incubator-nuttx/include/nuttx/drivers/ramdisk.h

115 lines
4.1 KiB
C

/****************************************************************************
* include/nuttx/drivers/ramdisk.h
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
#ifndef __INCLUDE_NUTTX_DRIVERS_RAMDISK_H
#define __INCLUDE_NUTTX_DRIVERS_RAMDISK_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include <stdbool.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Values for rdflags */
#define RDFLAG_WRENABLED (1 << 0) /* Bit 0: 1=Can write to RAM disk */
#define RDFLAG_FUNLINK (1 << 1) /* Bit 1: 1=Free memory when unlinked */
/* For internal use by the driver only */
#define RDFLAG_UNLINKED (1 << 2) /* Bit 2: 1=Driver has been unlinked */
/****************************************************************************
* Type Definitions
****************************************************************************/
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
#ifdef __cplusplus
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
/****************************************************************************
* Name: ramdisk_register or romdisk_register
*
* Description:
* Non-standard function to register a ramdisk or a romdisk
*
* Input Parameters:
* minor: Selects suffix of device named /dev/ramN, N={1,2,3...}
* nsectors: Number of sectors on device
* sectize: The size of one sector
* rdflags: See RDFLAG_* definitions
* buffer: RAM disk backup memory
*
* Returned Value:
* Zero on success; a negated errno value on failure.
*
****************************************************************************/
int ramdisk_register(int minor, FAR uint8_t *buffer, uint32_t nsectors,
uint16_t sectsize, uint8_t rdflags);
#define romdisk_register(m,b,n,s) ramdisk_register(m,(FAR uint8_t *)b,n,s,0)
/****************************************************************************
* Name: mkrd
*
* Description:
* This is a wrapper function around ramdisk_register. It combines the
* necessary operations to create a RAM disk into a single callable
* function. Memory for the RAM disk is allocated, appropriated, from
* the kernel heap (in build modes where there is a distinct kernel heap).
*
* Input Parameters:
* minor: Selects suffix of device named /dev/ramN, N={1,2,3...}
* nsectors: Number of sectors on device
* sectize: The size of one sector
* rdflags: See RDFLAG_* definitions. Typically
* RDFLAG_WRENABLED | RDFLAG_FUNLINK
*
* Returned Value:
* Zero on success; a negated errno value on failure.
*
****************************************************************************/
#ifdef CONFIG_DRVR_MKRD
int mkrd(int minor, uint32_t nsectors, uint16_t sectsize, uint8_t rdflags);
#endif
#undef EXTERN
#ifdef __cplusplus
}
#endif
#endif /* __INCLUDE_NUTTX_DRIVERS_RAMDISK_H */