[U-Boot] bootlimit for arm? watchdog?

[U-Boot] bootlimit for arm? watchdog?

[Frans Meulenbroeks]

Hi,

I am looking for a mechanism to reboot into an alternative kernel in case of problems. While reading the doc I stumbled upon the bootlimit feature, with which I probably can do what I need to.
However: one problem. My system is an ARM system, and the manual says bootlimit is only for PPC.
Would this be difficult to add (or maybe does it exist already)?

One other thing that could help me is watchdog.
I saw on the email list that watchdog is supported, but the manual does not list it (or I really need new glasses). Is this a board specific feature?
Any further info or pointer to info is greatly appreciated.

Thanks alot!

Frans


      

[U-Boot] bootlimit for arm? watchdog?

[Wolfgang Denk]

Dear Frans Meulenbroeks,

sorry for the late reply.

In message <102881.89864.qm@web33602.mail.mud.yahoo.com> you wrote:
> 
> I am looking for a mechanism to reboot into an alternative kernel in case of problems. While reading the doc I stumbled upon the bootlimit feature, with which I probably can do what I need to.
> However: one problem. My system is an ARM system, and the manual says bootlimit is only for PPC.
> Would this be difficult to add (or maybe does it exist already)?

It is simple to port. You just need to find a  place  where  you  can
save  some  information  so  it  survives a CPU reset. Typically some
registers or some on-chip memory or  external,  battery-buffert  SRAM
have this property.

> One other thing that could help me is watchdog.
> I saw on the email list that watchdog is supported, but the manual does not list it (or I really need new glasses). Is this a board specific feature?

Board and/or CPU specific. Some processors have a builtin watchdog,
some boards use an external hardware watchdog chip.

> Any further info or pointer to info is greatly appreciated.

Hope this helps.

Ummm...

<curiosity>
Are you the Frans Meulenbroeks who worked on Minix/AtariST some 18+
years ago?
</curiosity>

Best regards,

Wolfgang Denk

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