AW: [ECOS] redboot and failed boot switchover

Sumit Chauhan sumitchauhan79@gmail.com
Sun Feb 6 08:07:00 GMT 2005


Hi Alexander,

What u said is correct but what if the ramdisk.gz is say corrupted, or
any other partition got corrupted in last upgrade (and say infact the
watchdog resetting timer process cannot be executed .. )

This is the situation I think alfred was pointing to .. 

That say kernel could be started, but it will panic when it cannot
mount the  rootfs partition or say run a specific application which
was critical ..
system will reset due to watchdog timer issuing an NMI .. 

If the scenario is like this (which I feel is also pretty much likely on system)
Then, what the system should be doing is that it should check how many
retries it has gone through trying to load a default image and after a
certain retries, it should execute a backup boot script, which will
say fecth a new image ..

For this, kernel (or any user plane application) and redboot need to
communicate .. application should reset a counter everytime there is a
successfull come up in the system ..
Redboot and application need to see this common area .. 
one place to do this could be say NVRAM .. 
but I was just looking at the redboot guides and it mentions that
redboot can also see the mtd partition area ..

Can some one tell me how from the bootloader can one write to some
area on flash (mtd or not) , which can also be checked by an
application in user plane ??

Cheers,
Sumit

On Thu, 3 Feb 2005 12:10:11 +0100, Neundorf, Alexander
<Alexander.Neundorf@jenoptik.com> wrote:
> 
> 
> > Von: ecos-discuss-owner@ecos.sourceware.org
> >
> > Hi,
> >
> > I have just started with redboot as a possible bootloader for
> > our system ..
> > but couldnt see if there is any direct for a feature like this :
> >
> > bootloader boots by default from the boot script a specific
> > kernel + root fs ..
> > (but just incase there is  a corruption / bad image or some thing) ,
> > it should maintain a retry count which can be used to monitor failed
> > boot up's ..
> 
> If you have crc's enabled redboot won't start the image if it is corrupt. If you have a backup image you can then start this backup image:
> fis load image; go; fis load backup; go
> 
> Maybe you can also do other things instead of loading a backup image.
> 
> Bye
> Alex
> 
> --
> Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos
> and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss
> 
>

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