1/*-
2 * Copyright (c) 2011 Google, Inc.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27/*
28 * Device descriptor for partitioned disks. To use, set the
29 * d_slice and d_partition variables as follows:
30 *
31 * Whole disk access:
32 *
33 * 	d_slice = D_SLICENONE
34 * 	d_partition = <doesn't matter>
35 *
36 * Whole MBR slice:
37 *
38 * 	d_slice = MBR slice number (typically 1..4)
39 * 	d_partition = D_PARTNONE
40 *
41 * BSD disklabel partition within an MBR slice:
42 *
43 * 	d_slice = MBR slice number (typically 1..4)
44 * 	d_partition = disklabel partition (typically 0..19 or D_PARTWILD)
45 *
46 * BSD disklabel partition on the true dedicated disk:
47 *
48 * 	d_slice = D_SLICENONE
49 * 	d_partition = disklabel partition (typically 0..19 or D_PARTWILD)
50 *
51 * GPT partition:
52 *
53 * 	d_slice = GPT partition number (typically 1..N)
54 * 	d_partition = D_PARTISGPT
55 *
56 * For MBR, setting d_partition to D_PARTWILD will automatically use the first
57 * partition within the slice.
58 *
59 * For both MBR and GPT, to automatically find the 'best' slice and partition,
60 * set d_slice to D_SLICEWILD. This uses the partition type to decide which
61 * partition to use according to the following list of preferences:
62 *
63 * 	FreeBSD (active)
64 * 	FreeBSD (inactive)
65 * 	Linux (active)
66 * 	Linux (inactive)
67 * 	DOS/Windows (active)
68 * 	DOS/Windows (inactive)
69 *
70 * Active MBR slices (marked as bootable) are preferred over inactive. GPT
71 * doesn't have the concept of active/inactive partitions. In both MBR and GPT,
72 * if there are multiple slices/partitions of a given type, the first one
73 * is chosen.
74 *
75 * The low-level disk device will typically call disk_open() from its open
76 * method to interpret the disk partition tables according to the rules above.
77 * This will initialize d_offset to the block offset of the start of the
78 * selected partition - this offset should be added to the offset passed to
79 * the device's strategy method.
80 */
81
82#ifndef	_DISK_H
83#define	_DISK_H
84
85#define	D_SLICENONE	-1
86#define	D_SLICEWILD	 0
87#define	D_PARTNONE	-1
88#define	D_PARTWILD	-2
89#define	D_PARTISGPT	255
90
91struct disk_devdesc {
92	struct devdesc	dd;		/* Must be first. */
93	int		d_slice;
94	int		d_partition;
95	uint64_t	d_offset;
96};
97
98/*
99 * Parse disk metadata and initialise dev->d_offset.
100 */
101extern int disk_open(struct disk_devdesc *, uint64_t, u_int);
102extern int disk_close(struct disk_devdesc *);
103extern int disk_ioctl(struct disk_devdesc *, u_long, void *);
104extern int disk_read(struct disk_devdesc *, void *, uint64_t, u_int);
105extern int disk_write(struct disk_devdesc *, void *, uint64_t, u_int);
106extern int ptblread(void *, void *, size_t, uint64_t);
107
108/*
109 * Print information about slices on a disk.
110 */
111extern int disk_print(struct disk_devdesc *, char *, int);
112extern int disk_parsedev(struct devdesc **, const char *, const char **);
113
114char *disk_fmtdev(struct devdesc *vdev);
115
116#endif	/* _DISK_H */
117