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- /****************************************************************************
- * drivers/ramdisk.c
- *
- * Copyright (C) 2008-2009, 2011 Gregory Nutt. All rights reserved.
- * Author: Gregory Nutt <gnutt@nuttx.org>
- *
- * 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.
- * 3. Neither the name NuttX nor the names of its contributors may be
- * used to endorse or promote products derived from this software
- * without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
- * COPYRIGHT OWNER 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.
- *
- ****************************************************************************/
- /****************************************************************************
- * Included Files
- ****************************************************************************/
- #include <nuttx/config.h>
- #include <sys/types.h>
- #include <sys/ioctl.h>
- #include <stdint.h>
- #include <stdbool.h>
- #include <stdio.h>
- #include <stdlib.h>
- #include <string.h>
- #include <debug.h>
- #include <errno.h>
- #include <nuttx/kmalloc.h>
- #include <nuttx/fs/fs.h>
- #include <nuttx/ramdisk.h>
- /****************************************************************************
- * Private Definitions
- ****************************************************************************/
- /****************************************************************************
- * Private Types
- ****************************************************************************/
- struct rd_struct_s
- {
- uint32_t rd_nsectors; /* Number of sectors on device */
- uint16_t rd_sectsize; /* The size of one sector */
- #ifdef CONFIG_FS_WRITABLE
- bool rd_writeenabled; /* true: can write to ram disk */
- uint8_t *rd_buffer; /* RAM disk backup memory */
- #else
- const uint8_t *rd_buffer; /* ROM disk backup memory */
- #endif
- };
- /****************************************************************************
- * Private Function Prototypes
- ****************************************************************************/
- static int rd_open(FAR struct inode *inode);
- static int rd_close(FAR struct inode *inode);
- static ssize_t rd_read(FAR struct inode *inode, unsigned char *buffer,
- size_t start_sector, unsigned int nsectors);
- #ifdef CONFIG_FS_WRITABLE
- static ssize_t rd_write(FAR struct inode *inode, const unsigned char *buffer,
- size_t start_sector, unsigned int nsectors);
- #endif
- static int rd_geometry(FAR struct inode *inode, struct geometry *geometry);
- static int rd_ioctl(FAR struct inode *inode, int cmd, unsigned long arg);
- /****************************************************************************
- * Private Data
- ****************************************************************************/
- static const struct block_operations g_bops =
- {
- rd_open, /* open */
- rd_close, /* close */
- rd_read, /* read */
- #ifdef CONFIG_FS_WRITABLE
- rd_write, /* write */
- #else
- NULL, /* write */
- #endif
- rd_geometry, /* geometry */
- rd_ioctl /* ioctl */
- };
- /****************************************************************************
- * Private Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: rd_open
- *
- * Description: Open the block device
- *
- ****************************************************************************/
- static int rd_open(FAR struct inode *inode)
- {
- fvdbg("Entry\n");
- return OK;
- }
- /****************************************************************************
- * Name: rd_closel
- *
- * Description: close the block device
- *
- ****************************************************************************/
- static int rd_close(FAR struct inode *inode)
- {
- fvdbg("Entry\n");
- return OK;
- }
- /****************************************************************************
- * Name: rd_read
- *
- * Description: Read the specified numer of sectors
- *
- ****************************************************************************/
- static ssize_t rd_read(FAR struct inode *inode, unsigned char *buffer,
- size_t start_sector, unsigned int nsectors)
- {
- struct rd_struct_s *dev;
- DEBUGASSERT(inode && inode->i_private);
- dev = (struct rd_struct_s *)inode->i_private;
- fvdbg("sector: %d nsectors: %d sectorsize: %d\n",
- start_sector, dev->rd_sectsize, nsectors);
- if (start_sector < dev->rd_nsectors &&
- start_sector + nsectors <= dev->rd_nsectors)
- {
- fvdbg("Transfer %d bytes from %p\n",
- nsectors * dev->rd_sectsize,
- &dev->rd_buffer[start_sector * dev->rd_sectsize]);
- memcpy(buffer,
- &dev->rd_buffer[start_sector * dev->rd_sectsize],
- nsectors * dev->rd_sectsize);
- return nsectors;
- }
- return -EINVAL;
- }
- /****************************************************************************
- * Name: rd_write
- *
- * Description: Write the specified number of sectors
- *
- ****************************************************************************/
- #ifdef CONFIG_FS_WRITABLE
- static ssize_t rd_write(FAR struct inode *inode, const unsigned char *buffer,
- size_t start_sector, unsigned int nsectors)
- {
- struct rd_struct_s *dev;
- DEBUGASSERT(inode && inode->i_private);
- dev = (struct rd_struct_s *)inode->i_private;
- fvdbg("sector: %d nsectors: %d sectorsize: %d\n",
- start_sector, dev->rd_sectsize, nsectors);
- if (!dev->rd_writeenabled)
- {
- return -EACCES;
- }
- else if (start_sector < dev->rd_nsectors &&
- start_sector + nsectors <= dev->rd_nsectors)
- {
- fvdbg("Transfer %d bytes from %p\n",
- nsectors * dev->rd_sectsize,
- &dev->rd_buffer[start_sector * dev->rd_sectsize]);
- memcpy(&dev->rd_buffer[start_sector * dev->rd_sectsize],
- buffer,
- nsectors * dev->rd_sectsize);
- return nsectors;
- }
- return -EFBIG;
- }
- #endif
- /****************************************************************************
- * Name: rd_geometry
- *
- * Description: Return device geometry
- *
- ****************************************************************************/
- static int rd_geometry(FAR struct inode *inode, struct geometry *geometry)
- {
- struct rd_struct_s *dev;
- fvdbg("Entry\n");
- DEBUGASSERT(inode);
- if (geometry)
- {
- dev = (struct rd_struct_s *)inode->i_private;
- geometry->geo_available = true;
- geometry->geo_mediachanged = false;
- #ifdef CONFIG_FS_WRITABLE
- geometry->geo_writeenabled = dev->rd_writeenabled;
- #else
- geometry->geo_writeenabled = false;
- #endif
- geometry->geo_nsectors = dev->rd_nsectors;
- geometry->geo_sectorsize = dev->rd_sectsize;
- fvdbg("available: true mediachanged: false writeenabled: %s\n",
- geometry->geo_writeenabled ? "true" : "false");
- fvdbg("nsectors: %d sectorsize: %d\n",
- geometry->geo_nsectors, geometry->geo_sectorsize);
-
- return OK;
- }
- return -EINVAL;
- }
- /****************************************************************************
- * Name: rd_ioctl
- *
- * Description: Return device geometry
- *
- ****************************************************************************/
- static int rd_ioctl(FAR struct inode *inode, int cmd, unsigned long arg)
- {
- struct rd_struct_s *dev ;
- void **ppv = (void**)((uintptr_t)arg);
- fvdbg("Entry\n");
- /* Only one ioctl command is supported */
- DEBUGASSERT(inode && inode->i_private);
- if (cmd == BIOC_XIPBASE && ppv)
- {
- dev = (struct rd_struct_s *)inode->i_private;
- *ppv = (void*)dev->rd_buffer;
- fvdbg("ppv: %p\n", *ppv);
- return OK;
- }
- return -ENOTTY;
- }
- /****************************************************************************
- * Public Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: ramdisk_register
- *
- * Description: Register the a ramdisk
- ****************************************************************************/
- #ifdef CONFIG_FS_WRITABLE
- int ramdisk_register(int minor, uint8_t *buffer, uint32_t nsectors,
- uint16_t sectsize, bool writeenabled)
- #else
- int romdisk_register(int minor, uint8_t *buffer, uint32_t nsectors,
- uint16_t sectsize)
- #endif
- {
- struct rd_struct_s *dev;
- char devname[16];
- int ret = -ENOMEM;
- fvdbg("buffer: %p nsectors: %d sectsize: %d\n", buffer, nsectors, sectsize);
- /* Sanity check */
- #ifdef CONFIG_DEBUG
- if (minor < 0 || minor > 255 || !buffer || !nsectors || !sectsize)
- {
- return -EINVAL;
- }
- #endif
- /* Allocate a ramdisk device structure */
- dev = (struct rd_struct_s *)kmalloc(sizeof(struct rd_struct_s));
- if (dev)
- {
- /* Initialize the ramdisk device structure */
- dev->rd_nsectors = nsectors; /* Number of sectors on device */
- dev->rd_sectsize = sectsize; /* The size of one sector */
- #ifdef CONFIG_FS_WRITABLE
- dev->rd_writeenabled = writeenabled; /* true: can write to ram disk */
- #endif
- dev->rd_buffer = buffer; /* RAM disk backup memory */
- /* Create a ramdisk device name */
- snprintf(devname, 16, "/dev/ram%d", minor);
- /* Inode private data is a reference to the ramdisk device stgructure */
- ret = register_blockdriver(devname, &g_bops, 0, dev);
- if (ret < 0)
- {
- fdbg("register_blockdriver failed: %d\n", -ret);
- kfree(dev);
- }
- }
- return ret;
- }
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