[U-Boot] How to use multiple env variables.

[Ladislav Michl <Ladislav.Michl@seznam.cz>]

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