[U-Boot] Q: nand usage

[U-Boot] Q: nand usage

[Ran Shalit]

Hello,

When using the nand, with regards to its implementation in U-boot or linux,
does a good strategy would be to map Nand to areas with *space* between the
end of one area to the start on another ? It seems a good ideas becuase of
the bad block issue and the skipping of bad blocks. I did not find
information about the Nand usage.

Best Regards,

Ran

[U-Boot] Q: nand usage

[Wolfgang Denk]

Dear Ran Shalit,

In message <AANLkTimCUE1ZbFB3eupKYcO_9=Ls4hKbqW=U4v8XfBXU@mail.gmail.com> you wrote:
>
> When using the nand, with regards to its implementation in U-boot or linux,
> does a good strategy would be to map Nand to areas with *space* between the
> end of one area to the start on another ? It seems a good ideas becuase of
> the bad block issue and the skipping of bad blocks. I did not find
> information about the Nand usage.

Your question makes no sense.  NAND is not a memory device that could
be mapped to some address range - insted,itis a strage device that can
be accessed only through some controller interface, similar to the ATA
controller on a harddisk.

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
First study the enemy.  Seek weakness.
	-- Romulan Commander, "Balance of Terror", stardate 1709.2

[U-Boot] Q: nand usage

[ran shalit]

Hello,

I think my question was not very well expressed. I ment to ask about the
mapping of the partitions inside the NAND: Does each partitions need some
spare blocks (padding block) becuase of the bad block skipping in the Nand ?
As I said, I did not find any information about the strategy of mapping
partitions in the Nand. 

Best Regards,

Ran
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[U-Boot] Q: nand usage

[Wolfgang Denk]

Dear ran shalit,

In message <31183736.post@talk.nabble.com> you wrote:
> 
> I think my question was not very well expressed. I ment to ask about the
> mapping of the partitions inside the NAND: Does each partitions need some
> spare blocks (padding block) becuase of the bad block skipping in the Nand ?
> As I said, I did not find any information about the strategy of mapping
> partitions in the Nand. 

As you are talking about partitions, I assume you refert to the MTD
partitioning.  In this case the bad block handling needs to be done in
by the file system code, when you create a file system insinde one of
the partitions.

[Note that this differs from UBI, where bad block handling is done for
the whole device, independent of the volumes that you create on top of
it.]

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
When you die, the first thing you lose is your life. The  next  thing
is the illusions.                       - Terry Pratchett, _Pyramids_

[U-Boot] Q: nand usage

[ran shalit]

wd wrote:
> 
> 
>> I think my question was not very well expressed. I ment to ask about the
>> mapping of the partitions inside the NAND: Does each partitions need some
>> spare blocks (padding block) becuase of the bad block skipping in the
>> Nand ?
>> As I said, I did not find any information about the strategy of mapping
>> partitions in the Nand. 
> 
> As you are talking about partitions, I assume you refert to the MTD
> partitioning.  In this case the bad block handling needs to be done in
> by the file system code, when you create a file system insinde one of
> the partitions.
> 
> [Note that this differs from UBI, where bad block handling is done for
> the whole device, independent of the volumes that you create on top of
> it.]
> 
> 

Sorry, I probably use the wrong terms in my question. I do not mean
partition using file system,
but just saving files using the u-boot interface, for example saving the
kernel file in some space in the NAND and for the u-boot file in another
space in the NAND, and all done with the given write command in the uboot
(nand write...). And again with this u-boot interface I still need some
strategy for deciding where to put each file.

Thanks again,

Ran
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[U-Boot] Q: nand usage

[Scott Wood]

On Fri, 18 Mar 2011 11:54:43 -0700
ran shalit <ranshalit@gmail.com> wrote:

> 
> 
> 
> wd wrote:
> > 
> > 
> >> I think my question was not very well expressed. I ment to ask about the
> >> mapping of the partitions inside the NAND: Does each partitions need some
> >> spare blocks (padding block) becuase of the bad block skipping in the
> >> Nand ?
> >> As I said, I did not find any information about the strategy of mapping
> >> partitions in the Nand. 
> > 
> > As you are talking about partitions, I assume you refert to the MTD
> > partitioning.  In this case the bad block handling needs to be done in
> > by the file system code, when you create a file system insinde one of
> > the partitions.
> > 
> > [Note that this differs from UBI, where bad block handling is done for
> > the whole device, independent of the volumes that you create on top of
> > it.]
> > 
> > 
> 
> Sorry, I probably use the wrong terms in my question. I do not mean
> partition using file system,
> but just saving files using the u-boot interface, for example saving the
> kernel file in some space in the NAND and for the u-boot file in another
> space in the NAND, and all done with the given write command in the uboot
> (nand write...). And again with this u-boot interface I still need some
> strategy for deciding where to put each file.

Yes, when placing raw files in NAND, you want to leave some space for bad
blocks.

-Scott