disk.h revision 273117 
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 * $FreeBSD: stable/10/sys/boot/common/disk.h 273117 2014-10-15 04:34:07Z ae $
27 */
28
29/*
30 * Device descriptor for partitioned disks. To use, set the
31 * d_slice and d_partition variables as follows:
32 *
33 * Whole disk access:
34 *
35 * 	d_slice = -1
36 * 	d_partition = -1
37 *
38 * Whole MBR slice:
39 *
40 * 	d_slice = MBR slice number (typically 1..4)
41 * 	d_partition = -1
42 *
43 * BSD disklabel partition within an MBR slice:
44 *
45 * 	d_slice = MBR slice number (typically 1..4)
46 * 	d_partition = disklabel partition (typically 0..19)
47 *
48 * BSD disklabel partition on the true dedicated disk:
49 *
50 * 	d_slice = -1
51 * 	d_partition = disklabel partition (typically 0..19)
52 *
53 * GPT partition:
54 *
55 * 	d_slice = GPT partition number (typically 1..N)
56 * 	d_partition = 255
57 *
58 * For both MBR and GPT, to automatically find the 'best' slice or partition,
59 * set d_slice to zero. This uses the partition type to decide which partition
60 * to use according to the following list of preferences:
61 *
62 * 	FreeBSD (active)
63 * 	FreeBSD (inactive)
64 * 	Linux (active)
65 * 	Linux (inactive)
66 * 	DOS/Windows (active)
67 * 	DOS/Windows (inactive)
68 *
69 * Active MBR slices (marked as bootable) are preferred over inactive. GPT
70 * doesn't have the concept of active/inactive partitions. In both MBR and GPT,
71 * if there are multiple slices/partitions of a given type, the first one
72 * is chosen.
73 *
74 * The low-level disk device will typically call disk_open() from its open
75 * method to interpret the disk partition tables according to the rules above.
76 * This will initialize d_offset to the block offset of the start of the
77 * selected partition - this offset should be added to the offset passed to
78 * the device's strategy method.
79 */
80
81struct disk_devdesc
82{
83	struct devsw	*d_dev;
84	int		d_type;
85	int		d_unit;
86	void		*d_opendata;
87	int		d_slice;
88	int		d_partition;
89	off_t		d_offset;
90};
91
92/*
93 * Parse disk metadata and initialise dev->d_offset.
94 */
95extern int disk_open(struct disk_devdesc *dev, off_t mediasize,
96    u_int sectorsize, u_int flags);
97#define	DISK_F_NOCACHE	0x0001		/* Do not use metadata caching */
98extern int disk_close(struct disk_devdesc *dev);
99extern void disk_cleanup(const struct devsw *d_dev);
100
101/*
102 * Print information about slices on a disk.
103 */
104extern void disk_print(struct disk_devdesc *dev, char *prefix, int verbose);
105extern char* disk_fmtdev(struct disk_devdesc *dev);
106extern int disk_parsedev(struct disk_devdesc *dev, const char *devspec,
107    const char **path);
108
109