VAX port internals etc...

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

Hi Holm et al,

now I'm back and can maybe answer a few questions I snapped up in the 
mail conversations.

The SIE (0x20040004) is just a number in the firmware PROM that can be 
used to find out which type of vax it is.  The SID tells only about the 
CPU architecture, which may differ in available instructions etc...

The SCB is an array of 64 interrupt handler addresses (vectors). Its 
content can be found in the VARM in section 6.6.  An interrupt has a 
specific priority level (there are 32 levels) and a vector to which it 
is associated.  In NetBSD there is a default handler for all possible 
vectors, and a specific vector is allocated via scb_vecalloc().  
Hardware devices usually use levels 0x14-0x17.

You do not need to attach the console driver to any bus at all, look at 
how gencons is written.

When init starts it will be the first time the cnopen routine is called.


So, any more questions that I have missed in the massive mail 
conversations that has been last week? :-)

-- Ragge