Re: anyone know what's going on in dw780_errchk

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

Brad Parker wrote:
> Is there anyone on the list know understand how the 780 sbi/unibus scan
> works?
> 
Hm, hopefully, I once wrote it :-)

> specifically, does anyone know what's going on in dw780_errchk?
> 
> I don't understand what that function does.  I don't have my 780 manuals
> with me at the moment.  I think it's looking at some sort of unibus
> bus error register.
> 
> the weird thing is that when I boot from the network the probe works fine
> for my uda, but when I boot from the mini root the probe fails.  The first
> time dw780_errchk is called it returns zero, the second time it returns 1
> because the *hej value is 0x10.  (sorry to be clueless right now).
> 
> is that a hardware error register?
> 
Yep.  And since the unibus adapter bits are clear-on-one the bits are just
read and written back to clear them.

(I probably thought the variable name hej was an exceptionally good name for
a status register variable 15 years ago :-)

-- Ragge