Quadros extends range of embedded file systems

FAT file systems are commonly used in the embedded industry on removable memory that needs to be read by/written to a PC.

Typical FAT (file allocation table) file system implementations have inherent weaknesses that can lead to file and directory corruption if the system is interrupted during a write routine.

When a file is opened to modify this, the normal FAT process overwrites the existing data.

If the system was reset during that process, a portion of the file would have been changed before a new image was built and there would be no way to restore the original data.

There could also be a directory entry pointing to a cluster chain that no longer exists or a cluster chain with no directory entry.

RTXCfatfile-safe uses a journaling approach that leaves the original file unchanged until either a file flush or file close is called.

At that point the system performs an atomic switch of the file state and the new data becomes valid.

The system also includes a function call, Fcloseabort(), which allows file modifications to be aborted during a write, restoring the original data.

This is only possible because the original data is untouched until the entire write/file close process has been completed.