File system API

int do_fat_fsload(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]): 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)

int do_ext2load(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]): 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)

void fs_set_type(int type): 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

void fs_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().

int fs_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.

const char *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.

int fs_read(const char *filename, ulong addr, loff_t offset, loff_t len, 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

int fs_write(const char *filename, ulong addr, loff_t offset, loff_t len, 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

struct fs_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.

struct fs_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.

struct fs_dir_stream *fs_opendir(const char *filename): Open a directory

Parameters

const char *filename: path to the directory to open

Description

Note

The returned struct fs_dir_stream should be treated opaque to the user of the fs layer.

Return

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

struct fs_dirent *fs_readdir(struct fs_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.

void fs_closedir(struct fs_dir_stream *dirs): close a directory stream

Parameters

struct fs_dir_stream *dirs: the directory stream

int fs_unlink(const char *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

int fs_mkdir(const char *filename): Create a directory

Parameters

const char *filename: Name of directory to create

Return

0 on success, -1 on error conditions

int do_fs_types(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]): 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)

int fs_read_alloc(const char *fname, ulong size, uint align, 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

int fs_load_alloc(const char *ifname, const char *dev_part_str, const char *fname, ulong max_size, ulong align, 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