[U-Boot-Users] FW: USB SUPPORT & get_vfatname

[Ken.Fuchs at bench.com]

Michael Trimarchi wrote:

> In my spare time a try to change the do_fat_read to support 
> the chaining.

Thank you.  Please let me know of anything I can do to help.

Does this mean you are now able to duplicate the problem?

The "Microsoft Extensible Firmware Initiative FAT32 File System
Specification" white paper you quoted seems like a good reference
document for FAT32.  Is there anything better?

BTW, in working with partitions <= 32MB, I have used FAT12,
but fs/fat/fat.c clearly doesn't support FAT12 properly.
FAT12 can be useful for NOR flash devices which are often
small enough for all four primary partitions to be <= 32MB.
Is anyone else (trying to) use FAT12 via U-Boot?
My work-around for this problem has simply been force
partitions <= 32MB to contain FAT16 whenever U-Boot needs
to read file from them.

Sincerely,

Ken Fuchs

> -----Original Message-----
> From: michael [mailto:trimarchi at gandalf.sssup.it] 
> Sent: Friday, April 25, 2008 10:45
> To: Fuchs, Ken
> Cc: afilipi at applieddata.net; u-boot-users at lists.sourceforge.net
> Subject: Re: [U-Boot-Users] FW: USB SUPPORT & get_vfatname
> 
> 
> Hi,
> Ken.Fuchs at bench.com wrote:
> > Michael Trimarchi wrote:
> >
> >   
> >> confirm that the problem is in fat.c file and I will try to fix.
> >>     
> >
> > It has been confirmed that fatls does _not_ list
> > all files on FAT32 filesystems.
> >
> > There are _no_ reports of fatls failing to list
> > all files on FAT16 filesystems.  (There may be
> > an unrelated bug caused by all 512 directory
> > entries of FAT16 being used.)
> >
> > What additional information is needed to confirm
> > that the problem is in fat.c?
> >
> >   
> The problem is related to how fat.c manage the root directory. As 
> reported by
> microsoft
> in "FAT32, the root directory can be of variable size and is 
> a cluster 
> chain, just like any other directory is.
> The first cluster of the root directory on a FAT32 volume is 
> stored in 
> BPB_RootClus. Unlike other directories,
> the root directory itself on any FAT type does not have any 
> date or time 
> stamps, does not have a file name
> (other than the implied file name "\"), and does not contain "." and 
> ".." files as the first two directory entries in the directory.
> The only other special aspect of the root directory is that it is the 
> only directory on the FAT volume for
> which it is valid to have a file that has only the ATTR_VOLUME_ID 
> attribute bit set (see below)."
> > What is your response to the debug log you requested?
> > It was sent to the ml almost 18 hours ago and is
> > also quoted below.
> >   
> In my spare time a try to change the do_fat_read to support 
> the chaining.
> 
> Regards Michael
> 
>