Re: VAX port internals etc...

[Anders Magnusson <ragge%ludd.ltu.se@localhost>]

On 01/24/2013 03:13 PM, Holm Tiffe wrote:
> Anders Magnusson wrote:
>
> > Hi Holm et al,
> [..]
> > So, any more questions that I have missed in the massive mail
> > conversations that has been last week? :-)
> >
> > -- Ragge
> At least one Question I have curently..
>
> You wrote in a post before I should disable that rebooting after an HALT
> for debugging purposes... hmm tried that, w/o much luck.
>
> There are 12 dip switches on that board (not 8 like I wrote before) and I
> tried to disable that but it doesn't work.
>
> If I power up the machine the value BOOT is empty (...) and HALT is set to
> 0x03 which should be correct.
> If I boot netbsd and it runs on a halt instruction that thing reboots,
> BOOT ist then set to eza0 and HALT to 0... and that damn thing is
> rebooting.
>
> Is it possible that the values somewhere in the RMA are overwritten from
> the Firmware itself or from some netbsd code? What could I try further to
> disable this reboots?
The action that should be taken on halt is usually defined in something 
called the console mailbox.
The rt300 seems to use ordinary memory for this, therefore it may be 
overwritten.  Look at
section 4.8.1.2 in the manual about this.

-- Ragge