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- /****************************************************************************
- * drivers/ramdisk.c
- *
- * 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.
- *
- ****************************************************************************/
- /****************************************************************************
- * Included Files
- ****************************************************************************/
- #include <nuttx/config.h>
- #include <sys/types.h>
- #include <sys/ioctl.h>
- #include <inttypes.h>
- #include <stdint.h>
- #include <stdbool.h>
- #include <stdio.h>
- #include <stdlib.h>
- #include <string.h>
- #include <assert.h>
- #include <debug.h>
- #include <errno.h>
- #include <nuttx/kmalloc.h>
- #include <nuttx/fs/fs.h>
- #include <nuttx/drivers/ramdisk.h>
- /****************************************************************************
- * Pre-processor Definitions
- ****************************************************************************/
- /* Helpers for rdflags */
- /* User input flags */
- #define RDFLAG_USER (RDFLAG_WRENABLED | RDFLAG_FUNLINK)
- #define RDFLAG_IS_WRENABLED(f) (((f) & RDFLAG_WRENABLED) != 0)
- #define RDFLAG_IS_FUNLINK(f) (((f) & RDFLAG_WRENABLED) != 0)
- /* Flag set when the RAM disk block driver is unlink */
- #define RDFLAG_UNLINK(f) do { (f) |= RDFLAG_UNLINKED; } while (0)
- #define RDFLAG_IS_UNLINKED(f) (((f) & RDFLAG_UNLINKED) != 0)
- /****************************************************************************
- * Private Types
- ****************************************************************************/
- struct rd_struct_s
- {
- uint32_t rd_nsectors; /* Number of sectors on device */
- uint16_t rd_sectsize; /* The size of one sector */
- #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
- uint8_t rd_crefs; /* Open reference count */
- #endif
- uint8_t rd_flags; /* See RDFLAG_* definitions */
- FAR uint8_t *rd_buffer; /* RAM disk backup memory */
- };
- /****************************************************************************
- * Private Function Prototypes
- ****************************************************************************/
- #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
- static void rd_destroy(FAR struct rd_struct_s *dev);
- static int rd_open(FAR struct inode *inode);
- static int rd_close(FAR struct inode *inode);
- #endif
- static ssize_t rd_read(FAR struct inode *inode, FAR unsigned char *buffer,
- blkcnt_t start_sector, unsigned int nsectors);
- static ssize_t rd_write(FAR struct inode *inode,
- FAR const unsigned char *buffer, blkcnt_t start_sector,
- unsigned int nsectors);
- static int rd_geometry(FAR struct inode *inode,
- FAR struct geometry *geometry);
- static int rd_ioctl(FAR struct inode *inode, int cmd,
- unsigned long arg);
- #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
- static int rd_unlink(FAR struct inode *inode);
- #endif
- /****************************************************************************
- * Private Data
- ****************************************************************************/
- static const struct block_operations g_bops =
- {
- #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
- rd_open, /* open */
- rd_close, /* close */
- #else
- 0, /* open */
- 0, /* close */
- #endif
- rd_read, /* read */
- rd_write, /* write */
- rd_geometry, /* geometry */
- rd_ioctl, /* ioctl */
- #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
- rd_unlink /* unlink */
- #endif
- };
- /****************************************************************************
- * Private Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: rd_destroy
- *
- * Description:
- * Free all resources used by the RAM disk
- *
- ****************************************************************************/
- #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
- static void rd_destroy(FAR struct rd_struct_s *dev)
- {
- finfo("Destroying RAM disk\n");
- /* We we configured to free the RAM disk memory when unlinked? */
- if (RDFLAG_IS_UNLINKED(dev->rd_flags))
- {
- /* Yes.. do it */
- kmm_free(dev->rd_buffer);
- }
- /* And free the block driver itself */
- kmm_free(dev);
- }
- #endif
- /****************************************************************************
- * Name: rd_open
- *
- * Description: Open the block device
- *
- ****************************************************************************/
- #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
- static int rd_open(FAR struct inode *inode)
- {
- FAR struct rd_struct_s *dev;
- DEBUGASSERT(inode && inode->i_private);
- dev = (FAR struct rd_struct_s *)inode->i_private;
- /* Increment the open reference count */
- dev->rd_crefs++;
- DEBUGASSERT(dev->rd_crefs > 0);
- finfo("rd_crefs: %d\n", dev->rd_crefs);
- return OK;
- }
- #endif
- /****************************************************************************
- * Name: rd_close
- *
- * Description: close the block device
- *
- ****************************************************************************/
- #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
- static int rd_close(FAR struct inode *inode)
- {
- FAR struct rd_struct_s *dev;
- DEBUGASSERT(inode && inode->i_private);
- dev = (FAR struct rd_struct_s *)inode->i_private;
- /* Increment the open reference count */
- DEBUGASSERT(dev->rd_crefs > 0);
- dev->rd_crefs--;
- finfo("rd_crefs: %d\n", dev->rd_crefs);
- #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
- /* Was that the last open reference to the RAM disk? */
- if (dev->rd_crefs == 0)
- {
- /* Yes.. Have we been unlinked? */
- if (RDFLAG_IS_UNLINKED(dev->rd_flags))
- {
- /* Yes.. Release all of the RAM disk resources */
- rd_destroy(dev);
- }
- }
- #endif
- return OK;
- }
- #endif
- /****************************************************************************
- * Name: rd_read
- *
- * Description: Read the specified number of sectors
- *
- ****************************************************************************/
- static ssize_t rd_read(FAR struct inode *inode, unsigned char *buffer,
- blkcnt_t start_sector, unsigned int nsectors)
- {
- FAR struct rd_struct_s *dev;
- DEBUGASSERT(inode && inode->i_private);
- dev = (FAR struct rd_struct_s *)inode->i_private;
- finfo("sector: %" PRIu32 " nsectors: %u sectorsize: %d\n",
- start_sector, nsectors, dev->rd_sectsize);
- if (start_sector < dev->rd_nsectors &&
- start_sector + nsectors <= dev->rd_nsectors)
- {
- finfo("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
- *
- ****************************************************************************/
- static ssize_t rd_write(FAR struct inode *inode, const unsigned char *buffer,
- blkcnt_t start_sector, unsigned int nsectors)
- {
- struct rd_struct_s *dev;
- DEBUGASSERT(inode && inode->i_private);
- dev = (struct rd_struct_s *)inode->i_private;
- finfo("sector: %" PRIu32 " nsectors: %u sectorsize: %d\n",
- start_sector, nsectors, dev->rd_sectsize);
- if (!RDFLAG_IS_WRENABLED(dev->rd_flags))
- {
- return -EACCES;
- }
- else if (start_sector < dev->rd_nsectors &&
- start_sector + nsectors <= dev->rd_nsectors)
- {
- finfo("Transfer %d bytes to %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;
- }
- /****************************************************************************
- * Name: rd_geometry
- *
- * Description: Return device geometry
- *
- ****************************************************************************/
- static int rd_geometry(FAR struct inode *inode, struct geometry *geometry)
- {
- struct rd_struct_s *dev;
- finfo("Entry\n");
- DEBUGASSERT(inode);
- if (geometry)
- {
- dev = (struct rd_struct_s *)inode->i_private;
- geometry->geo_available = true;
- geometry->geo_mediachanged = false;
- geometry->geo_writeenabled = RDFLAG_IS_WRENABLED(dev->rd_flags);
- geometry->geo_nsectors = dev->rd_nsectors;
- geometry->geo_sectorsize = dev->rd_sectsize;
- finfo("available: true mediachanged: false writeenabled: %s\n",
- geometry->geo_writeenabled ? "true" : "false");
- finfo("nsectors: %" PRIu32 " sectorsize: %" PRIi16 "\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)
- {
- FAR struct rd_struct_s *dev;
- FAR void **ppv = (void**)((uintptr_t)arg);
- finfo("Entry\n");
- /* Only one ioctl command is supported */
- DEBUGASSERT(inode && inode->i_private);
- if (cmd == BIOC_XIPBASE && ppv)
- {
- dev = (FAR struct rd_struct_s *)inode->i_private;
- *ppv = (FAR void *)dev->rd_buffer;
- finfo("ppv: %p\n", *ppv);
- return OK;
- }
- return -ENOTTY;
- }
- /****************************************************************************
- * Name: rd_unlink
- *
- * Description:
- * The block driver has been unlinked.
- *
- ****************************************************************************/
- #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
- static int rd_unlink(FAR struct inode *inode)
- {
- FAR struct rd_struct_s *dev;
- DEBUGASSERT(inode && inode->i_private);
- dev = (FAR struct rd_struct_s *)inode->i_private;
- /* Mark the pipe unlinked */
- RDFLAG_UNLINK(dev->rd_flags);
- /* Are the any open references to the driver? */
- if (dev->rd_crefs == 0)
- {
- /* No... release all resources held by the block driver */
- rd_destroy(dev);
- }
- return OK;
- }
- #endif
- /****************************************************************************
- * Public Functions
- ****************************************************************************/
- /****************************************************************************
- * 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)
- {
- struct rd_struct_s *dev;
- char devname[16];
- int ret = -ENOMEM;
- finfo("buffer: %p nsectors: %" PRIu32 " sectsize: %" PRIu16 "\n",
- buffer, nsectors, sectsize);
- /* Sanity check */
- #ifdef CONFIG_DEBUG_FEATURES
- if (minor < 0 || minor > 255 || !buffer || !nsectors || !sectsize)
- {
- return -EINVAL;
- }
- #endif
- /* Allocate a ramdisk device structure */
- dev = (struct rd_struct_s *)kmm_zalloc(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 */
- dev->rd_buffer = buffer; /* RAM disk backup memory */
- dev->rd_flags = rdflags & RDFLAG_USER;
- /* Create a ramdisk device name */
- snprintf(devname, 16, "/dev/ram%d", minor);
- /* Inode private data is a reference to the ramdisk device structure */
- ret = register_blockdriver(devname, &g_bops, 0, dev);
- if (ret < 0)
- {
- ferr("register_blockdriver failed: %d\n", -ret);
- kmm_free(dev);
- }
- }
- return ret;
- }
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