/**
* @file
*
* @brief RAM Disk Block Device API
*/
/*
* Copyright (C) 2001 OKTET Ltd., St.-Petersburg, Russia
* Author: Victor V. Vengerov <vvv@oktet.ru>
*/
#ifndef _RTEMS_RAMDISK_H
#define _RTEMS_RAMDISK_H
#include <rtems.h>
#include <rtems/blkdev.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
* @defgroup rtems_ramdisk RAM Disk Device
*
* @ingroup rtems_blkdev
*
*/
/**@{**/
/**
* @name Static Configuration
*/
/**@{**/
/**
* @brief RAM disk configuration table entry.
*/
typedef struct rtems_ramdisk_config {
/**
* @brief RAM disk block size.
*/
uint32_t block_size;
/**
* @brief Number of blocks on this RAM disk.
*/
rtems_blkdev_bnum block_num;
/**
* @brief RAM disk location or @c NULL if RAM disk memory should be allocated
* dynamically.
*/
void *location;
} rtems_ramdisk_config;
/**
* @brief External reference to the RAM disk configuration table describing
* each RAM disk in the system.
*
* The configuration table is provided by the application.
*/
extern rtems_ramdisk_config rtems_ramdisk_configuration [];
/**
* @brief External reference the size of the RAM disk configuration table
* @ref rtems_ramdisk_configuration.
*
* The configuration table size is provided by the application.
*/
extern size_t rtems_ramdisk_configuration_size;
/**
* @brief RAM disk driver initialization entry point.
*/
rtems_device_driver ramdisk_initialize(
rtems_device_major_number major,
rtems_device_minor_number minor,
void *arg
);
/**
* RAM disk driver table entry.
*/
#define RAMDISK_DRIVER_TABLE_ENTRY \
{ \
ramdisk_initialize, \
NULL, NULL, NULL, NULL, NULL \
}
#define RAMDISK_DEVICE_BASE_NAME "/dev/rd"
/** @} */
/**
* @name Runtime Configuration
*/
/**@{**/
/**
* @brief RAM disk descriptor.
*/
typedef struct ramdisk {
/**
* @brief RAM disk block size, the media size.
*/
uint32_t block_size;
/**
* @brief Number of blocks on this RAM disk.
*/
rtems_blkdev_bnum block_num;
/**
* @brief RAM disk memory area.
*/
void *area;
/**
* @brief RAM disk is initialized.
*/
bool initialized;
/**
* @brief Indicates if memory is allocated by malloc() for this RAM disk.
*/
bool malloced;
/**
* @brief Trace enable.
*/
bool trace;
/**
* @brief Free the RAM disk at the block device delete request.
*/
bool free_at_delete_request;
} ramdisk;
int ramdisk_ioctl(rtems_disk_device *dd, uint32_t req, void *argp);
/**
* @brief Allocates and initializes a RAM disk descriptor.
*
* The block size will be @a media_block_size. The block count will be
* @a media_block_count. The disk storage area begins at @a area_begin. If
* @a area_begin is @c NULL, the memory will be allocated and zeroed. Sets the
* trace enable to @a trace.
*
* @return Pointer to allocated and initialized ramdisk structure, or @c NULL
* if no memory is available.
*
* @note
* Runtime configuration example:
* @code
* #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;
* }
* @endcode
*/
ramdisk *ramdisk_allocate(
void *area_begin,
uint32_t media_block_size,
rtems_blkdev_bnum media_block_count,
bool trace
);
void ramdisk_free(ramdisk *rd);
static inline void ramdisk_enable_free_at_delete_request(ramdisk *rd)
{
rd->free_at_delete_request = true;
}
/**
* @brief Allocates, initializes and registers a RAM disk.
*
* The block size will be @a media_block_size. The block count will be
* @a media_block_count. The disk storage will be allocated. Sets the trace
* enable to @a trace. Registers a device node with disk name path @a disk.
* The registered device number will be returned in @a dev.
*
* @retval RTEMS_SUCCESSFUL Successful operation.
* @retval RTEMS_UNSATISFIED Something is wrong.
*/
rtems_status_code ramdisk_register(
uint32_t media_block_size,
rtems_blkdev_bnum media_block_count,
bool trace,
const char *disk
);
/** @} */
/** @} */
#ifdef __cplusplus
}
#endif
#endif
