Device Virtual File System

Modules
	File Descriptor
	File System API
	File API
	File POSIX API
Functions
void	dfs_init (void)
void	dfs_lock (void)
void	dfs_unlock (void)
const char *	dfs_subdir (const char *directory, const char *filename)
char *	dfs_normalize_path (const char *directory, const char *filename)

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Detailed Description

The DFS (Device Virtual File System) is a vfs file system of RT-Thread RTOS, which is focused on embedded device. VFS is an abstraction layer on top of a more concrete file system. The purpose of a VFS is to allow client applications to access different types of concrete file systems in a uniform way.

Figure 2: Device Virtual File System Architecture

The DFS specifies an interface between the kernel and a concrete file system. Therefore, it is easy to add support for new file system types to the kernel simply by fulfilling the interface.

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Function Documentation

void dfs_init

(

void

)

this function will initialize device file system.

void dfs_lock

(

void

)

this function will lock device file system.

Note:

please don't invoke it on ISR.

void dfs_unlock

(

void

)

this function will lock device file system.

Note:

please don't invoke it on ISR.

const char* dfs_subdir	(	const char *	directory,
		const char *	filename
	)

this function will return a sub-path name under directory.

Parameters:

directory	the parent directory.
filename	the filename.

Returns:

the subdir pointer in filename

char* dfs_normalize_path	(	const char *	directory,
		const char *	filename
	)

this function will normalize a path according to specified parent directory and file name.

Parameters:

directory	the parent path
filename	the file name

Returns:

the built full file path (absolute path)