xref: /freebsd/stand/common/disk.h (revision d6eb98610fa65663bf0df4574b7cb2c5c4ffda71)
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  * $FreeBSD$
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 = D_SLICENONE
36  * 	d_partition = <doesn't matter>
37  *
38  * Whole MBR slice:
39  *
40  * 	d_slice = MBR slice number (typically 1..4)
41  * 	d_partition = D_PARTNONE
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 or D_PARTWILD)
47  *
48  * BSD disklabel partition on the true dedicated disk:
49  *
50  * 	d_slice = D_SLICENONE
51  * 	d_partition = disklabel partition (typically 0..19 or D_PARTWILD)
52  *
53  * GPT partition:
54  *
55  * 	d_slice = GPT partition number (typically 1..N)
56  * 	d_partition = D_PARTISGPT
57  *
58  * For MBR, setting d_partition to D_PARTWILD will automatically use the first
59  * partition within the slice.
60  *
61  * For both MBR and GPT, to automatically find the 'best' slice and partition,
62  * set d_slice to D_SLICEWILD. This uses the partition type to decide which
63  * partition to use according to the following list of preferences:
64  *
65  * 	FreeBSD (active)
66  * 	FreeBSD (inactive)
67  * 	Linux (active)
68  * 	Linux (inactive)
69  * 	DOS/Windows (active)
70  * 	DOS/Windows (inactive)
71  *
72  * Active MBR slices (marked as bootable) are preferred over inactive. GPT
73  * doesn't have the concept of active/inactive partitions. In both MBR and GPT,
74  * if there are multiple slices/partitions of a given type, the first one
75  * is chosen.
76  *
77  * The low-level disk device will typically call disk_open() from its open
78  * method to interpret the disk partition tables according to the rules above.
79  * This will initialize d_offset to the block offset of the start of the
80  * selected partition - this offset should be added to the offset passed to
81  * the device's strategy method.
82  */
83 
84 #ifndef	_DISK_H
85 #define	_DISK_H
86 
87 #define	D_SLICENONE	-1
88 #define	D_SLICEWILD	 0
89 #define	D_PARTNONE	-1
90 #define	D_PARTWILD	-2
91 #define	D_PARTISGPT	255
92 
93 struct disk_devdesc {
94 	struct devdesc	dd;		/* Must be first. */
95 	int		d_slice;
96 	int		d_partition;
97 	uint64_t	d_offset;
98 };
99 
100 enum disk_ioctl {
101 	IOCTL_GET_BLOCKS,
102 	IOCTL_GET_BLOCK_SIZE
103 };
104 
105 /*
106  * Parse disk metadata and initialise dev->d_offset.
107  */
108 extern int disk_open(struct disk_devdesc *, uint64_t, u_int);
109 extern int disk_close(struct disk_devdesc *);
110 extern int disk_ioctl(struct disk_devdesc *, u_long, void *);
111 extern int disk_read(struct disk_devdesc *, void *, uint64_t, u_int);
112 extern int disk_write(struct disk_devdesc *, void *, uint64_t, u_int);
113 extern int ptblread(void *, void *, size_t, uint64_t);
114 
115 /*
116  * Print information about slices on a disk.
117  */
118 extern int disk_print(struct disk_devdesc *, char *, int);
119 extern char* disk_fmtdev(struct disk_devdesc *);
120 extern int disk_parsedev(struct disk_devdesc *, const char *, const char **);
121 
122 #endif	/* _DISK_H */
123