Brian G Rhodes wrote:
> Those commands work for me from Linux to produce a working system.  I
> can't say it's entirely reliable reading and writing without ECC
> though.  You may want to spend the time to add a routine in the Linux
> davinci NAND driver to write those blocks using rbl's ECC layout and
> save yourself some potential headaches.

Some thoughts:

John, I recommend using JTAG to see what is going on inside your NAND chip - 
lets you read/write/erase blocks with or without OOB and works even when the 
board won't boot because of bad NAND contents. I use OpenOCD, which includes 
configs for some davinci EVMs and NAND flash layouts, with an Amontec 
JTAGKey-Tiny - total cost around 30 euro. Also good for bootloader debug etc.

What DaVinci device are you using? The DM355 RBL ignores ECC completely (see 
silicon errata document) but uses this wacky OOB layout on large page size NAND.

I am in the position of trying to work out a firmware upgrade path such that 
git kernel Linux (with "correct" OOB layout) can rewrite UBL (in DM355 RBL 
"infix" layout format).
The UBL shouldn't need valid ECC on DM355, but if I need it for other things I 
plan to use a software utility to calculate ECC and format the OOB data, then 
use the raw+oob write mode of mtd - I think I remember it can do that.. Will 
find out soon (!).

I am hoping to derive the software ECC calculation util from the GenECC tool 
described here:
http://processors.wiki.ti.com/index.php/NAND_ECC_Generation_for_DaVinci_Family_of_Devices

HTH,

--
Jon Povey
[email protected]

Racelogic is a limited company registered in England. Registered number 2743719 
.
Registered Office Unit 10, Swan Business Centre, Osier Way, Buckingham, Bucks, 
MK18 1TB .

The information contained in this electronic mail transmission is intended by 
Racelogic Ltd for the use of the named individual or entity to which it is 
directed and may contain information that is confidential or privileged. If you 
have received this electronic mail transmission in error, please delete it from 
your system without copying or forwarding it, and notify the sender of the 
error by reply email so that the sender's address records can be corrected. The 
views expressed by the sender of this communication do not necessarily 
represent those of Racelogic Ltd. Please note that Racelogic reserves the right 
to monitor e-mail communications passing through its network


_______________________________________________
Davinci-linux-open-source mailing list
[email protected]
http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source

Reply via email to