Description of a disk device (logical and physical disks). More...

#include <diskdevs.h>

Data Fields
dev_t	dev
	Device identifier (concatenation of major and minor number).

rtems_disk_device *	phys_dev
	Physical device identifier (equals the `dev` entry if it specifies a physical device).

uint32_t	capabilities
	Driver capabilities.

char *	name
	Disk device name.

unsigned	uses
	Usage counter.

rtems_blkdev_bnum	start
	Start media block number.

rtems_blkdev_bnum	size
	Size of the physical or logical disk in media blocks.

uint32_t	media_block_size
	Media block size in bytes.

uint32_t	block_size
	Block size in bytes.

rtems_blkdev_bnum	block_count
	Block count.

uint32_t	media_blocks_per_block
	Media blocks per device blocks.

int	block_to_media_block_shift
	Block to media block shift.

size_t	bds_per_group
	Buffer descriptors per group count.

rtems_block_device_ioctl	ioctl
	IO control handler for this disk.

void *	driver_data
	Private data for the disk driver.

bool	deleted
	Indicates that this disk should be deleted as soon as the last user releases this disk.

rtems_blkdev_stats	stats
	Device statistics for this disk.

rtems_blkdev_read_ahead	read_ahead
	Read-ahead control for this disk.

Detailed Description

Description of a disk device (logical and physical disks).

An array of pointer tables to rtems_disk_device structures is maintained. The first table will be indexed by the major number and the second table will be indexed by the minor number. This allows quick lookup using a data structure of moderated size.

Field Documentation

◆ bds_per_group

size_t rtems_disk_device::bds_per_group

Buffer descriptors per group count.

See also: rtems_bdbuf_set_block_size().

◆ block_count

rtems_blkdev_bnum rtems_disk_device::block_count

Block count.

See also: rtems_bdbuf_set_block_size().

◆ block_size

uint32_t rtems_disk_device::block_size

Block size in bytes.

This is the minimum transfer unit. It may be a multiple of the media block size. It must be positive.

See also: rtems_bdbuf_set_block_size().

◆ block_to_media_block_shift

int rtems_disk_device::block_to_media_block_shift

Block to media block shift.

In case this value is non-negative the media block of a block can be calculated as media block = block << block_to_media_block_shift, otherwise a 64-bit operation will be used.

See also: rtems_bdbuf_set_block_size().

◆ media_block_size

uint32_t rtems_disk_device::media_block_size

Media block size in bytes.

This is the media transfer unit the hardware defaults to.

◆ media_blocks_per_block

uint32_t rtems_disk_device::media_blocks_per_block

Media blocks per device blocks.

See also: rtems_bdbuf_set_block_size().

◆ start

rtems_blkdev_bnum rtems_disk_device::start

Start media block number.

Equals zero for physical devices. It is a media block offset to the related physical device for logical device.

◆ uses

unsigned rtems_disk_device::uses

Usage counter.

Devices cannot be deleted if they are in use.

The documentation for this struct was generated from the following file:

cpukit/include/rtems/diskdevs.h

Data Fields