NAND Flash Device and JFFS2 support

NAND Flash Device and JFFS2 support

[carl liao]

Hi All,

I back ported mtd snapshot 20050416 codes to 2.4.26 for AMD Au1200.
The NAND device could be identified and accessed via /dev/mtd/0 interface.
I even could mount /dev/mtdblock/0, copy file to it and umount it. But there is
so many warnings or ecc error messages!

So in order to properly use NAND Flash, how could I format and read/write
data to it? I want to put Linux root file system on the NAND. Is it a right choice?

Thanks in advance for you suggestions and help!

Carl Liao

Re: NAND Flash Device and JFFS2 support

[Artem B. Bityuckiy]

On Wed, 2005-04-20 at 22:47 +0800, carl liao wrote:
Hi All,
> 
> I back ported mtd snapshot 20050416 codes to 2.4.26 for AMD Au1200.
> The NAND device could be identified and accessed via /dev/mtd/0
interface.
> I even could mount /dev/mtdblock/0, copy file to it and umount it. But
there is
> so many warnings or ecc error messages!
> This is not normal that you see "so many warnings or ecc error
messages". Presumably you have problems with your driver.

So in order to properly use NAND Flash, how could I format and
read/write
> data to it?
> flash_eraseall -j to format.

Please, investigate carefully web site at
http://www.linux-mtd.infradead.org/index.html

> I want to put Linux root file system on the NAND. Is it a right
choice?
Depends on your requirements.

JFFS2 is a generally good choice if:
* you need on-flight compression
* you need unclean-reboot tolerance
* your flash isn't large, say, not larger then 64 MiB

-- 
Best Regards,
Artem B. Bityuckiy,
St.-Petersburg, Russia.

NAND Flash Device and JFFS2 support

[carl liao]

HI Artem,

On 2005-04-20 23:15:01, Artem B. Bityuckiy at dedekind@infradead.org wrote:

>On Wed, 2005-04-20 at 22:47 +0800, carl liao wrote:

>>I back ported mtd snapshot 20050416 codes to 2.4.26 for AMD Au1200.
>>The NAND device could be identified and accessed via /dev/mtd/0.
>>I even could mount /dev/mtdblock/0, copy file to it and umount it. 
>>But there is so many warnings or ecc error messages!
>
>This is not normal that you see "so many warnings or ecc error
>messages". Presumably you have problems with your driver.
>

So I will double check my NAND chip driver first of all.

>>So in order to properly use NAND Flash, how could I format and
>>read/write data to it?
>
>flash_eraseall -j to format.
>
>Please, investigate carefully web site at
>http://www.linux-mtd.infradead.org/index.html
>

Thanks all! I found a good post "Can you really write a jffs2 image with
nandwrite?"
at http://lists.infradead.org/pipermail/linux-mtd/2005-March/012045.html

>>I want to put Linux root file system on the NAND. Is it a right choice?
>
>Depends on your requirements.
>
>JFFS2 is a generally good choice if:
>    * you need on-flight compression
>    * you need unclean-reboot tolerance
>    * your flash isn't large, say, not larger then 64 MiB
>

If I just want to use the NAND /dev/mtdblock/0 as a raw device without JFFS2,
and just put a ramdisk iamge on it, how could I do? Will NTFL help in this
case?

Thanks in advance to all!

Carl Liao