using system ACE for generic app data storage - file system intelligence required?

I have a V4FX12 application that could potentially benefit from having 
Gbytes of ROM data storage easily changeable through a CF card, so the 
system ACE CF thing looks sort of interesting.

We are trying to put together SW on a ML403 board based on xilkernel and 
the lwip ethernet stack. I am wondering how hard it would be to give the 
app access to a big table of data on the CF card.

Maybe I'm not looking in the right place, but I've seen no example 
designs or drivers for accessing the system ACE short of MontaVista 
Linux. I've read the white paper and system ACE FAQ and skimmed the 
datasheet. They don't come right out and say it, but give the impression 
that the app must have FAT file system awareness to use the CF card. It 
would be great if there were some simple way of accessing big table of 
read-only data (as the configuration functionality obviously does).

Has anyone here used the system ACE for generic storage? How was the 
experience?

thanks,
Jeff

Jeff Cunningham wrote:
> I have a V4FX12 application that could potentially benefit from having 
> Gbytes of ROM data storage easily changeable through a CF card, so the 
> system ACE CF thing looks sort of interesting.
> 
> We are trying to put together SW on a ML403 board based on xilkernel and 
> the lwip ethernet stack. I am wondering how hard it would be to give the 
> app access to a big table of data on the CF card.
> 
> Maybe I'm not looking in the right place, but I've seen no example 
> designs or drivers for accessing the system ACE short of MontaVista 
> Linux. I've read the white paper and system ACE FAQ and skimmed the 
> datasheet. They don't come right out and say it, but give the impression 
> that the app must have FAT file system awareness to use the CF card. It 
> would be great if there were some simple way of accessing big table of 
> read-only data (as the configuration functionality obviously does).
> 
> Has anyone here used the system ACE for generic storage? How was the 
> experience?
> 

You could use xilfatfs which is another library shipped in EDK along 
with xilkernel & lwip. The accesses to CF itself will be slow, and the
CF has to be formatted with FAT16 as explained here: 
http://www.xilinx.com/products/boards/ml403/reference_designs.htm
Check the section "Restoring ML403 Demo Images".

/Siva