/**
* @file libfs/devfs/devfs.h
*
* This include file contains all constants and structures associated
* with the 'device-only' filesystem.
*/
#ifndef _RTEMS_DEVFS_H
#define _RTEMS_DEVFS_H
#include <rtems/libio_.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
* This structure define the type of device table
*/
typedef struct
{
/** This member points to device name which is a null-terminated string */
const char *device_name;
/** This member is the name length of a device */
uint32_t device_name_length;
/** major number of a device */
rtems_device_major_number major;
/** minor number of a device */
rtems_device_minor_number minor;
/** device creation mode, only device file can be created */
mode_t mode;
} rtems_device_name_t;
/**
* This routine associates RTEMS status code with errno
*/
extern int rtems_deviceio_errno(rtems_status_code code);
/**
* The following defines the device table size. This values
* is configured during application configuration time by
* the user. The default value is set to 4.
*/
extern uint32_t rtems_device_table_size;
/**
* This handler maps open operation to rtems_io_open.
* @param iop This is the RTEMS's internal representation of file.
* @param pathname a null-terminated string that starts with /dev.
* @param flag access flags
* @param mode access mode
* @retval the same as open
*/
extern int devFS_open(
rtems_libio_t *iop,
const char *pathname,
uint32_t flag,
uint32_t mode
);
/**
* This handler maps close operation to rtems_io_close.
* @param iop This is the RTEMS's internal representation of file
* @retval the same as close
*/
extern int devFS_close(
rtems_libio_t *iop
);
/**
* This handler maps read operation to rtems_io_read.
* @param iop This is the RTEMS's internal representation of file
* @param buffer memory location to store read data
* @param count how many bytes to read
* @retval On successful, this routine returns total bytes read. On error
* it returns -1 and errno is set to proper value.
*/
extern ssize_t devFS_read(
rtems_libio_t *iop,
void *buffer,
size_t count
);
/**
* This handler maps write operation to rtems_io_write.
* @param iop This is the RTEMS's internal representation of file
* @param buffer data to be written
* @param count how many bytes to write
* @retval On successful, this routine returns total bytes written. On error
* it returns -1 and errno is set to proper value.
*/
extern ssize_t devFS_write(
rtems_libio_t *iop,
const void *buffer,
size_t count
);
/**
* This handler maps ioctl operation to rtems_io_ioctl.
* @param iop This is the RTEMS's internal representation of file
* @param command io control command
* @param buffer io control parameters
* @retval On successful, this routine returns total bytes written. On error
* it returns -1 and errno is set to proper value.
*/
extern int devFS_ioctl(
rtems_libio_t *iop,
uint32_t command,
void *buffer
);
/**
* This handler gets the device file information. This routine only set the following member of struct stat:
* st_dev : device number
* st_mode: device file creation mode, only two mode are accepted:
* S_IFCHR: character device file
* S_IFBLK: block device file
* @param loc contains filesystem access information
* @param buf buffer to hold the device file's information
* @retval On successful, this routine returns 0. On error
* it returns -1 and errno is set to proper value.
*/
extern int devFS_stat(
rtems_filesystem_location_info_t *loc,
struct stat *buf
);
/**
* This routine is invoked upon determination of a node type.
* Since this is a device-only filesystem, so there is only
* one node type in the system.
*
* @param pathloc contains filesytem access information, this
* parameter is ignored
* @retval always returns RTEMS_FILESYSTEM_DEVICE
*/
extern rtems_filesystem_node_types_t devFS_node_type(
rtems_filesystem_location_info_t *pathloc
);
/**
* This routine is invoked to determine if 'pathname' exists.
* This routine first check access flags, then it searches
* the device table to get the information.
*
* @param pathname device name to be searched
* @param flags access flags
* @param pathloc contains filesystem access information
* @retval upon success(pathname exists), this routines
* returns 0; if 'flag' is invalid, it returns -1 and errno
* is set to EIO; otherwise, it returns -1 and errno is set to ENOENT
*/
extern int devFS_evaluate_path(
const char *pathname,
size_t pathnamelen,
int flags,
rtems_filesystem_location_info_t *pathloc
);
/**
* This routine is given a path to evaluate and a valid start
* location. It is responsible for finding the parent node for
* a requested make command, setting pathloc information to
* identify the parent node, and setting the name pointer to
* the first character of the name of the new node. In device
* only filesystem, devices do not has a tree hierarchy, there
* are no parent-child relationship. So this routine is rather
* simple, it just set *name to path and returns
*
* @param path device path to be evaluated
* @param pathloc contains filesystem access information, this
* parameter is ignored
* @param name
* @retval always returns 0
*/
extern int devFS_evaluate_for_make(
const char *path,
rtems_filesystem_location_info_t *pathloc,
const char **name
);
/**
* This routine is invoked upon registration of a new device
* file. It is responsible for creating a item in the main
* device table. This routine searches the device table in
* sequential order, when found a empty slot, it fills the slot
* with proper values.
*
* @param path the device file name to be registered
* @param mode file mode, this parameter is ignored
* @param dev device major and minor number
* @param pathloc contains filesystem access information
* @retval upon success, this routine returns 0; if 'path'
* already exist, it returns -1 and errno is set to EEXIST;
* if device table is full, it returns -1 and errno is set
* to ENOMEM
*/
extern int devFS_mknod(
const char *path,
mode_t mode,
dev_t dev,
rtems_filesystem_location_info_t *pathloc
);
/**
* This routine is invoked upon rtems filesystem initialization.
* It is responsible for creating the main device table,
* initializing it to a known state, and set device file operation
* handlers. After this, the device-only filesytem is ready for use
*
* @param mt_entry The filesystem mount table entry.
* @param data Filesystem specific data.
* @retval upon success, this routine returns 0; otherwise it returns
* -1 and errno is set to proper value. The only error is when malloc
* failed, and errno is set to NOMEM.
*/
extern int devFS_initialize(
rtems_filesystem_mount_table_entry_t *mt_entry,
const void *data
);
/**
* This routine retrieves all the device registered in system, and
* prints out their detail information. For example, on one system,
* devFS_show will print out following message:
*
* /dev/console 0 0
* /dev/clock 1 0
* /dev/tty0 0 0
* /flash 2 0
*
* This routine is intended for debugging, and can be used by shell
* program to provide user with the system information.
*
* @retval 0
*/
extern int devFS_Show(void);
#ifdef __cplusplus
}
#endif
#endif
