usr/src/boot/sys/boot/common/disk.h

   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 = -1
  34  *      d_partition = -1
  35  *
  36  * Whole MBR slice:
  37  *
  38  *      d_slice = MBR slice number (typically 1..4)
  39  *      d_partition = -1
  40  *
  41  * VTOC disklabel partition within an MBR slice:
  42  *
  43  *      d_slice = MBR slice number (typically 1..4)
  44  *      d_partition = disklabel partition (typically 0..19)
  45  *
  46  * BSD disklabel partition within an MBR slice:
  47  *
  48  *      d_slice = MBR slice number (typically 1..4)
  49  *      d_partition = disklabel partition (typically 0..19)
  50  *
  51  * BSD disklabel partition on the true dedicated disk:
  52  *
  53  *      d_slice = -1
  54  *      d_partition = disklabel partition (typically 0..19)
  55  *
  56  * GPT partition:
  57  *
  58  *      d_slice = GPT partition number (typically 1..N)
  59  *      d_partition = 255
  60  *
  61  * For both MBR and GPT, to automatically find the 'best' slice or partition,
  62  * set d_slice to zero. This uses the partition type to decide which partition
  63  * to use according to the following list of preferences:
  64  *
  65  *      Solaris2 (active)
  66  *      Solaris2 (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 struct disk_devdesc {
  88         struct devdesc  dd;             /* Must be first. */
  89         int             d_slice;
  90         int             d_partition;
  91         uint64_t        d_offset;
  92 };
  93
  94 enum disk_ioctl {
  95         IOCTL_GET_BLOCKS,
  96         IOCTL_GET_BLOCK_SIZE
  97 };
  98
  99 /*
 100  * Parse disk metadata and initialise dev->d_offset.
 101  */
 102 extern int disk_open(struct disk_devdesc *, uint64_t, u_int);
 103 extern int disk_close(struct disk_devdesc *);
 104 extern int disk_ioctl(struct disk_devdesc *, u_long, void *);
 105 extern int disk_read(struct disk_devdesc *, void *, uint64_t, u_int);
 106 extern int disk_write(struct disk_devdesc *, void *, uint64_t, u_int);
 107
 108 /*
 109  * Print information about slices on a disk.
 110  */
 111 extern int disk_print(struct disk_devdesc *, char *, int);
 112 extern char* disk_fmtdev(struct disk_devdesc *);
 113 extern int disk_parsedev(struct disk_devdesc *, const char *, const char **);
 114
 115 #endif  /* _DISK_H */