RAM Disk Device

Files
file	ramdisk-config.c
	RAM disk block device implementation.
file	ramdisk-driver.c
	RAM disk block device implementation.
file	ramdisk-init.c
	RAM disk block device implementation.
file	ramdisk-register.c
	RAM disk block device implementation.

Data Structures
struct	rtems_ramdisk_config
	RAM disk configuration table entry. More...
struct	ramdisk
	RAM disk descriptor. More...

Static Configuration
typedef struct rtems_ramdisk_config	rtems_ramdisk_config
	RAM disk configuration table entry.
rtems_ramdisk_config	rtems_ramdisk_configuration []
	External reference to the RAM disk configuration table describing each RAM disk in the system.
size_t	rtems_ramdisk_configuration_size
	External reference the size of the RAM disk configuration table rtems_ramdisk_configuration.
rtems_device_driver	ramdisk_initialize (rtems_device_major_number major, rtems_device_minor_number minor, void *arg)
	RAM disk driver initialization entry point.
#define	RAMDISK_DRIVER_TABLE_ENTRY
#define	RAMDISK_DEVICE_BASE_NAME   "/dev/rd"

Runtime Configuration
typedef struct ramdisk	ramdisk
	RAM disk descriptor.
int	ramdisk_ioctl (rtems_disk_device *dd, uint32_t req, void *argp)
ramdisk *	ramdisk_allocate (void *area_begin, uint32_t media_block_size, rtems_blkdev_bnum media_block_count, bool trace)
	Allocates and initializes a RAM disk descriptor.
void	ramdisk_free (ramdisk *rd)
rtems_status_code	ramdisk_register (uint32_t media_block_size, rtems_blkdev_bnum media_block_count, bool trace, const char *disk)
	Allocates, initializes and registers a RAM disk.

Detailed Description

Macro Definition Documentation

RAMDISK_DRIVER_TABLE_ENTRY

#define RAMDISK_DRIVER_TABLE_ENTRY

Value:

  { \
    ramdisk_initialize, \
    NULL, NULL, NULL, NULL, NULL \
  }

RAM disk driver table entry.

Function Documentation

ramdisk_allocate()

ramdisk * ramdisk_allocate	(	void *	area_begin,
		uint32_t	media_block_size,
		rtems_blkdev_bnum	media_block_count,
		bool	trace
	)

Allocates and initializes a RAM disk descriptor.

The block size will be media_block_size. The block count will be media_block_count. The disk storage area begins at area_begin. If area_begin is NULL, the memory will be allocated and zeroed. Sets the trace enable to trace.

Returns

Pointer to allocated and initialized ramdisk structure, or NULL if no memory is available.

Note

Runtime configuration example:

#include <rtems/ramdisk.h>
 
rtems_status_code create_ramdisk(
  const char *device,
  uint32_t media_block_size,
  rtems_blkdev_bnum media_block_count
)
{
  rtems_status_code sc;
  ramdisk *rd;
 
  rd = ramdisk_allocate(NULL, media_block_size, media_block_count, false);
  if (rd != NULL) {
    sc = rtems_blkdev_create(
      device,
      media_block_size,
      media_block_count,
      ramdisk_ioctl,
      rd
    );
  } else {
    sc = RTEMS_UNSATISFIED;
  }
 
  return sc;
}

ramdisk_register()

rtems_status_code ramdisk_register	(	uint32_t	media_block_size,
		rtems_blkdev_bnum	media_block_count,
		bool	trace,
		const char *	disk
	)

Allocates, initializes and registers a RAM disk.

The block size will be media_block_size. The block count will be media_block_count. The disk storage will be allocated. Sets the trace enable to trace. Registers a device node with disk name path disk. The registered device number will be returned in dev.

Return values

RTEMS_SUCCESSFUL	Successful operation.
RTEMS_UNSATISFIED	Something is wrong.

Variable Documentation

rtems_ramdisk_configuration

rtems_ramdisk_config rtems_ramdisk_configuration[]

extern

External reference to the RAM disk configuration table describing each RAM disk in the system.

The configuration table is provided by the application.

rtems_ramdisk_configuration_size

size_t rtems_ramdisk_configuration_size

extern

External reference the size of the RAM disk configuration table rtems_ramdisk_configuration.

The configuration table size is provided by the application.