[U-Boot] [RFC] Safe Linux Updater

[Mats Kärrman]

Dear Wolfgang,

I havn't seen the scripts of Alexandre but it sounds something like what
we have already implemented.

Wolfgang Denk wrote:
>   Please note that this is a feature standardized for example in the
>   Open Source Development Labs Carrier Grade Linux Requirements
>   Definition, which says something like: "CGL shall provide support
>   for detecting a repeating reboot cycle due to recurring failures
>   and will go to an offline state if this occurs."

As I read Alexandre, the aim is to revert to a previous functional image,
not to go to an offline state.

>  Normally you want to avoid all erase / write operations to
>   the boot loader and it's private data structures in the process of
>   a normal reboot / reset.

But a failing boot is not a normal boot. This should only occur when an
update fails. After a maximum number of failing boots, the old functional
image is used and there is no need to update the counter any more.

Best Regards,
Mats