[U-Boot-Users] AT91 NAND om AT91SAM9260EK

[Ulf Samuelsson <ulf@atmel.com>]

> Hej,
> 
> Has anyone used the at91_nand driver on the AT91SAM9260EK?
> 
> I get bad erase blocks on every block that contaions data (written to
> nand flash with SAM-BA).  Seems like the read_oob (read out of bounds
> area) function is returning data from the in bounds area.
> 
> U-boot configs the nand flash to use hw ecc (syndrome) whereas the
> at91_nand seems to be setup to use soft ecc.
> 

According to recent conversations on U-Boot mailing list
U-boot can do a raw copy of a flash file system, but nothing more.
(Correct me if I have misunderstood)

This means that if there are faulty pages in the NAND flash, you are dead.
U-Boot needs to be able to map out JFFS2 or YAFFS(2) to be useful here.
I.E. NAND flash is not functional as a boot memory yet.

If I understand correctly, you can read a JFFS2 fs in U-Boot

With the SAM9260, you can boot from an external dataflash card,
containing Linux and a small file system.
When this has booted, I think you can create a JFFS2 file system on the 
NAND flash. This should contain the Linux image as well.

U-Boot should then after reset, be able to read the linux from
the JFFS2 file system and then boot.

I do not know if U-boot can fit into the NAND flash
and I have not tested anything of above, but I think it should work.
The programming time of the system 
will of course be significant, since you have to test the NAND flash
for bad sectors..


> If anyone has been down this path before, I would appreciate any
> pointers or assistance you can provide.
> 
> Michel
> 
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Best Regards
Ulf Samuelsson