Device Only File System

This structure defines the type of device table. More...

Files
file	devclose.c
	Maps Close Operation to rtems_io_close.
file	devfs_eval.c
	Evaluate Patch.
file	devfs_init.c
	Creates the Main Device Table.
file	devfs_mknod.c
	Creates an item in the main device table.
file	devfs_show.c
	Retrieves and Prints all the Device Registered in System.
file	devioctl.c
	Maps ioctl Operation to rtems_io_ioctl.
file	devopen.c
	Maps Open Operation to rtems_io_open.
file	devstat.c
	Gets the Device File Information.
file	devwrite.c
	Writes Operation to rtems_io_write.

Data Structures
struct	devFS_node
	Per Device Node Control Structure. More...
struct	devFS_data

Functions
void	devFS_eval_path (rtems_filesystem_eval_path_context_t *ctx)
	Evaluate Path.
int	devFS_open (rtems_libio_t *iop, const char *pathname, int oflag, mode_t mode)
	Maps Open Operation to rtems_io_open. More...
int	devFS_close (rtems_libio_t *iop)
	Maps Close Operation to rtems_io_close. More...
ssize_t	devFS_read (rtems_libio_t *iop, void *buffer, size_t count)
	Maps Read Operation to rtems_io_read. More...
ssize_t	devFS_write (rtems_libio_t *iop, const void *buffer, size_t count)
	Writes Operation to rtems_io_write. More...
int	devFS_ioctl (rtems_libio_t *iop, ioctl_command_t command, void *buffer)
	Maps ioctl Operation to rtems_io_ioctl. More...
int	devFS_stat (const rtems_filesystem_location_info_t *loc, struct stat *buf)
	Gets the Device File Information. More...
int	devFS_mknod (const rtems_filesystem_location_info_t *parentloc, const char *name, size_t namelen, mode_t mode, dev_t dev)
	Creates an item in the main device table. More...
int	devFS_initialize (rtems_filesystem_mount_table_entry_t *mt_entry, const void *data)
	Creates the Main Device Table. More...
void	devFS_Show (void)
	Retrieves and Prints all the Device Registered in System. More...

Variables
const rtems_filesystem_operations_table	devFS_ops
const rtems_filesystem_file_handlers_r	devFS_file_handlers

Detailed Description

This structure defines the type of device table.

Function Documentation

devFS_close()

int devFS_close

(

rtems_libio_t *

iop

)

Maps Close Operation to rtems_io_close.

This handler maps close operation to rtems_io_close.

Parameters

iop	This is the RTEMS's internal representation of file

Return values

the	same as close

devFS_initialize()

int devFS_initialize	(	rtems_filesystem_mount_table_entry_t *	mt_entry,
		const void *	data
	)

Creates the Main Device Table.

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

Parameters

mt_entry	The filesystem mount table entry.
data	Filesystem specific data.

Return values

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.

devFS_ioctl()

int devFS_ioctl	(	rtems_libio_t *	iop,
		ioctl_command_t	command,
		void *	buffer
	)

Maps ioctl Operation to rtems_io_ioctl.

This handler maps ioctl operation to rtems_io_ioctl.

Parameters

iop	This is the RTEMS's internal representation of file
command	io control command
buffer	io control parameters

Return values

On	successful, this routine returns total bytes written. On error it returns -1 and errno is set to proper value.

devFS_mknod()

int devFS_mknod	(	const rtems_filesystem_location_info_t *	parentloc,
		const char *	name,
		size_t	namelen,
		mode_t	mode,
		dev_t	dev
	)

Creates an item in the main device table.

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.

See also

rtems_filesystem_mknod_t.

devFS_open()

int devFS_open	(	rtems_libio_t *	iop,
		const char *	pathname,
		int	oflag,
		mode_t	mode
	)

Maps Open Operation to rtems_io_open.

This handler maps open operation to rtems_io_open.

Parameters

iop	This is the RTEMS's internal representation of file.
pathname	a null-terminated string that starts with /dev.
oflag	access flags
mode	access mode

Return values

the	same as open

devFS_read()

ssize_t devFS_read	(	rtems_libio_t *	iop,
		void *	buffer,
		size_t	count
	)

Maps Read Operation to rtems_io_read.

This handler maps read operation to rtems_io_read.

Parameters

iop	This is the RTEMS's internal representation of file
buffer	memory location to store read data
count	how many bytes to read

Return values

On	successful, this routine returns total bytes read. On error it returns -1 and errno is set to proper value.

devFS_Show()

void devFS_Show

(

void

)

Retrieves and Prints all the Device Registered in System.

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.

devFS_stat()

int devFS_stat	(	const rtems_filesystem_location_info_t *	loc,
		struct stat *	buf
	)

Gets the Device File Information.

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

Parameters

loc	contains filesystem access information
buf	buffer to hold the device file's information

Return values

On	successful, this routine returns 0. On error it returns -1 and errno is set to proper value.

devFS_write()

ssize_t devFS_write	(	rtems_libio_t *	iop,
		const void *	buffer,
		size_t	count
	)

Writes Operation to rtems_io_write.

This handler maps write operation to rtems_io_write.

Parameters

iop	This is the RTEMS's internal representation of file
buffer	data to be written
count	how many bytes to write

Return values

On	successful, this routine returns total bytes written. On error it returns -1 and errno is set to proper value.

Variable Documentation

devFS_file_handlers

const rtems_filesystem_file_handlers_r devFS_file_handlers

The following defines the device-only filesystem operating handlers.

devFS_ops

const rtems_filesystem_operations_table devFS_ops

The following defines the device-only filesystem operating operations.