From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ladislav Michl <Ladislav.Michl@seznam.cz>
Date: Thu, 28 Jan 2010 18:11:40 +0100
Subject: [U-Boot] How to use multiple env variables.
In-Reply-To: <006201caa031$81daeb10$a5206c6b@semco>
References: <00f001ca9fe8$011da6f0$a5206c6b@semco>
	<20100128094308.GA2220@localhost.localdomain>
	<006201caa031$81daeb10$a5206c6b@semco>
Message-ID: <20100128171140.GA2502@localhost.localdomain>
List-Id: <u-boot.lists.denx.de>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
To: u-boot@lists.denx.de

On Thu, Jan 28, 2010 at 09:19:37PM +0530, Shashi Kumar M.S wrote:
> Where should this variable swapos should be.

Both 'ospart' and 'swapos' are ordinary u-boot environment variables.

> 1. should this "swapos" be in one of the separate partition of the nand  
> flash so that can be set by the kernel.

Kernel itself doesn't keep any concept of envinronment variables, however
MTD drivers live in kernel space and are used by fw_setenv (see
u-boot/tools/env/README) program to alter envinroment variables stored
in flash.

> 2. or is it a u-boot environment variable set by the kernel (reading the  
> u-boot env from the kernel and updating the "swapos" env) after the
> copy of new kernel and ramdisk done.

Sorry, I cannot parse that.

Basic idea is just to write new kernel and rootfs and execute
$ fw_setenv swapos yes
then reboot board and U-Boot scripts I described earlier do the rest.

Best regards,
	ladis