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Diffstat (limited to 'sys/boot/common/disk.h')
| -rw-r--r-- | sys/boot/common/disk.h | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/sys/boot/common/disk.h b/sys/boot/common/disk.h new file mode 100644 index 0000000..0fc7e91 --- /dev/null +++ b/sys/boot/common/disk.h @@ -0,0 +1,99 @@ +/*- + * 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. We assume that all disk addresses + * are 512 byte block offsets from the start of the disk. 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..7) + * + * 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 slice_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. + */ + +#define DISK_SECSIZE 512 + +struct disk_devdesc +{ + struct devsw *d_dev; + int d_type; + int d_unit; + void *d_opendata; + int d_slice; + int d_partition; + int d_offset; +}; + +/* + * Parse disk metadata and initialise dev->d_offset. + */ +extern int disk_open(struct disk_devdesc * dev); + +/* + * Print information about slices on a disk. For the size calculations we + * assume a 512 byte sector. + */ +extern void disk_print(struct disk_devdesc *dev, char *prefix, int verbose); |
