2009-01-29 13:30:00     8GByte NAND flash, Yaffs2 or Jffs2

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2009-01-29 13:30:00     8GByte NAND flash, Yaffs2 or Jffs2

Izhar Eyal (ISRAEL)

Message: 68525   

 

Hello All,

 

We are making a project using the BF-561 and are using a Micron 8GB NAND flash. has anyone used such devices? how did you solve the two chips in one package issue?

 

If anyone can please detail, what is the best FS to use: YAFFS2 or JFFS2, and why.

 

Also, 8GB flash, can is be made as a single "folder"/"hard-drive", I've heard that some of the software layers are limited to 2GB/4GB, can you please detail which: FS (JFFS2/YAFSS2), MTD layer?

 

If MTD is limited, will the MTD concatening layer help?

 

Thanks, Izhar

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2009-01-29 13:43:40     Re: 8GByte NAND flash, Yaffs2 or Jffs2

Mike Frysinger (UNITED STATES)

Message: 68527   

 

we havent tried hooking up the nand parts where it's really multiple chips in one package to the async bank.  maybe try grepping the tree to see if someone else is supporting that part.

 

the 2008R1.5 release was limited to 32bits per device.  the next release should up that limit to 64bits, but we've never tested it as we dont have any parts that large.

 

but if you simply expose it as two 4gig devices, then it probably shouldnt be a problem.

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2009-01-29 15:34:13     Re: 8GByte NAND flash, Yaffs2 or Jffs2

Izhar Eyal (ISRAEL)

Message: 68537   

 

Hi Mike,

 

Thanks for the reply,

 

We thought about using those as 2, 4gig devices...but in partition struct, size cannot be 4gig (integer overflow during compilation), any idea why?

 

Also, what FS would you recommend, YAFFS2 or JFFS2 ?

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2009-01-29 16:00:35     Re: 8GByte NAND flash, Yaffs2 or Jffs2

Mike Frysinger (UNITED STATES)

Message: 68539   

 

like i said, the branch kernel uses 32bit ints and 4gig will not fit into 32bits.  just declare the size as 1 page smaller than 4gig to work around the issue.

 

yaffs is recommended for NAND devices regardless of size.

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2009-02-05 12:13:42     Re: 8GByte NAND flash, Yaffs2 or Jffs2

Izhar Eyal (ISRAEL)

Message: 68920   

 

It seems that YAFFS2 supports up to 2048 page size, our 8GB NAND is 4096 page size.

 

Do you know of any patch/fix for the YAFFS/JFFS2 to support this?

 

I did see on the internet a git of nandsim using 8GB on a UBIFS but could not locate the file on the servers.

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2009-02-05 12:16:50     Re: 8GByte NAND flash, Yaffs2 or Jffs2

Mike Frysinger (UNITED STATES)

Message: 68921   

 

we dont really track yaffs development.  you can ask them here:

http://www.yaffs.net/

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