Analog Devices VisualDSP++ 5.0 Service Manual page 522

Introduction
Introduction
The file system service (FSS) provides a portable and extensible means of
accessing embedded mass storage media from the Blackfin processor. It is
designed in such a way that support for file systems such as the FAT file
system (typically found on removable media such as SD cards and USB
flash drive memory sticks) and physical interfaces (such as the
ATA/ATAPI interface on the ADSP-BF54x family of processors) can be
added to an application with minimal effort. Support for the
ADSP-BF548 EZ-KIT Lite development board is provided with Visu-
alDSP++ 5.0 for FAT file systems on the ATA and the secure digital host
interfaces for access to the attached hard disk drive and the supplied SD
Card and USB flash memory drive.
An application interfaces with these drivers using a framework and API
known as the file system service (FSS). Once initialized, the application
can make direct calls to the FSS API functions
Reference" on page
C I/O interface provided with the I/O library of VisualDSP++ 5.0. Once
registered with the I/O library, calls to
routed to the FSS to provide seamless access to files on the mass storage
media. In this way, applications using the standard C I/O interface can be
readily ported to use the file system service. In addition to these functions,
support is provided for certain POSIX functions such as
,
rename() remove()
"Additional POSIX Functions Supported by the FSS" on page
While the FSS API provides support for extending the declaration of file
and directory names to use the Unicode UTF-8 (16-bit) specification, the
current implementation of the FSS caters only for ASCII file names
(8-bit).
Access to each mass storage media type in an application is provided by
registering a device driver, termed a physical interface driver (PID), with
the FSS. Each media is formatted for a particular file system (for example,
12-2
12-18), or if registered, using the extensible standard
, and so on. The functions available are outlined in
VisualDSP++ 5.0 Device Drivers and System
Services Manual for Blackfin Processors
("File System Service API
, , and so on are
fopen() fread()
opendir()
,
12-71.