[U-Boot] Kernel to U-boot messaging and vice versa.

[Dev]

Thank You Hannes and Andy for replying back.

I agree that the kernel and U-boot are very old. There are many units deployed out in the field which are running these versions. Hence, we are stuck on these old versions.

There are some kernel modules which are running above linux kernel. When we try to field upgrade these deployed units, due to external failures for example power surge, these kernel modules hang in a bad state, which causes the unit unusable. In those conditions we want the unit to go through reset sequence.

Regards,
-Dev

> From: andy.pont at sdcsystems.com
> To: dsupehia at hotmail.com
> CC: u-boot at lists.denx.de
> Subject: RE: [U-Boot] Kernel to U-boot messaging and vice versa.
> Date: Tue, 17 Mar 2015 19:15:24 +0000
> 
> Dev wrote...
> 
> > I am new to U-boot development. We are using U-Boot 1.1.4 on a MIPS
> > 74Kc QCA 9557 processor, which is running Linux Kernel 2.6.32.27. 
> 
> Is there a reason why you have to be running a kernel from 2010 and a
> version of bootloader that is even older?  It makes life much easier to
> provide support if you can update to more recent versions and you never know
> they may already have fixed your problems!
> 
> > We have a situation were our firmware keeps hanging due to some issues. 
> 
> What is your "firmware" in this context?  As you rightly said, once the
> Linux kernel is running U-Boot is no more and if U-Boot is hanging then you
> aren't going to get to the kernel anyway!
> 
> > We are looking into a solution where U-boot and Kernel keep communicating
> > with each other every some minutes. If U-boot finds that there is no
> > communication, it will reset the board.
> 
> This sounds like it is the territory of watchdog timers.  I don't know that
> CPU to know whether it has one built in though, nor if the kernel supports
> it.
> 
> Andy.
>