[U-Boot] freescale i.MX28 mxsboot NAND booting on mx28evk bad blocks

Scott Wood scottwood at freescale.com
Wed Mar 20 22:24:45 CET 2013


On 03/20/2013 04:20:07 PM, Paul B. Henson wrote:
> On Tue, Mar 19, 2013 at 06:23:27PM -0500, Scott Wood wrote:
> 
> > > I don't think this is having any functional impact, as the scrub
> > > component of burning a new nand image wipes out the bad blocks,
> >
> > You should not be routinely scrubbing NAND!
> >
> > The manufacturers put bad block information there for a reason.
> 
> Hmm, I was following the instructions in doc/README.mx28_common, which
> says to use "run update_nand_full" to burn the NAND image, and one
> component of that per include/configs/mx28evk.h is:
> 
> 	nand scrub -y 0x0 ${filesize}
> 
> Are the instructions/env script incorrect?

The env script is incorrect.  Otavio, Marek, what's going on here?

> I don't believe the bad blocks that linux finds are actual bad blocks,
> and definitely not factory bad blocks. They seem to show up as a
> byproduct of the way u-boot is burning the NAND image. They are always
> at the same addresses (I tried two different NAND chips), and only
> appear when u-boot is used to burn the bootstream, but not when  
> kobs-ng
> is used.

My guess is there's some mismatch regarding NAND layout, but someone  
more familiar with mx28 will need to answer that...

-Scott


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