File system API

intdo_fat_fsload(structcmd_tbl*cmdtp, intflag, intargc, char*constargv[])

Run the fatload command

Parameters

struct cmd_tbl *cmdtp

Command information for fatload

int flag

Command flags (CMD_FLAG_...)

int argc

Number of arguments

char *const argv[]

List of arguments

Return

result (see enum command_ret_t)

intdo_ext2load(structcmd_tbl*cmdtp, intflag, intargc, char*constargv[])

Run the ext2load command

Parameters

struct cmd_tbl *cmdtp

Command information for ext2load

int flag

Command flags (CMD_FLAG_...)

int argc

Number of arguments

char *const argv[]

List of arguments

Return

result (see enum command_ret_t)

voidfs_set_type(inttype)

Tell fs layer which filesystem type is used

Parameters

int type

Filesystem type to use (FS_TYPE...)

Description

This is needed when reading from a non-block device such as sandbox. It does a similar job to fs_set_blk_dev() but just sets the filesystem type instead of detecting it and loading it on the block device

voidfs_close(void)

Unset current block device and partition

Parameters

void

no arguments

Description

fs_close() closes the connection to a file system opened with either fs_set_blk_dev() or fs_set_dev_with_part().

Many file functions implicitly call fs_close(), e.g. fs_closedir(), fs_exist(), fs_ln(), fs_ls(), fs_mkdir(), fs_read(), fs_size(), fs_write(), fs_unlink(), fs_rename().

intfs_get_type(void)

Get type of current filesystem

Parameters

void

no arguments

Return

filesystem type

Description

Returns filesystem type representing the current filesystem, or FS_TYPE_ANY for any unrecognised filesystem.

constchar*fs_get_type_name(void)

Get type of current filesystem

Parameters

void

no arguments

Return

Pointer to filesystem name

Description

Returns a string describing the current filesystem, or the sentinel "unsupported" for any unrecognised filesystem.

intfs_read(constchar*filename, ulongaddr, loff_toffset, loff_tlen, loff_t*actread)

read file from the partition previously set by fs_set_blk_dev()

Parameters

const char *filename

full path of the file to read from

ulong addr

address of the buffer to write to

loff_t offset

offset in the file from where to start reading

loff_t len

the number of bytes to read. Use 0 to read entire file.

loff_t *actread

returns the actual number of bytes read

Description

Note that not all filesystem drivers support either or both of offset != 0 and len != 0.

Return

0 if OK with valid actread, -1 on error conditions

intfs_write(constchar*filename, ulongaddr, loff_toffset, loff_tlen, loff_t*actwrite)

write file to the partition previously set by fs_set_blk_dev()

Parameters

const char *filename

full path of the file to write to

ulong addr

address of the buffer to read from

loff_t offset

offset in the file from where to start writing

loff_t len

the number of bytes to write

loff_t *actwrite

returns the actual number of bytes written

Description

Note that not all filesystem drivers support offset != 0.

Return

0 if OK with valid actwrite, -1 on error conditions

structfs_dirent

directory entry

Definition

struct fs_dirent {
 unsigned int type;
 loff_t size;
 u32 attr;
 struct rtc_time create_time;
 struct rtc_time access_time;
 struct rtc_time change_time;
 char name[FS_DIRENT_NAME_LEN];
};

Members

type

one of FS_DT_x (not a mask)

size

file size

attr

attribute flags (FS_ATTR_*)

create_time

time of creation

access_time

time of last access

change_time

time of last modification

name

file name

Description

A directory entry, returned by fs_readdir(). Returns information about the file/directory at the current directory entry position.

structfs_dir_stream

Structure representing an opened directory

Definition

struct fs_dir_stream {
 struct blk_desc *desc;
 int part;
};

Members

desc

block device descriptor

part

partition number

Description

Struct fs_dir_stream should be treated opaque to the user of fs layer. The fields desc and part are used by the fs layer. File system drivers pass additional private fields with the pointers to this structure.

structfs_dir_stream *fs_opendir(constchar*filename)

Open a directory

Parameters

const char *filename

path to the directory to open

Description

Return

A pointer to the directory stream or NULL on error and errno set appropriately

structfs_dirent *fs_readdir(structfs_dir_stream *dirs)

Read the next directory entry in the directory stream.

Parameters

struct fs_dir_stream *dirs

the directory stream

Description

fs_readir works in an analogous way to posix readdir(). The previously returned directory entry is no longer valid after calling fs_readdir() again. After fs_closedir() is called, the returned directory entry is no longer valid.

Return

the next directory entry (only valid until next fs_readdir() or fs_closedir() call, do not attempt to free()) or NULL if the end of the directory is reached.

voidfs_closedir(structfs_dir_stream *dirs)

close a directory stream

Parameters

struct fs_dir_stream *dirs

the directory stream

intfs_unlink(constchar*filename)

delete a file or directory

Parameters

const char *filename

Name of file or directory to delete

Description

If a given name is a directory, it will be deleted only if it’s empty

Return

0 on success, -1 on error conditions

intfs_mkdir(constchar*filename)

Create a directory

Parameters

const char *filename

Name of directory to create

Return

0 on success, -1 on error conditions

intfs_rename(constchar*old_path, constchar*new_path)

rename/move a file or directory

Parameters

const char *old_path

existing path of the file/directory to rename

const char *new_path

new path of the file/directory. If this points to an existing file or empty directory, the existing file/directory will be unlinked. If this points to a non-empty directory, the rename will fail.

Return

0 on success, -1 on error conditions

intdo_fs_types(structcmd_tbl*cmdtp, intflag, intargc, char*constargv[])

List supported filesystems.

Parameters

struct cmd_tbl *cmdtp

Command information for fstypes

int flag

Command flags (CMD_FLAG_...)

int argc

Number of arguments

char * const argv[]

List of arguments

Return

result (see enum command_ret_t)

intfs_read_alloc(constchar*fname, ulongsize, uintalign, void**bufp)

Allocate space for a file and read it

Parameters

const char *fname

Filename to read

ulong size

Size of file to read (must be correct!)

uint align

Alignment to use for memory allocation (0 for default: ARCH_DMA_MINALIGN)

void **bufp

On success, returns the allocated buffer with the nul-terminated file in it

Description

You must call fs_set_blk_dev() or a similar function before calling this, since that sets up the block device to use.

The file is terminated with a nul character

Return

0 if OK, -ENOMEM if out of memory, -EIO if read failed

intfs_load_alloc(constchar*ifname, constchar*dev_part_str, constchar*fname, ulongmax_size, ulongalign, void**bufp, ulong*sizep)

Load a file into allocated space

Parameters

const char *ifname

Interface name to read from (e.g. "mmc")

const char *dev_part_str

Device and partition string (e.g. "1:2")

const char *fname

Filename to read

ulong max_size

Maximum allowed size for the file (use 0 for 1GB)

ulong align

Alignment to use for memory allocation (0 for default)

void **bufp

On success, returns the allocated buffer with the nul-terminated file in it

ulong *sizep

On success, returns the size of the file

Description

The file is terminated with a nul character

Return

0 if OK, -ENOMEM if out of memory, -ENOENT if the file does not exist, -ENOMEDIUM if the device does not exist, -E2BIG if the file is too large (greater than max_size), -EIO if read failed