stand/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 = 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
  91 struct 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  */
 101 extern int disk_open(struct disk_devdesc *, uint64_t, u_int);
 102 extern int disk_close(struct disk_devdesc *);
 103 extern int disk_ioctl(struct disk_devdesc *, u_long, void *);
 104 extern int disk_read(struct disk_devdesc *, void *, uint64_t, u_int);
 105 extern int disk_write(struct disk_devdesc *, void *, uint64_t, u_int);
 106 extern int ptblread(void *, void *, size_t, uint64_t);
 107
 108 /*
 109  * Print information about slices on a disk.
 110  */
 111 extern int disk_print(struct disk_devdesc *, char *, int);
 112 extern int disk_parsedev(struct devdesc **, const char *, const char **);
 113
 114 char *disk_fmtdev(struct devdesc *vdev);
 115
 116 #endif  /* _DISK_H */