Virtual File System Driver Overview

The Virtual File System driver for Picolo U4 H.264 PCI-104 is a memory-based file system driver. Each board appears as a file system populated with files organized as a directory tree. These files are managed using standard file management functions of the operating system.

The Virtual File System driver supports the following board features:

The top-level of the directory structure looks as follows:

Refer to the corresponding topic in File System Structure for more details.

You will see the complete virtual file system for this device. The command and result are displayed hereafter:

$ ls -g
total 0
drwxrwxrwx 6 root 0 2009-12-16 12:09 audio
-r--r--r-- 1 root 1288 2009-12-16 12:09 config.dtd
-rw-rw-rw- 1 root 0 2009-12-16 12:09 config.xml
-r--r--r-- 1 root 4377 2009-12-16 12:09 exceptions.dtd
-rw-rw-rw- 1 root 0 2009-12-16 12:09 exceptions.xml
drwxrwxrwx 6 root 0 2009-12-16 12:09 inputlines
drwxrwxrwx 6 root 0 2009-12-16 12:09 outputlines
drwxrwxrwx 2 root 0 2009-12-16 12:09 passthroughselector
drwxrwxrwx 6 root 0 2009-12-16 12:09 visual
drwxrwxrwx 2 root 0 2009-12-16 12:09 watchdog

The data acquired by the board are provided as binary files containing raw data:

Each data file is associated with a metadata file that contains a plain-text XML description of the captured data.

The board is controlled through plain-text XML files:

Every XML file is associated with a Document Type Definition (DTD) file that validates the syntax of the XML file.

There are three types of files on the Picolo H.264 file system: