[U-Boot] bootlimit for arm? watchdog?

[Wolfgang Denk]

Dear Frans Meulenbroeks,

sorry for the late reply.

In message <102881.89864.qm at 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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