Nand flash and blob

Nand flash and blob

[Gabriel Goldstein]

Hello,

I'm working on a arm based design where I have a 16MB Sandisk/Samsung
nand flash device.  I think I have the Linux side settled buy using the
standard MTD driver. 

I'm using BLOB and I'd like to know what people are doing to get the
system loaded.  I have zImage, params, and ramdisk that I want to use my
NAND device to store these blocks.

Thanks,

Gabriel


Gabriel Goldstein
Anidea Engineering, Inc.
Fort Lauderdale, FL
anidea@earthlink.net
Phone:  954-254-9898
Fax:  240-368-8982

Re: Nand flash and blob

[Thomas Gleixner]

On Monday 25 November 2002 17:49, Gabriel Goldstein wrote:
> Hello,
>
> I'm working on a arm based design where I have a 16MB Sandisk/Samsung
> nand flash device.  I think I have the Linux side settled buy using the
> standard MTD driver.
>
> I'm using BLOB and I'd like to know what people are doing to get the
> system loaded.  I have zImage, params, and ramdisk that I want to use my
> NAND device to store these blocks.
You will have to extend block to handle NAND. You could use the nand driver 
code from mtd-cvs for this. Be aware that you have to handle bad blocks, as 
your chip can have factory marked bad blocks.

On my system I have 1MB bootflash, where the bootloader, zImage and params are 
stored and my root filesystem is on a JFFS2 partition on NAND. Thats the 
fastest way to go along I think.

-- 
Thomas
____________________________________________________
linutronix - competence in embedded & realtime linux
http://www.linutronix.de
mail: tglx@linutronix.de

RE: Nand flash and blob

[Gabriel Goldstein]

This is interesting.  I was planning on storing my ramdisk image in the
nand flash and still having blob expand it to ram.  I can see benefits
to both ways.  If I store the ramdisk.gz in flash, I will always have a
good image to boot up to, if I store it directly in nand, I could have
persistant information much easier.

How do you handle the aspect of all of the dev devices?  Are they part
of the root file system in ram still?

If I wanted to make a JFFS image, how do I take a directory and make a
file system image that I could load though blob?  Or how else would I
get it in there?

Thanks,

Gabriel

-----Original Message-----
From: Thomas Gleixner [mailto:tglx@linutronix.de] 
Sent: Monday, November 25, 2002 12:16 PM
To: anidea@earthlink.net; linux-mtd@lists.infradead.org
Subject: Re: Nand flash and blob

On Monday 25 November 2002 17:49, Gabriel Goldstein wrote:
> Hello,
>
> I'm working on a arm based design where I have a 16MB Sandisk/Samsung
> nand flash device.  I think I have the Linux side settled buy using
the
> standard MTD driver.
>
> I'm using BLOB and I'd like to know what people are doing to get the
> system loaded.  I have zImage, params, and ramdisk that I want to use
my
> NAND device to store these blocks.
You will have to extend block to handle NAND. You could use the nand
driver 
code from mtd-cvs for this. Be aware that you have to handle bad blocks,
as 
your chip can have factory marked bad blocks.

On my system I have 1MB bootflash, where the bootloader, zImage and
params are 
stored and my root filesystem is on a JFFS2 partition on NAND. Thats the

fastest way to go along I think.

-- 
Thomas
____________________________________________________
linutronix - competence in embedded & realtime linux
http://www.linutronix.de
mail: tglx@linutronix.de

Re: Nand flash and blob

[Thomas Gleixner]

On Monday 25 November 2002 18:28, Gabriel Goldstein wrote:
> This is interesting.  I was planning on storing my ramdisk image in the
> nand flash and still having blob expand it to ram.  I can see benefits
> to both ways.  If I store the ramdisk.gz in flash, I will always have a
> good image to boot up to, if I store it directly in nand, I could have
> persistant information much easier.
If youre not going to have a lot of changing environment, there is no real 
reason to use a ramdisk. 

> How do you handle the aspect of all of the dev devices?  Are they part
> of the root file system in ram still?
My root fs is on JFFS2 and the /dev/ directory is on there

> If I wanted to make a JFFS image, how do I take a directory and make a
> file system image that I could load though blob?  Or how else would I
> get it in there?
You mean a JFFS2 image ? Either you boot your Kernel via NFS, mount your FLASH 
with JFFS2 and copy all the stuff you need over there. The other way is you 
build up your root fs in a directory and use mkfs.jffs2, which is in 
mtd/utils, to build a fs-image. Then you still have to modify blob to burn it 
into the flash. Read also http://www.linux-mtd.infradead.org/tech/nand.html

-- 
Thomas
____________________________________________________
linutronix - competence in embedded & realtime linux
http://www.linutronix.de
mail: tglx@linutronix.de

Re: Nand flash and blob

[Charles Manning]

There are conceptually two ways of doing this:
* Use reserved NAND blocks to store the image.
* Store the image in a NAND file system (JFFS2 or YAFFS).

The second option has various advantages in that the image can then be 
transferred via file system copies. I have done this for WinCE, but other 
people have done this for Linux..

Nick Bane has done some mork to transfer YAFFS images into the device under 
bootloader control. See 
http://www.toby-churchill.org/Distribution/distribution.html

-- CHarles




On Tue, 26 Nov 2002 05:49, Gabriel Goldstein wrote:
> Hello,
>
> I'm working on a arm based design where I have a 16MB Sandisk/Samsung
> nand flash device.  I think I have the Linux side settled buy using the
> standard MTD driver.
>
> I'm using BLOB and I'd like to know what people are doing to get the
> system loaded.  I have zImage, params, and ramdisk that I want to use my
> NAND device to store these blocks.
>
> Thanks,
>
> Gabriel
>
>
> Gabriel Goldstein
> Anidea Engineering, Inc.
> Fort Lauderdale, FL
> anidea@earthlink.net
> Phone:  954-254-9898
> Fax:  240-368-8982