem"},
+	{0x04, "Primary DOS with 16 bit FAT"},
+	{0x05, "Extended DOS"},
+	{0x06, "Primary 'big' DOS (> 32MB)"},
+	{0x07, "OS/2 HPFS, QNX or Advanced UNIX"},
+	{0x08, "AIX filesystem"},
+	{0x09, "AIX boot partition or Coherent"},
+	{0x0A, "OS/2 Boot Manager or OPUS"},
+	{0x10, "OPUS"},
+	{0x40, "VENIX 286"},
+	{0x50, "DM"},
+	{0x51, "DM"},
+	{0x52, "CP/M or Microport SysV/AT"},
+	{0x56, "GB"},
+	{0x61, "Speed"},
+	{0x63, "ISC UNIX, other System V/386, GNU HURD or Mach"},
+	{0x64, "Novell Netware 2.xx"},
+	{0x65, "Novell Netware 3.xx"},
+	{0x75, "PCIX"},
+	{0x80, "Minix 1.1 ... 1.4a"},
+	{0x81, "Minix 1.4b ... 1.5.10"},
+	{0x82, "Linux swap"},
+	{0x83, "Linux filesystem"},
+	{0x93, "Amoeba filesystem"},
+	{0x94, "Amoeba bad block table"},
+	{0xA5, "NetBSD or 386BSD"},
+	{0xB7, "BSDI BSD/386 filesystem"},
+	{0xB8, "BSDI BSD/386 swap"},
+	{0xDB, "Concurrent CPM or C.DOS or CTOS"},
+	{0xE1, "Speed"},
+	{0xE3, "Speed"},
+	{0xE4, "Speed"},
+	{0xF1, "Speed"},
+	{0xF2, "DOS 3.3+ Secondary"},
+	{0xF4, "Speed"},
+	{0xFF, "BBT (Bad Blocks Table)"},
+};
+
+void	usage __P((void));
+void	print_s0 __P((int));
+void	print_part __P((int));
+void	init_sector0 __P((int));
+void	intuit_translated_geometry __P((void));
+int	try_heads __P((quad_t, quad_t, quad_t, quad_t, quad_t, quad_t, quad_t,
+		       quad_t));
+int	try_sectors __P((quad_t, quad_t, quad_t, quad_t, quad_t));
+void	change_part __P((int));
+void	print_params __P((void));
+void	change_active __P((int));
+void	get_params_to_use __P((void));
+void	dos __P((int, unsigned char *, unsigned char *, unsigned char *));
+int	open_disk __P((int));
+int	read_disk __P((int, void *));
+int	write_disk __P((int, void *));
+int	get_params __P((void));
+int	read_s0 __P((void));
+int	write_s0 __P((void));
+int	yesno __P((char *));
+void	decimal __P((char *, int *));
+int	type_match __P((const void *, const void *));
+char	*get_type __P((int));
+
+int
+main(argc, argv)
+	int argc;
+	char *argv[];
+{
+	int ch;
+	int part;
+
+	a_flag = i_flag = u_flag = 0;
+	while ((ch = getopt(argc, argv, "0123aiu")) != -1)
+		switch (ch) {
+		case '0':
+			partition = 0;
+			break;
+		case '1':
+			partition = 1;
+			break;
+		case '2':
+			partition = 2;
+			break;
+		case '3':
+			partition = 3;
+			break;
+		case 'a':
+			a_flag = 1;
+			break;
+		case 'i':
+			i_flag = 1;
+		case 'u':
+			u_flag = 1;
+			break;
+		default:
+			usage();
+		}
+	argc -= optind;
+	argv += optind;
+
+	if (argc > 0)
+		disk = argv[0];
+
+	if (open_disk(a_flag || i_flag || u_flag) < 0)
+		exit(1);
+
+	if (read_s0())
+		init_sector0(1);
+
+	intuit_translated_geometry();
+
+	printf("******* Working on device %s *******\n", disk);
+	if (u_flag)
+		get_params_to_use();
+	else
+		print_params();
+
+	printf("Warning: BIOS sector numbering starts with sector 1\n");
+	printf("Information from DOS bootblock is:\n");
+	if (partition == -1) {
+		for (part = 0; part < NDOSPART; part++)
+			change_part(part);
+	} else
+		change_part(partition);
+
+	if (u_flag || a_flag)
+		change_active(partition);
+
+	if (u_flag || a_flag) {
+		printf("\nWe haven't changed the partition table yet.  ");
+		printf("This is your last chance.\n");
+		print_s0(-1);
+		if (yesno("Should we write new partition table?"))
+			write_s0();
+	}
+
+	exit(0);
+}
+
+void
+usage()
+{
+
+	(void)fprintf(stderr, "usage: fdisk [-aiu] [-0|-1|-2|-3] [device]\n");
+	exit(1);
+}
+
+void
+print_s0(which)
+	int which;
+{
+	int part;
+
+	print_params();
+	printf("Information from DOS bootblock is:\n");
+	if (which == -1) {
+		for (part = 0; part < NDOSPART; part++)
+			printf("%d: ", part), print_part(part);
+	} else
+		print_part(which);
+}
+
+static struct dos_partition mtpart = { 0 };
+
+void
+print_part(part)
+	int part;
+{
+	struct dos_partition *partp;
+
+	partp = &mboot.parts[part];
+	if (!memcmp(partp, &mtpart, sizeof(struct dos_partition))) {
+		printf("<UNUSED>\n");
+		return;
+	}
+	printf("sysid %d (%s)\n", partp->dp_typ, get_type(partp->dp_typ));
+	printf("    start %d, size %d (%d MB), flag %x\n",
+	    partp->dp_start, partp->dp_size,
+	    partp->dp_size * 512 / (1024 * 1024), partp->dp_flag);
+	printf("\tbeg: cylinder %4d, head %3d, sector %2d\n",
+	    DPCYL(partp->dp_scyl, partp->dp_ssect),
+	    partp->dp_shd, DPSECT(partp->dp_ssect));
+	printf("\tend: cylinder %4d, head %3d, sector %2d\n",
+	    DPCYL(partp->dp_ecyl, partp->dp_esect),
+	    partp->dp_ehd, DPSECT(partp->dp_esect));
+}
+
+void
+init_sector0(start)
+	int start;
+{
+	struct dos_partition *partp;
+
+	memcpy(mboot.bootinst, bootcode, sizeof(bootcode));
+	mboot.signature = BOOT_MAGIC;
+
+	partp = &mboot.parts[3];
+	partp->dp_typ = DOSPTYP_386BSD;
+	partp->dp_flag = ACTIVE;
+	partp->dp_start = start;
+	partp->dp_size = disksectors - start;
+
+	dos(partp->dp_start,
+	    &partp->dp_scyl, &partp->dp_shd, &partp->dp_ssect);
+	dos(partp->dp_start + partp->dp_size - 1,
+	    &partp->dp_ecyl, &partp->dp_ehd, &partp->dp_esect);
+}
+
+/* Prerequisite: the disklabel parameters and master boot record must
+ *		 have been read (i.e. dos_* and mboot are meaningful).
+ * Specification: modifies dos_cylinders, dos_heads, dos_sectors, and
+ *		  dos_cylindersectors to be consistent with what the
+ *		  partition table is using, if we can find a geometry
+ *		  which is consistent with all partition table entries.
+ *		  We may get the number of cylinders slightly wrong (in
+ *		  the conservative direction).  The idea is to be able
+ *		  to create a NetBSD partition on a disk we don't know
+ *		  the translated geometry of.
+ * This whole routine should be replaced with a kernel interface to get
+ * the BIOS geometry (which in turn requires modifications to the i386
+ * boot loader to pass in the BIOS geometry for each disk). */
+void
+intuit_translated_geometry()
+{
+	int cylinders = -1, heads = -1, sectors = -1, i, j;
+	int c1, h1, s1, c2, h2, s2;
+	long a1, a2;
+	quad_t num, denom;
+
+	/* Try to deduce the number of heads from two different mappings. */
+	for (i = 0; i < NDOSPART * 2; i++) {
+		if (get_mapping(i, &c1, &h1, &s1, &a1) < 0)
+			continue;
+		for (j = 0; j < 8; j++) {
+			if (get_mapping(j, &c2, &h2, &s2, &a2) < 0)
+				continue;
+			num = (quad_t)h1*(a2-s2) - h2*(a1-s1);
+			denom = (quad_t)c2*(a1-s1) - c1*(a2-s2);
+			if (denom != 0 && num % denom == 0) {
+				heads = num / denom;
+				break;
+			}
+		}
+		if (heads != -1)	
+			break;
+	}
+
+	if (heads == -1)
+		return;
+
+	/* Now figure out the number of sectors from a single mapping. */
+	for (i = 0; i < NDOSPART * 2; i++) {
+		if (get_mapping(i, &c1, &h1, &s1, &a1) < 0)
+			continue;
+		num = a1 - s1;
+		denom = c1 * heads + h1;
+		if (denom != 0 && num % denom == 0) {
+			sectors = num / denom;
+			break;
+		}
+	}
+
+	if (sectors == -1)
+		return;
+
+	/* Estimate the number of cylinders. */
+	cylinders = dos_cylinders * dos_cylindersectors / heads / sectors;
+
+	/* Now verify consistency with each of the partition table entries.
+	 * Be willing to shove cylinders up a little bit to make things work,
+	 * but translation mismatches are fatal. */
+	for (i = 0; i < NDOSPART * 2; i++) {
+		if (get_mapping(i, &c1, &h1, &s1, &a1) < 0)
+			continue;
+		if (sectors * (c1 * heads + h1) + s1 != a1)
+			return;
+		if (c1 >= cylinders)
+			cylinders = c1 + 1;
+	}
+
+	/* Everything checks out.  Reset the geometry to use for further
+	 * calculations. */
+	dos_cylinders = cylinders;
+	dos_heads = heads;
+	dos_sectors = sectors;
+	dos_cylindersectors = heads * sectors;
+}
+
+/* For the purposes of intuit_translated_geometry(), treat the partition
+ * table as a list of eight mapping between (cylinder, head, sector)
+ * triplets and absolute sectors.  Get the relevant geometry triplet and
+ * absolute sectors for a given entry, or return -1 if it isn't present.
+ * Note: for simplicity, the returned sector is 0-based. */
+int
+get_mapping(i, cylinder, head, sector, absolute)
+	int i, *cylinder, *head, *sector;
+	long *absolute;
+{
+	struct dos_partition *part = &mboot.parts[i / 2];
+
+	if (part->dp_typ == 0)
+		return -1;
+	if (i % 2 == 0) {
+		*cylinder = DPCYL(part->dp_scyl, part->dp_ssect);
+		*head = part->dp_shd;
+		*sector = DPSECT(part->dp_ssect) - 1;
+		*absolute = part->dp_start;
+	} else {
+		*cylinder = DPCYL(part->dp_ecyl, part->dp_esect);
+		*head = part->dp_ehd;
+		*sector = DPSECT(part->dp_esect) - 1;
+		*absolute = part->dp_start + part->dp_size - 1;
+	}
+	return 0;
+}
+
+void
+change_part(part)
+	int part;
+{
+	struct dos_partition *partp;
+
+	partp = &mboot.parts[part];
+
+	printf("The data for partition %d is:\n", part);
+	print_part(part);
+
+	if (!u_flag || !yesno("Do you want to change it?"))
+		return;
+
+	if (i_flag) {
+		memset(partp, 0, sizeof(*partp));
+		if (part == 3) {
+			init_sector0(1);
+			printf("\nThe static data for the DOS partition 3 has been reinitialized to:\n");
+			print_part(part);
+		}
+	}
+
+	do {
+		{
+			int sysid, start, size;
+
+			sysid = partp->dp_typ,
+			start = partp->dp_start,
+			size = partp->dp_size;
+			decimal("sysid", &sysid);
+			decimal("start", &start);
+			decimal("size", &size);
+			partp->dp_typ = sysid;
+			partp->dp_start = start;
+			partp->dp_size = size;
+		}
+
+		if (yesno("Explicitly specify beg/end address?")) {
+			int tsector, tcylinder, thead;
+
+			tcylinder = DPCYL(partp->dp_scyl, partp->dp_ssect);
+			thead = partp->dp_shd;
+			tsector = DPSECT(partp->dp_ssect);
+			decimal("beginning cylinder", &tcylinder);
+			decimal("beginning head", &thead);
+			decimal("beginning sector", &tsector);
+			partp->dp_scyl = DOSCYL(tcylinder);
+			partp->dp_shd = thead;
+			partp->dp_ssect = DOSSECT(tsector, tcylinder);
+
+			tcylinder = DPCYL(partp->dp_ecyl, partp->dp_esect);
+			thead = partp->dp_ehd;
+			tsector = DPSECT(partp->dp_esect);
+			decimal("ending cylinder", &tcylinder);
+			decimal("ending head", &thead);
+			decimal("ending sector", &tsector);
+			partp->dp_ecyl = DOSCYL(tcylinder);
+			partp->dp_ehd = thead;
+			partp->dp_esect = DOSSECT(tsector, tcylinder);
+		} else {
+			dos(partp->dp_start,
+			    &partp->dp_scyl, &partp->dp_shd, &partp->dp_ssect);
+			dos(partp->dp_start + partp->dp_size - 1,
+			    &partp->dp_ecyl, &partp->dp_ehd, &partp->dp_esect);
+		}
+
+		print_part(part);
+	} while (!yesno("Is this entry okay?"));
+}
+
+void
+print_params()
+{
+
+	printf("parameters extracted from in-core disklabel are:\n");
+	printf("cylinders=%d heads=%d sectors/track=%d (%d sectors/cylinder)\n\n",
+	    cylinders, heads, sectors, cylindersectors);
+	if (dos_sectors > 63 || dos_cylinders > 1023 || dos_heads > 255)
+		printf("Figures below won't work with BIOS for partitions not in cylinder 1\n");
+	printf("parameters to be used for BIOS calculations are:\n");
+	printf("cylinders=%d heads=%d sectors/track=%d (%d sectors/cylinder)\n\n",
+	    dos_cylinders, dos_heads, dos_sectors, dos_cylindersectors);
+}
+
+void
+change_active(which)
+	int which;
+{
+	struct dos_partition *partp;
+	int part;
+	int active = 3;
+
+	partp = &mboot.parts[0];
+
+	if (a_flag && which != -1)
+		active = which;
+	else {
+		for (part = 0; part < NDOSPART; part++)
+			if (partp[part].dp_flag & ACTIVE)
+				active = part;
+	}
+	if (yesno("Do you want to change the active partition?")) {
+		do {
+			decimal("active partition", &active);
+		} while (!yesno("Are you happy with this choice?"));
+	}
+	for (part = 0; part < NDOSPART; part++)
+		partp[part].dp_flag &= ~ACTIVE;
+	partp[active].dp_flag |= ACTIVE;
+}
+
+void
+get_params_to_use()
+{
+
+	print_params();
+	if (yesno("Do you want to change our idea of what BIOS thinks?")) {
+		do {
+			decimal("BIOS's idea of #cylinders", &dos_cylinders);
+			decimal("BIOS's idea of #heads", &dos_heads);
+			decimal("BIOS's idea of #sectors", &dos_sectors);
+			dos_cylindersectors = dos_heads * dos_sectors;
+			print_params();
+		} while (!yesno("Are you happy with this choice?"));
+	}
+}
+
+/***********************************************\
+* Change real numbers into strange dos numbers	*
+\***********************************************/
+void
+dos(sector, cylinderp, headp, sectorp)
+	int sector;
+	unsigned char *cylinderp, *headp, *sectorp;
+{
+	int cylinder, head;
+
+	cylinder = sector / dos_cylindersectors;
+	sector -= cylinder * dos_cylindersectors;
+
+	head = sector / dos_sectors;
+	sector -= head * dos_sectors;
+
+	*cylinderp = DOSCYL(cylinder);
+	*headp = head;
+	*sectorp = DOSSECT(sector + 1, cylinder);
+}
+
+int fd;
+
+int
+open_disk(u_flag)
+	int u_flag;
+{
+	struct stat st;
+
+	if ((fd = open(disk, u_flag ? O_RDWR : O_RDONLY)) == -1) {
+		warn("%s", disk);
+		return (-1);
+	}
+	if (fstat(fd, &st) == -1) {
+		close(fd);
+		warn("%s", disk);
+		return (-1);
+	}
+	if (!S_ISCHR(st.st_mode) && !S_ISREG(st.st_mode)) {
+		close(fd);
+		warnx("%s is not a character device or regular file", disk);
+		return (-1);
+	}
+	if (get_params() == -1) {
+		close(fd);
+		return (-1);
+	}
+	return (0);
+}
+
+int
+read_disk(sector, buf)
+	int sector;
+	void *buf;
+{
+
+	if (lseek(fd, (off_t)(sector * 512), 0) == -1)
+		return (-1);
+	return (read(fd, buf, 512));
+}
+
+int
+write_disk(sector, buf)
+	int sector;
+	void *buf;
+{
+
+	if (lseek(fd, (off_t)(sector * 512), 0) == -1)
+		return (-1);
+	return (write(fd, buf, 512));
+}
+
+int
+get_params()
+{
+
+	if (ioctl(fd, DIOCGDINFO, &disklabel) == -1) {
+		warn("DIOCGDINFO");
+		return (-1);
+	}
+
+	dos_cylinders = cylinders = disklabel.d_ncylinders;
+	dos_heads = heads = disklabel.d_ntracks;
+	dos_sectors = sectors = disklabel.d_nsectors;
+	dos_cylindersectors = cylindersectors = heads * sectors;
+	disksectors = cylinders * heads * sectors;
+
+	return (0);
+}
+
+int
+read_s0()
+{
+
+	if (read_disk(0, mboot.bootinst) == -1) {
+		warn("can't read fdisk partition table");
+		return (-1);
+	}
+	if (mboot.signature != BOOT_MAGIC) {
+		warn("invalid fdisk partition table found");
+		/* So should we initialize things? */
+		return (-1);
+	}
+	return (0);
+}
+
+int
+write_s0()
+{
+	int flag;
+
+	/*
+	 * write enable label sector before write (if necessary),
+	 * disable after writing.
+	 * needed if the disklabel protected area also protects
+	 * sector 0. (e.g. empty disk)
+	 */
+	flag = 1;
+	if (ioctl(fd, DIOCWLABEL, &flag) < 0)
+		warn("DIOCWLABEL");
+	if (write_disk(0, mboot.bootinst) == -1) {
+		warn("can't write fdisk partition table");
+		return -1;
+	}
+	flag = 0;
+	if (ioctl(fd, DIOCWLABEL, &flag) < 0)
+		warn("DIOCWLABEL");
+}
+
+int
+yesno(str)
+	char *str;
+{
+	int ch, first;
+
+	printf("%s [n] ", str);
+
+	first = ch = getchar();
+	while (ch != '\n' && ch != EOF)
+		ch = getchar();
+	return (first == 'y' || first == 'Y');
+}
+
+void
+decimal(str, num)
+	char *str;
+	int *num;
+{
+	int acc = 0;
+	char *cp;
+
+	for (;; printf("%s is not a valid decimal number.\n", lbuf)) {
+		printf("Supply a decimal value for \"%s\" [%d] ", str, *num);
+
+		fgets(lbuf, LBUF, stdin);
+		lbuf[strlen(lbuf)-1] = '\0';
+		cp = lbuf;
+
+		cp += strspn(cp, " \t");
+		if (*cp == '\0')
+			return;
+
+		if (!isdigit(*cp))
+			continue;
+		acc = strtol(lbuf, &cp, 10);
+
+		cp += strspn(cp, " \t");
+		if (*cp != '\0')
+			continue;
+
+		*num = acc;
+		return;
+	}
+
+}
+
+int
+type_match(key, item)
+	const void *key, *item;
+{
+	const int *typep = key;
+	const struct part_type *ptr = item;
+
+	if (*typep < ptr->type)
+		return (-1);
+	if (*typep > ptr->type)
+		return (1);
+	return (0);
+}
+
+char *
+get_type(type)
+	int type;
+{
+	struct part_type *ptr;
+
+	ptr = bsearch(&type, part_types,
+	    sizeof(part_types) / sizeof(struct part_type),
+	    sizeof(struct part_type), type_match);
+	if (ptr == 0)
+		return ("unknown");
+	else
+		return (ptr->name);
+}