Great Performance from FullFAT

Great Performance from FullFAT

Today I managed to find some time to test the performance of FullFAT so far. (Always good to know your heading in the right direction).

I got some very promising results, testing on BlackFIN hardware, in comparison to a port of the FreeDOS fat driver:

The performance shows figures, for directory tree traversal using long filenames.
FreeDOS took 232982011 Core Clock Cycles.
FullFAT took only 3357211 Core Clock Cycles.

That shows that the FullFAT algorithm for directory tree traversal, and long-filename handling is 70x faster.
The test involved invoking the ls command, and seeing how long it took, using each driver.

I’ve also improved the portability of the entire framework, by ensuring that there are no memory alignment issues. The only platform portability that is required is to create memory access routines for BIG ENDIAN devices, and also those devices that do not have single byte access.

All these options will be easily configurable in a config.h header file.

These results surprised me a little, as I thought my directory tree traversal algorithm wasn’t particularly lean, I’ll see if I can improve even further later. Right now, stability across all platforms is the main priority.

The next small task is to bring FAT32 compatibility in-line with FAT16. Then i’ll be traversing the FAT tables, and reading files as efficiently as possible.

I’ll write more at a later date to keep you informed with the progress.