xref: /freebsd/stand/common/disk.h (revision 123af6ec70016f5556da5972d4d63c7d175c06d3)
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 = -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 
81 #ifndef	_DISK_H
82 #define	_DISK_H
83 
84 struct disk_devdesc {
85 	struct devdesc	dd;		/* Must be first. */
86 	int		d_slice;
87 	int		d_partition;
88 	uint64_t	d_offset;
89 };
90 
91 enum disk_ioctl {
92 	IOCTL_GET_BLOCKS,
93 	IOCTL_GET_BLOCK_SIZE
94 };
95 
96 /*
97  * Parse disk metadata and initialise dev->d_offset.
98  */
99 extern int disk_open(struct disk_devdesc *, uint64_t, u_int);
100 extern int disk_close(struct disk_devdesc *);
101 extern int disk_ioctl(struct disk_devdesc *, u_long, void *);
102 extern int disk_read(struct disk_devdesc *, void *, uint64_t, u_int);
103 extern int disk_write(struct disk_devdesc *, void *, uint64_t, u_int);
104 extern int ptblread(void *, void *, size_t, uint64_t);
105 
106 /*
107  * Print information about slices on a disk.
108  */
109 extern int disk_print(struct disk_devdesc *, char *, int);
110 extern char* disk_fmtdev(struct disk_devdesc *);
111 extern int disk_parsedev(struct disk_devdesc *, const char *, const char **);
112 
113 #endif	/* _DISK_H */
114