freebsd-skq/stand/common/disk.h
Warner Losh de04d704a9 Use the actual struct devdesc at the start of all *_devdesc structs
The current system is fragile and requires very careful layout of all
*_devdesc structures. It also makes it hard to change the base
devdesc. Take a page from CAM and put the 'header' in all the derived
classes and adjust the code to match.

For OFW, move the iHandle h_handle out of a slot conflicting with
d_opendata. Due to quirks in the alignment rules, this worked.
However changing the code to use d_opendata storage now that it's a
pointer is hard, so just have a separate field for it.

All other cleanups were to make the *_devdesc structures match where
they'd taken some liberties that were none-the-less compatible enough
to work.
2018-03-12 21:39:49 +00:00

115 lines
3.8 KiB
C

/*-
* Copyright (c) 2011 Google, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
/*
* Device descriptor for partitioned disks. To use, set the
* d_slice and d_partition variables as follows:
*
* Whole disk access:
*
* d_slice = -1
* d_partition = -1
*
* Whole MBR slice:
*
* d_slice = MBR slice number (typically 1..4)
* d_partition = -1
*
* BSD disklabel partition within an MBR slice:
*
* d_slice = MBR slice number (typically 1..4)
* d_partition = disklabel partition (typically 0..19)
*
* BSD disklabel partition on the true dedicated disk:
*
* d_slice = -1
* d_partition = disklabel partition (typically 0..19)
*
* GPT partition:
*
* d_slice = GPT partition number (typically 1..N)
* d_partition = 255
*
* For both MBR and GPT, to automatically find the 'best' slice or partition,
* set d_slice to zero. This uses the partition type to decide which partition
* to use according to the following list of preferences:
*
* FreeBSD (active)
* FreeBSD (inactive)
* Linux (active)
* Linux (inactive)
* DOS/Windows (active)
* DOS/Windows (inactive)
*
* Active MBR slices (marked as bootable) are preferred over inactive. GPT
* doesn't have the concept of active/inactive partitions. In both MBR and GPT,
* if there are multiple slices/partitions of a given type, the first one
* is chosen.
*
* The low-level disk device will typically call disk_open() from its open
* method to interpret the disk partition tables according to the rules above.
* This will initialize d_offset to the block offset of the start of the
* selected partition - this offset should be added to the offset passed to
* the device's strategy method.
*/
#ifndef _DISK_H
#define _DISK_H
/* Note: Must match the 'struct devdesc' in stand.h */
struct disk_devdesc {
struct devdesc dd;
int d_slice;
int d_partition;
uint64_t d_offset;
};
enum disk_ioctl {
IOCTL_GET_BLOCKS,
IOCTL_GET_BLOCK_SIZE
};
/*
* Parse disk metadata and initialise dev->d_offset.
*/
extern int disk_open(struct disk_devdesc *, uint64_t, u_int);
extern int disk_close(struct disk_devdesc *);
extern int disk_ioctl(struct disk_devdesc *, u_long, void *);
extern int disk_read(struct disk_devdesc *, void *, uint64_t, u_int);
extern int disk_write(struct disk_devdesc *, void *, uint64_t, u_int);
extern int ptblread(void *, void *, size_t, uint64_t);
/*
* Print information about slices on a disk.
*/
extern int disk_print(struct disk_devdesc *, char *, int);
extern char* disk_fmtdev(struct disk_devdesc *);
extern int disk_parsedev(struct disk_devdesc *, const char *, const char **);
#endif /* _DISK_H */