[U-Boot] Fat32 and VFAT support

[michael <trimarchi@gandalf.sssup.it>]

Hi eric,

Eric Nelson wrote:
> Hello all,
>
> I've recently been looking into a problem loading files from a FAT32 filesystem
> and (re)discovered that there are issues with this code.
>
> Some of the symptoms are related to problems discussed in a thread back in
> April titled "USB SUPPORT & get_vfatname".
>
> 	http://lists.denx.de/pipermail/u-boot/2008-April/033117.html
>
> I ran into the issue(s) on an SD(MMC) card when I noticed a failure to load
> a certain file from the card.
>
> I've been able to narrow down a set of problems in fs/fat.c. I'm not sure
> when I'll have the time to generate a proper patch, but wanted to at least
> write some notes on the nature of the problem to save others some grief.
>
> The first problem I encountered was that the main loop in fs/fat.c/do_fat_read
> was built for fixed-size root directories. The Microsoft document
> 	"FAT: General Overview of On-Disk Format"
> says this on page 22:
> 	"For FAT32, the root directory can be of variable size and is a
> 	cluster chain, just like any other ..."
>
> When running the command:
>
> 	fatls mmc 0
>
>   
I try to investigate but I don't have spare time to fix. I send to the list
an linux-user space program that use the u-boot routine to read on the 
image.
You can use that to track down the problem.
Regards Michael