[U-Boot] Large Block USB Flash Drive Problem

[Barnes, Clifton A.]

From: l.pinguin at gmail.com [mailto:l.pinguin at gmail.com] On Behalf Of Remy Bohmer
Sent: Monday, June 01, 2009 12:04 PM
To: Barnes, Clifton A.
Cc: u-boot at lists.denx.de
Subject: Re: [U-Boot] Large Block USB Flash Drive Problem

> Hello,

> 2009/5/28 Barnes, Clifton A. <cabarnes at indesign-llc.com>:
> >        I have been trying out loading the Linux kernel using a USB
> > flash drive in the u-boot-2009.06-rc2 release and ran into a problem
> > with one of my flash drives.  This particular drive has a block size of
> > 2048 while the other drives have block sizes of 512.  The drives with a
> > block size of 512 work perfectly.  However, the flash drive with a block
> > size of 2048 fails during the 'usb start' command.  I traced this issue
> > to the Part_dos.c file and the function test_part_dos.  The buffer
> > allocated there is only 512 bytes.  When I changed it to 2048, the 'usb
> > start' command worked correctly and found the one storage device
> > connected.  This had no adverse affect with the flash drives that were
> > 512 bytes.  Should the macro DEFAULT_SECTOR_SIZE be changed to
> > accommodate larger block size usb flash drives?
> >
> >        The second problem came when I tried to use the FAT utilities.
> > When I ran 'fatls usb 0', it failed the same way as when the 'usb start'
> > failed before.  Naturally, I guessed that it was a buffer size problem
> > again.  I was able to trace the issue to the macro SECTOR_SIZE in fat.h.
> > I tried changing it to 2048, however, there is a check right below it
> > that fails if SECTOR_SIZE != FS_BLOCK_SIZE.  So, I assume that the
> > support isn't written to handle sector sizes that are different than the
> > FAT block size.  However, I went ahead and changed them both to 2048.
> > This fixed the issues with the FAT utilities partly.  I was able to run
> > 'fatls usb 0' and it listed the files but also some junk.  I'm guessing
> > it was grabbing junk after the files since the block size is too big.  I
> > was also able to run 'fatload usb 0 0x22000000 uImage' successfully and
> > boot the kernel successfully.  So, I think the fix has to be in the
> > SECTOR_SIZE macro in the fat.h file.  Can anyone with expertise in the
> > FAT implementation take a look at supporting different sector sizes for
> > larger block size flash drives?

> Well, there was a patch posted for this some time ago:
> http://www.mail-archive.com/u-boot@lists.denx.de/msg05444.html

> But, this patch broke several 512 byte blocksize devices, so I did not
> push it to mainline.
> You might take a look at it, maybe it solves your problem.
> If you can make it work properly with 512 byte devices as well, I am
> in for a patch...

> Kind Regards,

> Remy


Remy,

	Do you know if anyone is actively working on this issue?  I tried applying the patch to the most recent U-Boot but it doesn't apply cleanly.  If no one is working on it, I might try to take a look at updating the patch and fixing the issue.  Is this not a big issue with people using USB flash drives?  It seems I'm running into more and more "large block" flash drives.

	Also, while clicking around the Git repo, I noticed that USB Ethernet support for the AT91 micros was added to U-Boot development.  How far along is the USB Ethernet support?  Is it something that can be tested now?  

Thanks,
Clif