[U-Boot] uboot redundancy.

[Sagar Heroorkar]

Hi All,

Before i start using your ( Joakim )approach. I would like to get some tips
from Wolfgang or someone who can assist me here.

I am working on nor flash which is 128 mb flash for the PPC4XX.

My  goal is to make uboot redundant. having other copy of uboot if one fails
to boot.
Architechure follows like this.

Totally there will be 3 uboots. *Golden uboot *is the one which has
basic logic to pick which uboot from *uboot 1 or uboot 2 (different copy)*.
uboot 1 and uboot 2 is flashed into some location of 16mb nor flash.

Steps follows like this.

1)G-boot picks up uboot1/uboot2 based on environment variable. Basically we
jumps to that uboot and start booting it from there.

When i analysed the approach what Joakim implemented in
http://www.mail-archive.com/u-boot@lists.denx.de/msg26918.html.
He uses something like link_off() for each of the global data.

* There will be too many link_offs() i have to use in uboot to make sure
each of the global data.
* As i will have 2 uboots which resides into seperate partitions. This
requies to build 2 uboots with different relotate_code logic/something .

I have read comments about this approach in the link what i pasted above.

I would really appriciate if anyone replies (especially Wolfgang ) about
whether to go head with this approach before i spent much time on this.
Also if anyone has already done similar implentation for any of the boards
let me know.

-Sagar
On Mon, Jul 19, 2010 at 4:36 PM, Joakim Tjernlund <
joakim.tjernlund at transmode.se> wrote:

>
>
> Sagar Heroorkar <sagar.heroorkar at gmail.com> wrote on 2010/07/19 15:26:20:
> >
> > Hi Wlfgang,
> >
> > resending this.
> >
> > Please do reply
> >
> > -Sagar
>
> > On Fri, Jul 16, 2010 at 3:12 PM, Sagar Heroorkar <
> sagar.heroorkar at gmail.com> wrote:
> > Hi Joakim,
> >
> > Graeme referred me to contact you for this.
> >
> > I am working on U-boot making it PIC for ppc 405ex based boards.
> > I see in the following link
> http://www.mail-archive.com/u-boot@lists.denx.de/
> > msg26918.html
> > that you have implemented similar thing on 83xx board.
> >
> > I have downloaded latest u-boot from ftp server of denx. I dont see the
> > functions what you have modified like LINKF_OFF() etc.
> > I would like to know where is the source code for that. Also is there any
> > document other than the mail thread that explains what you have chagned.
>
> Hi Sagar
>
> The source isn't in u-boot. It is only available as the patches I sent at
> the time.
> I don't have the patches handy as I am on vacation for 2 more weeks.
>
> >
> > Thanks in advance.
> >
> > -Sagar
> >
>
>