[U-Boot-Users] How to use u-boot to load kernel and file system to one partition in NAND

[Nancy Isaac]

Charles,

 

I currently have the kernel in NAND flash, but my NAND has two separate
partitions. One for Kernel and one for file system.  

 

The problem I have is not really how to put the kernel in NAND, but how
to upgrade it.  I don't really want to overwrite what I have, instead I
want to load another image and have u-boot be able to pick up one or the
other.  This way, I can have two copies and in case the new version is
bad, I can always have one to fall back on.  This is why, I was thinking
that either having a soft link to a file in a single partition nand or
have three separate partitions (two of them for kernel, one for file
system).

 

 

________________________________

From: Charles Krinke [mailto:ckrinke at istor.com] 
Sent: Thursday, November 02, 2006 1:24 PM
To: Nancy Isaac; u-boot-users at lists.sourceforge.net
Subject: RE: [U-Boot-Users] How to use u-boot to load kernel and file
system toone partition in NAND

 

Dear Nancy & "the list":

 

I have a similar problem to solve with a PPC8241 board which currently
has 2Mbyte NOR flash and 128Mbyte of NAND flash. Let me tell you how far
I have gotten and maybe someone else can offer some suggestions for both
of us.

 

In looking at u-boot, I can see in some jffs2 support in
common/cmd_jffs2.c and fs/jffs2 and it looks like u-boot can be
configured to boot a kernel in cramfs or jffs2. So based on that, I am
assuming that getting the kernel onto an mtdblock partition as jffs2
should allow u-boot to boot the kernel from NAND flash instead of its
current NOR flash. 

 

I am currently studying the code trying to figure out how to configure
this scenario.

 

Perhaps someone else can come in with a few suggestions for both of us.

 

Charles

 

________________________________

From: u-boot-users-bounces at lists.sourceforge.net
[mailto:u-boot-users-bounces at lists.sourceforge.net] On Behalf Of Nancy
Isaac
Sent: Thursday, November 02, 2006 12:13 PM
To: u-boot-users at lists.sourceforge.net
Subject: [U-Boot-Users] How to use u-boot to load kernel and file system
toone partition in NAND

 

 

I am trying to see if u-boot allows to have a single partition for both
kernel and file system in NAND Flash.

Currently, we have one 4M partition for kernel and the rest of the NAND
flash for file system.

But, I am looking for possible ways of upgrading the kernel in the
field.   

Currently, I am looking at two possible approaches:

1. add an extra partition in the NAND flash and keep the second kernel
in there and have some way in u-boot to decide which one to load.

2. if u-boot allows, have one single partition for both kernel and file
system and upload both kernel images and have a soft link to a kernel
image.

 

I can't find a way to do the second option above, but that would be
ideal for field upgrade.  Has anyone tried either of these approaches or
have any other idea of how to do this? I am new to using u-boot and
linux.

 

Thanks

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